Introduction

This Book of Abstracts contains the plenary talk and poster abstracts to be presented at the 2nd NACP All-Investigators Meeting, February 17-20, 2009, in San Diego, California.

The book is organized as follows:

* Table of Contents (see PDF bookmarks for additional navigation)

* Plenary Talk Abstracts in chronological order by session.

* Poster Abstracts in chronological order by session, then presenter last name.

* Index of all authors, ordered by last name

This book is available online the meeting website at:

http://www.nacarbon.org/meeting_2009/ab_intro.htm

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Table of Contents

• Names in italics are Presenters.

Welcome / Opening Talks (Tuesday, February 17) 1.A Welcome (Peter Thornton, Peter Griffith) 1.B NACP Update (Paula Bontempi) 1.C NACP State-of-the-Science (Kenneth J. Davis, Tony King) 1.D Overview of the New Carbon Cycle Science Plan (Chris Sabine, Anna Michalak) Diagnosis/Attribution AM Talks (Tuesday, February 17) 2.A The North American carbon cycle as seen from the atmospheric perspective: Recent progress from the

NACP (Scott Denning, Arlyn Andrews, Martha Butler, Kathy Corbin, Kenneth J. Davis, Timothy Hilton, Andy Jacobson, Anna Michalak, Natasha Miles, Peter Rayner, Scott Richardson, Andrew Schuh, Thomas Lauvaux, Steven Wofsy)

2.B Nested Inversion of the North America Carbon Flux with Forest Stand Age and 13C Constraints (Jing M Chen, Feng Deng, Gang Mo, Mustapha El Maayar, Misa Ishizawa, Douglas Chan, Yude Pan, Richard Birdsey, Kevin McCullough, Michael Sprintsin)

2.C The European Carbon balance by atmospheric and terrestrial measurements: An update of the dual

constraint approach to derive a continental C-balance (Ernst-Detlef Schulze, Philippe Ciais, Sebastiaan Luyssaert, Jean-Francois Soussana, Pete Smith, Martin Heimann, Ivan Janssens)

Diagnosis/Attribution PM Talks (Tuesday, February 17) 3.A Observing and Modelling the Carbon Cycle of Northern Forests (Hank A Margolis, Robert F. Grant) 3.B Improved understanding of the impacts of disturbance on the carbon cycle of the NA boreal forest and

Western NA - integration of observations from field studies and analysis of remote sensing data into

process-based models (Eric S. Kasischke, A. David McGuire, Merritt R. Turetsky, Jennifer H. Harden, Nancy H.F. French, Laura L. Bourgeau-Chavez, Jill F. Johnstone, S. Yi, Elizabeth Hoy, Alex Schmid, Aditi Shenoy, Matthew Borr, Tatiana Loboda, Kirsten Barrett, Roger D Ottmar, Kristen Manies, Knut Keilland, William de Groot, Evan S. Kane, Mike Waddington, Mike Flannigan, Werner Kurz, Ron Hall, Claire Treat, Brian Benscoter, Daniel J. Hayes, David W. Kicklighter, Kevin R. Gurney, Todd J. Burnside, Jerry M. Melillo, Don McKenzie, Fengming Yuan)

3.C Carbon Measurements along the North American Continental Margins (Christopher L. Sabine, Richard A. Feely, Simone R. Alin, J. Martin Hernandez-Ayon, Debby Ianson, Burke Hales, Peter Strutton, Rik Wanninkhof, Tsung-Hung Peng, Doug Vandemark, Joe Salisbury, Wei-Jun Cai, Chris Langdon, Stacy Maenner, Sylvia Musielewicz)

3.D High resolution fossil fuel carbon emissions: progress, status and application to North American Carbon

Cycle research (Kevin Gurney, Robert Andres) Site Interim Synthesis Talks (Wednesday, February 18) 4.A Site-level synthesis of modeled and measured carbon, water, and energy fluxes across North America:

Evaluation of model and measurement uncertainty (Deb Agarwal, Brian Amiro, Ryan Anderson, Altaf M. Arain, Ian Baker, Dennis Baldocchi, Alan Barr, Andy Black, Tom Boden, Paul Bolstad, Sean Burns, Steve Campbell, Guangsheng Chen, Jing Chen, Philippe Ciais, Bob Cook, David Cook, Peter Curtis, Kenneth J. Davis, Steve Delgrosso, Michael Dietze, Dimitre Dimitrov, Danilo Dragoni, Howard Epstein, Matthias Falk, Marc Fischer, Larry Flanagan, Allen Goldstein, Michael Goulden, Robert F. Grant, Lianhong Gu, Niall Hanan, Iain Hawthorne, Tim Hilton, Forrest Hoffman,

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David Hollinger, Tara Hudiburg, Misa Ishizawa, Cesar Izaurralde, Jeff Nichols, Robin Kelly, Tony King, Christopher Kucharik, Peter Lafleur, Beverly Law, Zhengpeng Li, Leo Liu, Mingliang Liu, Erandi Lokupitiya, Yiqi Luo, Hank Margolis, Roser Matamala, Harry McCaughey, Tilden Meyers, Russell Monson, Bill Munger, Walt Oechel, Ram Oren, William Parton, Elizabeth Pattey, Changhui Peng, Philippe Peylin, ShiLong Piao, Mac Post, Ben Poulter, David Price, Brett Raczka, Dan Ricciuto, Andrew Richardson, William J. Riley, Michael Ryan, Alok Sahoo, Nick Saliendra, Crystal Schaaf, Kevin Schaefer, Andrew Schuh, Michael Sprintsin, Paul Stoy, Peter Thornton, Hanqin Tian, Christina Tonitto, Margaret Torn, Catharine van Ingen, Rodrigo Vargas, Hans Verbeeck, Shashi Verma, Nicolas Viovy, Weile Wang, Ensheng Weng, Christopher Williams, Xiaofeng Xu, Bai Yang, Wenping Yuan, Tianshan Zha, Xuhui Zhou)

4.B Regional to Continental Upscaling of AmeriFlux Data for Carbon Cycle Studies: Progress, Challenges, and

New Directions (Jingfeng Xiao, Kenneth J. Davis, Xuhui Zhou, Tao Zhou, Yiqi Luo, Christian Beer, Ben Bond-Lamberty, Ankur Desai, Martin Jung, Beverly E. Law, Leo Liu, Wilfred M. Post, Markus Reichstein, Daniel Ricciuto, Enrico Tomelleri, David Turner, Steven C. Wofsy, Bruce K. Wylie, Xiangming Xiao, Feihua Yang, Li Zhang, Maosheng Zhao)

MCI Interim Synthesis Talks (Wednesday, February 18) 5.A Synthesis of Tower CO2 Flux Observations in Key Agricultural Ecosystems in the MCI Region (S. B. Verma,

A. E. Suyker, J. M. Baker, J. L. Hatfield, T. P. Meyers, C. J. Bernacchi, T. J. Griffis, H. Yang, T. Setiyono, E. Lokupitiya) 5.B Inventory-based CO2 Budget for the MCI Interim Synthesis: Progress and Preliminary Results (Tristram O

West, Stephen M Ogle) 5.C Resolving CO2 Flux Estimates from Atmospheric Inversions and Inventories in the Mid-Continent Region

(Stephen M. Ogle, Dan Cooley, Scott Denning, Kenneth J. Davis, Tristram West, F. Jay Breidt) 5.D NACP’s Mid-Continent Intensive: Atmospheric Results (Natasha Miles, Arlyn Andrews, Kathy Corbin, Kenneth J.

Davis, Scott Denning, Douglas Martins, Scott Richardson, Paul Shepson, Colm Sweeney) Non-CO2/Greenhouse Gases Interim Synthesis Talks (Wednesday, February 18) 6.A Interim non-CO2 greenhouse gases synthesis results (Steve Wofsy) Regional Interim Synthesis Talks (Wednesday, February 18) 7.A North American Carbon Project (NACP) Spatial Model-Data Comparison Project (MDC) for Regional and

Continental Synthesis (Wilfred M. Post, Deborah N. Huntzinger, Andrew Jacobson, Robert B. Cook, Regional/Continental Interim-Synthesis Team Participants)

7.B Inverse Modeling (Andy Jacobson) 7.C The West Coast Regional Analysis (Beverly Elizabeth Law, Dave Turner, Mathias Goeckede, Warren B. Cohen,

Maureen Duane, Dave Ritts, Tara Hudiburg, Zhiqiang Yang, Chris Potter, Robert E. Kennedy) Coastal Interim Synthesis Talks (Wednesday, February 18) 8.A Toward understanding of carbon fluxes in the coastal oceans: synthesis activities for the U.S. East Coast

and the Gulf of Mexico (Steven Lohrenz, Wei-Jun Cai, Jim Bauer, Ron Benner, Tom Bianchi, Elizabeth Boyer, Fei Chai, Paula Cobble, Katja Fennel, Marjorie Friedrichs, Chuck Hopkinson, Brent McKee, Bill Miller, Ray Najjar, Cindy Pilskaln, Peter Raymond, Lisa Robbins, Joe Salisbury, Hanqin Tian, Doug Vandemark, Penny Vlahos, Jerry Wiggert)

8.B Recent (and Future) Advances in Carbon Cycle Synthesis along the North American Pacific Coast (Simone Alin, Andrew Dickson, Wiley Evans, Richard Feely, Burke Hales, Martin Hernandez-Ayon, Debby Ianson, Lauren Juranek, Carol Maloy, Jan Newton, Christopher Sabine, Peter Strutton, Phillippe Tortell, Verena Tunnicliffe, Bev Law)

8.C Diagnosing carbon dynamics in diverse ocean environments using in-situ optical and remotely- sensed

data. (Joe Salisbury, Amala Mahadevan, Bror Jonsson, Doug Vandemark, Christopher Hunt, Huijie Xue) Prediction Talks (Thursday, February 19)

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9.A The 20th century carbon budget simulated with the CCCma earth system model CanESM1 (Vivek K Arora,

George J Boer, Charles L Curry, James R Christian, Kos Zahariev, Kenneth L Denman, Gregory M Flato, John F Scinocca, William J Merryfield)

9.B When is the Permafrost Carbon Tipping Point? (Kevin M Schaefer, Tingjun Zhang, Lori Bruhwiler) 9.C Assimilation of Multiple, Heterogeneous Data Sets to Enhance Predictability of Future Carbon Sink

dynamics in the North America Terrestrial Ecosystems (Yiqi Luo, Nathan M Urban, Kenneth J. Davis, Klaus Keller, Peter Thornton, Mac Post, Ensheng Weng)

9.D A New Method for Evaluating the Ocean Acidification of Coastal Waters Using Chemical and Hydrographic

Data (Richard Alan Feely, Burke Hales, Chris Sabine, Dana Greeley, Kitack Lee, Simone Alin, Laurie Juranek) Decision Support Talks (Friday, February 20) 10.A Monitoring Requirements for Greenhouse Gas Markets and Registries (Richard Birdsey, Linda Heath, Coeli

Hoover) 10.B Land use decision making as a driver of carbon sequestration at multiple scales: A Colorado case study

(Lisa Dilling, Elisabeth Failey) 10.C Carbon budget of Canada’s managed forest derived from a combined inventory and modeling approach

(Werner Alexander Kurz, Graham Stinson, Eric Neilson, Caren Dymond, Celine Boisvenue, Juha Mikael Metsaranta, Brian Nelson Simpson)

Diagnosis Posters (Tuesday, February 17) 1 A Latitudinal, Longitudinal, and Monthly Description of the Fossil-Fuel-Carbon-Dioxide Emissions for the

Countries of the North American Carbon Program (Robert J Andres, Tom A Boden, Jay S Gregg, London Losey, Gregg Marland)

2 Gross Primary Productivity Response to Modes of Climate Variability (Ian T Baker, A Scott Denning, Kevin Schaefer, Lara Prihodko)

3 Measurements of the ecosystem O2-CO2 stoichiometry at Harvard Forest (Mark O Battle, Zane A Davis, Ryan Hart, Eric Sofen, Rebecca Perry, Jayme Woogerd, Jacob Scheckman, John Carpenter)

4 Detrital carbon pools in temperate forests: magnitude and potential for landscape-scale assessment (John B Bradford, Peter Weishampel, Marie L. Smith, Randall Kolka, Richard A Birdsey, Scott V Ollinger, Michael G Ryan)

5 Chamber-Based Estimates of Methane Production in Coastal Estuarine Systems in Southern California (Brian Brigham, David Lipson, Chun-Ta Lai)

6 Airborne Laser Remote Measurements of Atmospheric Carbon Dioxide (Edward V. Browell, Michael E. Dobbs, Jeremy Dobler, Susan A. Kooi, Yonghoon Choi, F. Wallace Harrison, Berrien Moore III, T. Scott Zaccheo)

7 Spatiotemporal distributions of atmospheric CO2 from high resolution in-situ measurements over North

America during NASA Field Campaigns (2004-2008) (Yonghoon Choi, Stephanie A. Vay, Jung-Hun Woo, Kichul Choi, Krishna P. Vadrevu, Edward V. Browell, Susan A. Kooi)

8 Mapping Forest Crown Cover, Mean Canopy Height, and Aboveground Biomass using a Geometric-Optical

Model and MODIS Data (Mark James Chopping, Crystal Schaaf, Feng Zhao, Zhuosen Wang) 9 Probabilistic upscaling of eddy flux measurements in the upper Great Lakes: Working towards the next

generation MODIS GPP algorithm (Kenneth J. Davis, Jingfeng Xiao, Ryan Anderson, Paul Bolstad, Kelly Cherrey, Bruce Cook, Ankur Desai, Randy Kolka, Steve Running, Nicanor Saliendra, Ben Sulman, Peter Weishampel)

10 Carbon pools and fluxes in a coastal plain loblolly pine plantation (Michael Gavazzi, Asko Noormets, Steve McNulty, Ge Sun, JC Domec, John King, Jiquan Chen, Emrys Treasure)

11 The Vulcan Project: Methods, Results, and Evaluation (Kevin Robert Gurney, Daniel Mendoza, Marc Fischer, Kathy Corbin, Chris Miller, Bedrich Benes, Nathan Andrysco, Simon Ilyushchenko, Stephanie de la Rue du Can, Scott Denning, Dennis Ojima)

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12 The Carbon Balance of North American High-latitude Terrestrial Ecosystems in Response to Changes in

Atmospheric Chemistry, Climate and Disturbance Regime (Daniel J Hayes, A David McGuire, David W Kicklighter, Jerry M Melillo)

13 Forest dynamics in southeastern United States assessed using time series stacks of Landsat observations (Chengquan Huang, Ainong Li, Hua Shi, James Vogelmann, Zhiliang Zhu, Chris Toney, Nancy Thomas, Samuel N. Goward, Jeffrey G Masek)

14 The Resolution of the North American CO2 Observing Network as Seen by CarbonTracker (Andrew R Jacobson, Arlyn E Andrews, Kenneth A Masarie, Colm Sweeney, Wouter Peters, John B Miller, Thomas J Conway, James H Butler, Pieter Tans)

15 Residential Carbon: Characterizing the carbon cycle in urban grasslands (Jennifer C Jenkins, Peter M Groffman, John Butnor, Paul J. Lilly, Amanda K. Holland, Mary Cadenasso)

16 Northeastern US forest response to changing climate and atmospheric chemistry (Julian P Jenkins, Scott V Ollinger, Christine Goodale, Christina Tonitto)

17 Net radiation and evapotranspiration estimated with satellite observations (Yufnag Jin, Jim Randerson, Mike Goulden)

18 Biogeochemical, Remote Sensing, and Modeling Approaches to Evaluating the Sources and Fates of

Dissolved Organic Matter and Particles in the U.S. Middle Atlantic Bight (Antonio Mannino, Stan B. Hooker) 19 Estimating the Amount, Spatial Distribution, and Statistical Uncertainty of Aboveground Carbon Stocks of

the North American Boreal Forest Using the ICESAT-GLAS Spaceborne Lidar (Ross F Nelson, Hank A Margolis, Hans E Andersen, Mike Wulder)

20 Remotely sensed respiration vs. primary production in a coastal ocean ecosystem (Patricia Matrai, Nicole Poulton, Carlton Rauschenberg, Michael Sieracki)

21 Integrating surface and space-based observations of atmospheric CO2 for inverse modeling of CO2 sources

and sinks (Ray Nassar, Dylan B.A. Jones, Jing M. Chen) 22 Estimation of the interannual variation of CO2 exchange between North American terrestrial ecosystems

and the atmosphere using the simulation model GTEC (Wilfred M. Post, Anthony W. King, Lianhong Gu, Jesse N. Miller, Shuyong Li)

23 Potential of Tracking Respiration Flux of North American Temperate Deciduous Forests Using MODIS

Reflective and Thermal Image Data (A. Faiz Rahman, Vicente D. Cordova) 24 International Cooperation to Provide Consistent Landsat-based Estimates of Forest Carbon Change in North

America (Todd A. Schroeder, Sean P. Healey, Gretchen G. Moisen, Michael A. Wulder, Rigoberto Rivas Palafox, Samuel N. Goward, Warren B. Cohen, Jeff B. Masek, Robert E. Kennedy, Chengquan Huang, Scott L. Powell, Nancy Thomas, Karen Schleeweis)

25 From Forest Structure To Forest Ecology: Relationships Between Forest Profiles from Interferometric SAR,

Leaf Area Density, Biomass, and Ecosystem History (Robert Treuhaft, Fabio Goncalves) 26 Analysis of ARCTAS airborne CO2 measurements using geotechniques (Krishna Prasad Vadrevu, Yonghoon

Choi, Stephanie A Vay) 27 Mapping Canadian Wetlands Using L-band Radar Satellite Imagery (Jane Whitcomb, Mahta Moghaddam, Kyle

mcDonald, Erika Podest) 28 Decadal Change in Wetlands of Alaska Based on Analysis of ALOS/PALSAR and JERS SAR Data (Jane

Whitcomb, Mahta Moghaddam, Kyle mcDonald, Erika Podest, Bruce Chapman) 29 Continuous Measures of Net Ecosystem Carbon Exchange and Gross Primary Productivity for the

conterminous United States Derived from MODIS and AmeriFlux Data (Jingfeng Xiao, Qianlai Zhuang) 30 Assessment of the impacts of biofuel crops on the carbon, water, and nitrogen cycles in Central Illinois

(Marcelo Zeri, Andrew VanLoocke, George Hickman, Carl Bernacchi) Attribution Posters (Tuesday, February 17) 31 Quantifying Changes in High Latitude Ecosystems of Alaska and Northeastern Russia in Response to

Climate and Fire Disturbance (Scott J Goetz, Michelle Mack, James T Randerson, Yufang Jin, Pieter Beck) 32 Changes in boreal forest growth from the ground up: relating boreal tree growth to remotely sensed

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photosynthetic activity (Pieter Beck, Scott Goetz, Claire Alix, Glenn Juday, Andy Bunn, Andrea Lloyd) 33 An Estimate of the Tree Carbon Sink Due to Fire Reduction in California Montane Conifer Forests. (Jim

Bouldin) 34 High temporal density change detection with Landsat imagery to quantify juniper expansion in eastern

Oregon (John Campbell, Robert Kennedy, David Azuma, Rick Miller, Warren B. Cohen) 35 Quantifying the influence of climate and land use change on primary production using carbonyl sulfide

measurements (John Elliott Campbell, Joe A. Berry) 36 Disturbance and Carbon Fluxes of Canadian Forests (Carole Coursolle, Hank A. Margolis, Marc-André Giasson,

Operational Science Committee) 37 Modelling of hydrological and thermal controls on carbon dioxide exchange at Mer Bleue bog (Dimitre D.

Dimitrov, Robert F. Grant, Elyn Humphreys) 38 pCO2 observations from the British Columbia and Alaska coastal margin (Wiley Evans, Burke Hales, Peter

Strutton) 39 Monitoring of gross primary productivity of crops using Landsat data (Anatoly A Gitelson, Andrés Viña, Jeffrey

G Masek, Shashi B Verma, Andrew E Suyker) 40 Quantifying Organic and Mineral Soil Carbon Turnover Along Climate Gradients: The EBIS-AmeriFlux

Project (Paul J. Hanson, Karis McFarlane, Susan E. Trumbore, Tom Guilderson, Margaret S. Torn, Roser Matamala, Julie Jastrow, Mac A. Callaham, William J. Parton Jr., EBIS-AmeriFlux Site Operators)

41 Quantifying Soil Carbon Cycle Mechanisms and Flux Using 14C-Enriched Leaf Litter Manipulations:

Implications for Modeling Carbon In Soil (Paul J. Hanson, Mats J. Froberg, Chris Swanston, Susan E. Trumbore, Margaret S. Torn, Julie Jastrow, Tom Guilderson, William J. Parton)

42 Daily emissions of CO2, CO and CH4 from biomass burning in the United States in 2006 and 2007 and the

impact on North American carbon cycle (Wei Min Hao, Shawn P. Urbanski, Bryce L. Nordgren, Alex Petkov) 43 Assessing the impacts of bark beetle outbreaks on carbon budgets in the western United States (Jeffrey A.

Hicke, Eric Pfeifer, Arjan J.H. Meddens, Ryan Sheridan) 44 Remote Sensing of Vegetation Light Use Efficiency Dynamics (Karl Fred Huemmrich, Elizabeth M. Middleton,

Lawrence A. Corp, Yen-Ben B. Cheng, Petya K. Entcheva Campbell, Qingyuan Y. Zhang, Andrew L. Russ, William P. Kustas, John H. Prueger)

45 Will Elevated Atmospheric CO2 Change Soil Carbon Stocks in Tilled Corn-Soybean Rotation Agroecosystems

of the U.S. Midwest? (Kelly K. Moran, Julie D. Jastrow) 46 Incorporation of Root and Surface Litter Inputs Into Soil C Pools: What Do Different Physical Fractionation

Approaches Tell Us? (Julie D. Jastrow, Christopher W. Swanston, Sarah L. O'Brien, Kelly K. Moran, Rachel C. Porras, Margaret S. Torn, Paul J. Hanson)

47 Hierarchical Controls on the Accrual of Physically Protected Soil Carbon Pools Following Tallgrass Prairie

Restoration (Sarah L. O'Brien, Julie D. Jastrow, Miquel A. Gonzalez-Meler) 48 Soil Carbon and Nitrogen Dynamics in a Deciduous Forest Exposed to Ten Years of Atmospheric CO2

Enrichment (Julie D. Jastrow, Kelly K. Moran, Sarah L. O'Brien, Thomas W. Boutton) 49 Controls on the spatial distribution of soil organic carbon in black spruce forests (Kristofer Johnson, David

McGuire, Shuhua Yi, Jennifer Harden, Kristen Manies) 50 Carbon Emissions from the 2004 Alaskan Fires (Eric S. Kasischke, Elizabeth Hoy, Merritt R. Turetsky, Evan S.

Kane, Roger D. Ottmar, William de Groot, Jennifer H. Harden, Kristen Manies, Nancy H.F. French) 51 Estimation of biennial forest disturbance rates for the conterminous United States (Robert E Kennedy,

Samuel N. Goward, Warren B. Cohen, Jeffrey G Masek, Gretchen Moisen, Chengquan Huang, Karen Schleeweis, Nancy Thomas, Sean Healey, Scott Powell)

52 Interannual variability in the temperature-responsiveness of CO2 flux from forest and peatland soils (Randy K Kolka, Peter Weishampel, Jennifer Y King)

53 Dissolved organic matter production and stabilization across pedogenic thresholds (Marc Gerald Kramer, Jonathan Sanderman)

54 Modeling impacts of physiological response and species composition on ecosystem respiration with carbon-

13 measurements (Chun-Ta Lai, James Ehleringer) 55 Modeling CO2 emissions in Prairie Pothole region using DNDC model and remotely sensed data (Zhengpeng

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Li, Shuguang Liu, Robert Gleason) 56 Wall-to-Wall Forest Dynamics For NACP Modeling (Jeffrey Masek, Robert Wolfe, Samuel N. Goward, Chengquan

Huang, Gretchen Moisen, Warren B. Cohen, Feng Gao, Forrest Hall) 57 Monitoring of Landscape Freeze-Thaw in the Terrestrial High Latitudes with Satellite Microwave Remote

Sensing: Relationships with Growing Season and Land-Atmosphere CO2 Exchange (Kyle C McDonald, John S Kimball, Ke Zhang, Youngwook Kim, David Ganem, Erika Podest)

58 Using radiocarbon measurements to evaluate fossil fuel emission inventories. (John B Miller, Scott J Lehman, Colm Sweeney, Pieter P Tans)

59 Estimating Photochemical Contributions to Coastal Carbon Cycles from Remote Sensing (William L. Miller, Heather Reader, Cedric G. Fichot)

60 Using a Sample of Temporally Dense Landsat-based Disturbance Maps to Explore and Map Rates of Forest

Disturbance across the Conterminous U.S. from 2000 to 2006 (Gretchen G. Moisen, Jock A. Blackard, Sean P. Healey, Samuel N. Goward, Warren B. Cohen, Jeffrey G. Masek, G. James Collatz, Michael A. Wulder, Chengquan Huang, Robert Kennedy, Scott Powell, Nancy Thomas, Karen Schleeweis, Adrienne Hinds, Khaldoun Rishmawi)

61 Carbon Stocks and Fluxes in Temperate Forest Ecosystems of Nuevo Leon, Mexico (Jose de Jesus Navar) 62 Near-surface remote sensing of spatial and temporal variation in canopy phenology (Andrew D Richardson,

Bobby H Braswell, David Y Hollinger, Julian P Jenkins, Scott V Olliner) 63 Landscape Structure Controls Soil CO2 Efflux Variability in Complex Terrain: Scaling From Point

Observations to Watershed Scale Fluxes (Diego A. Riveros-Iregui, Brian L. McGlynn, Howard E. Epstein, Daniel Welsch, Ryan Emanuel, Daniel Muth)

64 Snow, Soil Freeze/Thaw Dynamics, and the Carbon Cycle (Kevin Schaefer, Tingjun Zhang, Lixin Lu) 65 Spatial and Temporal Variability of Frozen Ground and Snow Cover in the Northern Hemisphere (Tingjun

Zhang, James McCreight, Kevin Schaefer) 66 Interannual variation of carbon fluxes from a tropical, a temperate, and a boreal evergreen forest: the role

of forest dynamics and climate (Carlos A Sierra, Mark E Harmon) 67 Identification of greenhouse gas source signatures in the San Francisco Bay area using in situ aircraft

measurements (Anna Karion, Marc Fischer, Doug Day, Colm Sweeney, Tom Sherwood, Nenad Zagorac, Suman Saripalli, Ian Faloona, Stephen Montzka, Ben Miller, Lloyd Miller, Chuanfeng Zhao, Janusz Eluszkiewicz, Thomas Nehrkorn)

68 Temperature responses of soil carbon dynamics and its implication for regional carbon balance in Yukon

River Basin, Alaska (Bo Tao, Shuguang Liu, Zhengxi Tan) 69 Seeing the trees for the forest: Nitrogen deposition alters tree carbon gain and survival across the

northeastern U.S., responses vary by species. (R. Quinn Thomas, Charles D. Canham, Kathleen C. Weathers, Christine L. Goodale)

70 Attributing and predicting changes in regional carbon budget in Southeastern US during 1900-2050

through data-model integration (Hanqin Tian, Chi Zhang, Guangsheng Chen, Mingliang Liu, Wei Ren, Xiaofeng Xu, Chaoqun Lu, Art Chappelka, Ge Sun, Shufen Pan, Bray Bray Beltran Villarreal, Xia Song)

71 Regional-Scale Airborne Observations of 14CO2 over North America and Adjacent Oceans (Stephanie A. Vay, Stanley C. Tyler, Donald R. Blake, Yonghoon Choi, Nicola J. Blake, Glen W. Sachse, Glenn S. Diskin)

72 Climate and Disturbance Effects on Forest Productivity in Oyster River and Chibougamau Study Areas (Ziyu Wang, Robert F. Grant, Altaf Arain, Pierre Bernier, Bin Chen, Jing Chen, Nicholas Coops, Ajit Govind, Luc Guindon, Robbie Hember, Werner Kurz, Changhui Peng, David Price, Graham Stinson, Jianfeng Sun, Tony Trofymow, Jagadeesh Yeluripati)

74 North American Vegetation Phenology Derived From Temporally Smoothed and Gap-Filled MODIS data (Robert E Wolfe, Bin Tan, Jeffery T Morisette, Feng Gao, Gregory A Ederer, Joanne M Nightingale, Jeffery A Pedelty)

75 Satellite based analysis of recent changes in ET and the terrestrial water balance over Canada and Alaska:

Implications for vegetation productivity and the northern carbon cycle (Ke Zhang, John S Kimball, E. H. Hogg, Kyle C. McDonald, Walter C. Oechel)

Tools/Instruments/Data Posters (Tuesday, February 17) 76 Modeling and Synthesis Support for the North American Carbon Program (Robert B. Cook, Wilfred M. Post,

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Peter E. Thornton, Latha M. Baskaran, Lisa M. Olsen, Michele M. Thornton, Carroll N. Curtis, Jerry Y. Pan, Yaxing Wei, Steve L. Campbell)

77 The Wildland Fire Emissions Information System: Providing information for carbon cycle studies with open

source geospatial tools (Nancy HF French, Tyler A Erickson, Donald McKenzie) 78 Exploring Research Contributions of the North American Carbon Program using Google Earth (Peter Griffith,

Lisa Wilcox, Amy Morrell) 79 Measuring Gross Ecosystem PRoduction Directly from Remote Sensing (Forrest G Hall, Thomas Hilker,

Nicholas C Coops) 80 The Carbon-Land Model Intercomparison Project (C-LAMP): A Protocol and Metrics for Model-Data

Comparison (Forrest M Hoffman, James T Randerson, Inez Y Fung, Peter E Thornton, Curtis C Covey, Gordon B Bonan, Steven W Running)

81 News and Notes from the Land Processes Distributed Active Archive Center (Calli B. Jenkerson, David J. Meyer)

82 Spatial Data Services and Forest Inventory and Analysis Data (Elizabeth LaPoint) 83 Open-Path Gas Analyzer for Eddy Covariance Measurements of Methane Flux (George Burba, Tyler Anderson,

Donatella Zona, Jessica Schedlbauer, Steven Hastings, Hiroki Ikawa, Dayle McDermitt, Steven Oberbauer, Walter Oechel, Gregory Starr, Cove Sturtevant, Liukang Xu)

84 Mountaintop Inter-Comparison Of NOAA/ESRL Trace Gas Measurement Systems (D. Neff) 85 Developing an accuracy assessment protocol for Forest Inventory and Analysis (FIA) geospatial datasets

(Rachel Riemann, Barry Tyler Wilson) 86 Accurate retrievals of forest structure and biomass from the Echidna® ground-based, upward-scanning

lidar (Alan Strahler, Curtis Woodcock, Crystal Schaaf, David Jupp, Darius Culvenor, Glenn Newnham, Wenge Ni-Meister, Feng Zhao, Tian Yao, Xiaoyuan Yang)

87 Non-Destructive Belowground Carbon Observations from Organic Soils to Mine Overburden: Recent

Progress (Lucian Wielopolski) Prediction Posters (Thursday, February 19) 88 Simulation of Terrestrial Ecosystem Dynamics, Past and Future: A Nested Scale Experiment (NeScE), a

Mythical Beast (Ronald P Neilson, James M Lenihan, Dominique Bachelet, Raymond J Drapek, Chris Daly, John R Wells, Maureen McGlinchy, Brendan Rogers, Guy Pinjuv, Patrick Gonzalez)

89 Incorporating landscape-scale edaphic variation into regional ecosystem forecasts using ED2 (Michael Dietze, Paul Moorcroft, Andrew Richardson)

90 N Limitation and Terrestrial C Storage: Scaling from microns to the globe through data synthesis and

modeling. (Adrien C. Finzi, Peter E. Thornton, Christine L. Goodale) 91 Towards detection of the changing North America carbon sink (Inez Fung, Nir Krakauer, Zan Stine, Abby

Swann) 92 Thermokarst dynamics and related carbon cycling in ice-rich permafrost in NW Alaska (Guido Grosse, Katey

Walter, Lawrence Plug, Vladimir Romanovsky, Mary Edwards, Lee Slater) 93 Interactive effects of disturbance, rising CO2 concentrations, nitrogen deposition and climate on carbon

cycle dynamics of US West-Coast forests (Tara Hudiburg, Peter Thornton, Beverly Law) 94 Black Carbon Stocks as Carbon Sinks in Soils of the United States (Verena Jauss, Johannes Lehmann, Peter

Woodbury, Evelyn Krull) 95 Quantifying variations of sources and delivery of organic carbon from continental US induced by multiple

environmental stresses by using integrated system of the Dynamic Land Ecosystem Model and Nutrient

Export (DLEM-NE) (Mingliang Liu, Hanqin Tian, Chi Zhang, Guangsheng Chen, Bray Beltran Villarreal, Xiaofeng Xu, Chaoqun Lv, Wei Ren)

96 Atmospheric Methane Contributions From Fractured Bedrock Aquifers (D.L. Marrin) 97 Carbon Consequences of Regional Land Cover Changes in North America (Chrisotpher S.R. Neigh, Nuno

Carvalhais, G Jim Collatz, Compton Jim Tucker)

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98 Nitrogen Limitation is Reducing the Enhancement of NPP by Elevated CO2 in a Deciduous Forest (Richard J Norby, Jeffrey M Warren, Colleen M Iversen, Belinda E Medlyn, Ross E McMurtrie)

99 CO2- Enhanced Precipitation Use Efficiency and Carbon Sequestration in Terrestrial Ecosystems of North

America (Yude Pan, Richard Birdsey, Kevin McCullough, Robert Nowak, Ram Oren) 100 Climate Change Effects on Vegetation Distribution and Carbon Storage in the Pacific Northwest (Brendan M

Rogers, Ronald P Neilson) 101 A National Soil Carbon Network: Concept, organization, and participation. (Chris Swanston, John Baker,

Richard Birdsey, Ronald Follet, Jennifer Harden, Julie Jastrow, Mark Johnson, Johannes Lehmann, Randy Kolka, Robert Mckane, William Parton, Wilfred Post, Peter Thornton, Margaret Torn, Sue Trumbore, Eric Vance, Mark Waldrop, Larry West)

102 Evaluating Forest Disturbance for the North American Carbon Program: Ongoing Research in the North

American Forest Dynamics (NAFD) Study (Nancy E. Thomas, Samuel N. Goward, Jeffrey G. Masek, Warren B. Cohen, Gretchen G. Moisen, Chengquan Huang, Sean Healey, Robert Kennedy, Scott Powell, Karen Schleeweis, Khaldoun Rishmawi, Adrienne Hinds)

103 Exploring mechanisms that affect carbon storage in forest soils: Simulations from the PnET-SOM model (Christina Tonitto, Christine L. Goodale, Scott V. Ollinger, Julian P. Jenkins)

104 Carbon consequences of forest disturbance and recovery across North America (Christopher A Williams, G James Collatz, Jeffrey G Masek)

105 Complexity, global climate change, and the factors controlling soil carbon cycling (Devin Wixon, Teresa Balser)

106 Enhancing and Extending the North American Carbon Sink by Sustainable Wood Burial and Storage (Ning Zeng, Jay Gregg, Ben Zaitchik, Brian Cook)

107 Enhanced sources of atmospheric C from “stable” pools of soil organic C (Sharon Alene Billings, Susan E. Ziegler)

Decision Support Posters (Thursday, February 19) 108 Landscape-scale Monitoring of the Forest Carbon Cycle (Richard Birdsey, Coeli Hoover, Linda Heath, Kenneth J.

Davis, John Bradford, David Hollinger, Michael Ryan, Yude Pan, John Hom, Kenneth Clark) 109 Soil carbon storage in the Southern Appalachians across a gradient of land use: forests, pastures, and

Christmas tree farms (Samantha Chapman, Adam Langley) 110 The transition to cellulosic biofuels under three levels of NPP (Francis J Pierce, Harold P Collins, Daniel S Long,

Stephan L Albrecht, Stephen J Fransen, Eileen M Perry, Stephen L Young) 111 Mapping Soil Organic Carbon in the U.S. Corn Belt (Paul Doraiswamy, Hector Causarano, Cesar Izaurralde, Craig

Daughtry, Jerry L. Hatfield) 112 An update of the organic carbon found in soils of Mexico (J. D. Etchevers, C. O. Cruz, C. Balbontin, F. Paz, B. de

Jong) 113 Selective Stabilization of Root and Leaf-Derived Lignin and Aliphatic Biopolymers among Soil Organic

Matter Fractions: Comparison of Ambient and Elevated Atmospheric CO2 Rings in the Sweetgum Free Air

CO2 Enrichment (FACE) Experiment. (Timothy R. Filley, Julie D. Jastrow, Sarah L. O'Brien, Kelly K. Moran, Thomas W. Boutton)

114 A method for measuring and monitoring carbon stores in the above and belowground compartments of two

vegetation types of the tropical subhumid regions of Mexico (Jesus David Gomez, Jorge Dionicio Etchevers, Julio Campo, Alejandro Ismael Monterroso)

115 Rapid Assessment and Modeling of Soil Carbon Pools across Florida (Sabine Grunwald, Brenton D. Myers, Willie G. Harris, Nicholas B. Comerford, Gregory L. Bruland)

116 Synthesis of Forest Carbon Dynamics at the Landscape Level (Sean P. Healey, Todd Morgan, Shawn Urbanski, Loeffler Dan, Greg Jones, Blackard Jock, Moisen Gretchen, DeBlander Larry, Frescino Tracey)

117 Carbon Consequences of Thinning: Initial Results from Long-Term Studies on Experimental Forests (Coeli M Hoover)

118 The National Biomass and Carbon Dataset 2000: A high-resolution baseline of conterminous U.S. Biomass

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and Carbon Stocks from InSAR/Optical Fusion (Josef Kellndorfer, Wayne Walker, Katie Kirsch, Greg Fiske, Elizabeth LaPoint, Mike Hoppus, James Westfall)

119 Is Iowa Currently a Carbon Sink? GEMS Simulated Changes in Ecosystem Carbon Stocks and Fluxes from

1972 to 2007 (Shuguang Liu Liu, Zhengxi Tan, Zhengpeng Li, Shuqing Zhao, Wenping Yuan) 120 The Legacy of Invasive Species on Ecosystem Carbon Dynamics in a Restored Tallgrass Prairie (Roser

Matamala, Scott Graham, David R Cook, Miquel A Gonzalez-Meler, Michael Ritchie) 121 Biotic and Abiotic Factors Controlling Soil Respiration Partitioning in a Tall Grass Prairie (Nuria Gomez-

Casanovas, Roser Matamala, David R Cook, Miquel A Gonzalez-Meler) 122 Temporal Changes in C and N Stocks of Restored Prairie. Implications for C Sequestration Strategies

(Roser Matamala, Julie D Jastrow, Michael R Miller, Charles Jr T Garten) 123 Fuel loading and consumption models for assessing carbon release from wildland fires (Don McKenzie,

Roger D Ottmar, Nancy French) 124 Storage and fluxes of carbon in the United States predicted from satellite data, ecosystem modeling, and

inventory summaries: Synthesis and new focus on linkages to NASA’s Orbiting Carbon Observatory (OCO)

Mission (Christopher Potter, Steven Klooster) 125 Carbon Dynamics and Models on Land-use/cover Basis: Analysis from a Himalayan Watershed (Purnima

Sharma, S C Rai) 126 Regional Environmental Impacts of Biofuel Feedstock Production—Scaling Biogeochemical Cycles in Space

and Time (Andy David VanLoocke, Carl J Bernacchi, Tracy E Twine) 127 Predicting Net Carbon Flux with Expected Changes in U.S. Agriculture: Some Potential Impacts of

Bioenergy Crops in the U.S. Carbon Budget (Tristram O West, Craig C Brandt, Chad M Hellwinckel, Robert D Perlack, Latha M Baskaran, Daniel G De La Torre Ugarte, Mark E Downing, Bradly S Wilson, Richard G Nelson)

128 Impacts of Future Scenarios of Land Cover and Climate Change on Ecosystem Carbon Sequestration in the

Southeastern United States (Shuqing Zhao, Shuguang Liu, Zhengpeng Li, Terry Sohl) Site Synthesis Posters (Thursday, February 19) 129 A decadal study of soil carbon cycling on decadal time scales (Eric A Davidson, Susan E Trumbore) 130 Biometric and Eddy-Covariance Methods: Integrated Carbon Flux Analysis in a Mid-Latitude Deciduous

Forest (Danilo Dragoni, Craig A Wayson, James C Randolph, Hans Peter Schmid) 131 Interannual Variation in Net Ecosystem Productivity of Canadian Forests as Affected by Regional Weather

Patterns - a Fluxnet-Canada Synthesis (Robert F. Grant, Alan G. Barr, T. Andrew Black, Hank A. Margolis, Allison L. Dunn, Shusen Wang, Pierre Y. Bernier)

132 Estimates of terrestrial carbon cycle model parameters by assimilation of FLUXNET data: Do parameter

variations cause bias in regional flux estimates? (Daniel M Ricciuto, Anthony W King, Lianhong Gu, Wilfred M Post)

133 Improving carbon flux predictions in North America from the bottom up: The current state of eddy

covariance based model-data fusion (Daniel M Ricciuto, Kenneth J. Davis, Ankur R Desai, Andrew M Fox, Michael C Dietze, Shuguang Liu, Yiqi Q Luo, Andrew D Richardson, Kevin Schaefer, Mathew Williams)

134 Site Level Evaluation of MODIS Albedo and Reflectance Anisotropy Gap-free Products for NACP (Crystal B. Schaaf, Miguel O. Román, Qingling Zhang, Zhuosen Wang, Xiaoyuan Yang, Curtis Woodcock, Alan H. Strahler)

135 A geostatistical synthesis study of factors affecting net ecosystem exchange in different ecosystems of

North America (Vineet Yadav, Anna M Michalak, Kim Mueller) 136 Uncertainties in carbon residence time and sequestration in terrestrial ecosystems of the conterminous

USA: A Bayesian approach (Xuhui Zhou, Tao Zhou, Yiqi Luo) Regional Synthesis Posters (Thursday, February 19) 137 The North-South gradient of CO2 in the free troposphere during summer: Implications for surface

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exchange. (Gretchen Keppel Aleks, Paul O Wennberg, Tapio Schneider, Stephanie A Vay) 138 Validation of High Temporal Density Landsat Time Series Disturbance Maps to Constrain Carbon Flux

Estimates from NACP Ecosystem Process Models (Warren B. Cohen, Zhiqiang Yang, Robert E. Kennedy, David P. Turner, Bev E. Law, Samuel N. Goward, Jeffrey G. Masek, Gretchen G. Moisen, Chengquan Huang, Jim Collatz)

139 Modeling Global Atmospheric CO2 Fluxes and Transport Driven by Assimilated Meteorology (S R Kawa, G James Collatz, A Scott Denning, David J Erickson, Steven C Wofsy, Arlyn E Andrews)

140 Contrasting the seasonal patterns of ecosystem-level photosynthesis, gross light-use efficiency and

respiration across the circumpolar boreal region - a first cut (Guillaume Drolet, Hank A. Margolis, Elizabeth M. Middleton, Anders Lindroth, David Hollinger)

141 Ensemble Ecosystem Model Experiment and Intercomparison using the Terrestrial Observation and

Prediction System (TOPS) (Weile Wang, Jennifer L. Dungan, Andrew Michaelis, Hirofumi Hashimoto, Ichii Kazuhito, Ramakrishna Nemani)

142 CO2 Exchange and Budget of Natural and Agricultural Ecosystems across the Great Plains of North America:

Integration of Flux Tower Data (Tagir G Gilmanov, Larry L Tieszen, Bruce K Wylie, Li Zhang, John M Baker, Carl J Bernacchi, David P Billesbach, James A Bradford, David R Cook, Richard L Coulter, Andrew G Detwiler, William A Dugas, Lawrence B Flanagan, Albert B Frank, Timothy J Griffis, Marshall R Haferkamp, Jay M Ham, James L Heilman, Mark W Heuer, Steven E Hollinger, Roser Matamala, Tilden P Meyers, Patricia C Mielnick, Jack A Morgan, Clenton E Owensby, John H Prueger, Phillip L Sims, Margaret S Torn)

143 The ORCA West Coast Regional Project - Constraining Carbon Budgets on Regional Scales using

Atmospheric Inverse Modelling Techniques (Mathias Goeckede, Anna Michalak, Dean Vickers, David Turner, Beverly Law)

144 Role of Forest 'Disturbance' and Regrowth in North American Carbon Balance (Samuel N. Goward, Warren B. Cohen, Jeffery G. Masek, Gretchen Moisen)

145 Influences of the spatial and temporal resolutions of CO2 concentrations on model estimates of terrestrial

carbon budget: Implications for the ASCENDS (Lianhong Gu, Tony King, Mac Post, Dan Riciutto) 146 Estimating bias of scaling effects on satellite based forest area estimation for the conterminous U.S.

(Daolan Zheng, Linda S. Heath, Mark J. Ducey) 147 Spatial Structure in North American Regional CO2 Fluxes Evaluated With a Simple Land Surface Model

(Timothy W Hilton, Kenneth J. Davis) 148 Comparing estimates of North American biospheric carbon flux from process-based models: New tools for

understanding differences in predictions (Deborah N Huntzinger, Kim L Mueller, Sharon J Gourdji, Anna M Michalak)

149 Regional CO2 Fluxes Estimated over North America for 2004 using a Geostatistical Inverse Model (Sharon M Gourdji, Kim L Mueller, Deborah N. Huntzinger, Vineet Yadav, Adam I Hirsch, Arlyn E Andrews, Anna M Michalak)

150 Vulnerability of North American black spruce forests to changes in post fire succession (Eric S. Kasischke, Jill F. Johnstone, Merritt R. Turetsky, Laura L. Bourgeau-Chavez, Aditi Shenoy, Knut Keilland, Matthew Borr, Kirsten Barrett, Elizabeth Hoy, Tatiana Loboda, A. David McGuire, T. Scott Rupp)

151 Synthesizing Prediction Uncertainty From Interim Syntheses (Anthony Wayne King, Wilfred M Post, Dan Ricciuto)

153 Measuring regional CO2 fluxes using a Lagrangian approach (Douglas K Martins, Colm Sweeney, Brian H Stirm, Paul B Shepson)

154 Modeling ecosystem-level carbon fluxes using an advanced land surface model (FAPIS) coupled to the

Regional Atmospheric Modeling System (RAMS). (Jesse N Miller, Lianhong Gu, Wilfred M. Post) 155 Temporal Variations of Carbon Fluxes in a Temperate Forest Ecosystem of Northern Mexico (Jose de Jesus

Navar) 156 Canopy nitrogen, carbon assimilation and albedo in temperate and boreal forests: functional linkages and

potential climate feedbacks (Scott V Ollinger, Andrew D Richardson, David Y Hollinger, Mary E Martin, Peter B Reich, Lucie C Plourde, Steve Frolking)

157 Optimizing Large Scale Carbon Fluxes for North America (Andrew E. Schuh, A. Scott Denning, K. D. Corbin, M. Ulliasz, N. C. Parazoo)

158 The NOAA/ESRL tall tower and aircraft network: insights for the NACP and a vision for the future (Colm Sweeney, Arlyn E Andrews, Pieter Tans)

159 Bottom-up Scaling of Net Ecosystem Production and Net Biome Production over Oregon and California

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(David Turner, Beverly Law, Warren B. Cohen, David Ritts, Zhiqiang Yang, Tara Hudiburg, Maureen Duane) 160 Estimation of Evapotranspiration (ET) and Gross Primary Production (GPP) over North America (Wenping

Yuan, Shuguang Liu) 161 Steps towards the use of the Canadian CBM-CFS3 in Mexico (Bernardus de Jong, Marcela Olguin, Werner Kurz,

Leonel Iglesias, Armando Alanís) 162 Carbon stocks and emissions of Mexican forests and scrublands (Marcela Olguin, Bernardus H.J. de Jong,

Carlos Anaya, René Martinez, Omar Masera, Gabriela Guerrero) MCI Synthesis Posters (Thursday, February 19) 163 Impacts of leaf phenology and water table on interannual variability of region carbon fluxes in mixed

landscapes (Ankur R Desai, D Scott Mackay, Brent R Helliker, Paul R Moorcroft) 164 Carbon dioxide emissions in fallow periods of a corn-soybean rotation: eddy-covariance versus chamber

methods (Guillermo Hernandez-Ramirez, Timothy B Parkin, Jerry L. Hatfield, John Prueger, Tom J Sauer) 165 Spatial Variation of CO2 Fluxes Along Soil Transects in Corn and Soybean Canopies (Jerry L. Hatfield,

Timothy B Parkin, Tom J Sauer, John H Prueger, Guillermo Hernandez-Ramirez) 166 Modeling the Net Ecosystem Carbon Balance of agroecosystems of the Mid-Continent Intensive campaign

region during 2000-2005 (Roberto C. Izaurralde, Allison M. Thomson, Tris O. West, Wilfred M. Post, Jimmy R. Williams, David Manowitz, Daniel R. Chavas)

167 Simulation of carbon fluxes and prediction of crop yields within MCI region using SiBcrop (Erandathie Lokupitiya, Scott Denning, Keith Paustian, Kathy Corbin, Ian Baker, Kevin Shaefer, Matt Hansen, Kyle Pittman)

168 Observations and modeling results of regional-scale CO2 mixing ratio during the NACP’s MidContinent

Intensive (Natasha Miles, Scott Richardson, Kathy Corbin, Ian Baker, Eric Crosson, Kenneth J. Davis, Scott Denning)

169 Soil Carbon Budget over the U.S. Midwest Cropland (Zaitao Pan, Eugene S. Takle, Moti Segal, David Andrade) 170 Dynamics of below canopy nighttime CO2 profile measurements for corn and soybean (John H Prueger,

Timothy B Parkin, Jerry L. Hatfield, Tom J Sauer, Guillermo Hernandez-Ramirez, Tagir G Gilmanov) 171 Uncertainty in Modeled Agricultural C Stock Changes in the Mid-Continent Region (Shannon L Spencer,

Stephen Ogle) non-CO2 Synthesis Posters (Thursday, February 19) 172 Constraining the Terrestrial Carbon Cycle with Atmospheric Measurements of Carbonyl Sulfide (OCS)

(Joseph A Berry, Stephen A Montzka, J Elliott Campbell, S Randolph Kawa, Ian Baker, A Scott Denning, Sheri Conner- Gausephol, Adam Wolf)

173 Seasonal Variations in Methane Emissions from Central California (Chuanfeng Zhao, Arlyn E. Andrews, Janusz Eluszkiewicz, Adam I. Hirsch, Clinton MacDonald, Thomas Nehrkorn, Marc L. Fischer)

174 Soil methane and nitrous oxide dynamics as influenced by tillage and fertilizer management practices (Ermson Z. Nyakatawa, David A. Mays, Tom Way, Dexter Watts, David Smith, Allen Torbert)

175 Spatial and temporal patterns of CH4 and N2O fluxes between the atmosphere and terrestrial ecosystems

over North America (Hanqin Tian, Xiaofeng Xu, Guangsheng Chen, Mingliang Liu, Chaoqun Lu, Wei Ren, Chi Zhang)

176 Methane and carbon monoxide budgets for the Los Angeles area from September 2007 through June 2008.

(Debra Wunch, Paul O Wennberg, Geoffrey C Toon, Gretchen Keppel-Aleks, Yael G Yavin) Coastal Synthesis Posters (Thursday, February 19) 177 Seasonal evolution of carbon sources and sinks along the western continental margin of North America

(Simone Alin, Burke Hales, Peter Strutton)

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178 Is Lake Superior a net carbon source or sink? (Nazan Atilla, Galen A. McKinley, Valerie Bennington, Noel Urban, Nobuaki Kimura, Chin Wu, Ankur Desai)

179 Land to ocean carbon coupling between the Penobscot watershed and Gulf of Maine (William M Balch, George Aiken, Andrew Barnard, Thomas Huntington, Christina Orrico, Collin Roesler, Huije Xue)

180 Carbon Fluxes in the Gulf of Mexico – A report on the Ocean Carbon and Biogeochemistry Scoping Workshop on Terrestrial and Coastal Carbon Fluxes in the Gulf of Mexico; St. Petersburg, Florida, May 6-8,

2008 (Paula Coble, Lisa Robbins) 181 Riverine DOC Fluxes from the Northern Coastal Temperate Rainforest (Rick Edwards, Dave D'Amore, Eran

Hood, Frances Biles) 182 Carbon Cycle Simulations for the East Coast Continental Shelf of North America (Katja Fennel, Michael

Previdi, John Wilkin, Raymond Najjar) 183 U.S. Eastern Continental Shelf Carbon Cycling (USECoS): Modeling, Data Assimilation and Analysis

(Marjorie Friedrichs, Eileen Hofmann, Bronwyn Cahill, Katja Fennel, Dale Haidvogel, Kimberly Hyde, Cindy Lee, Antonio Mannino, Charles McClain, Ray Najjar, John O'Reilly, David Pollard, Sergio Signorini, John Wilkin, Jianhong Xue)

184 Advection of Salty low-Oxygen, low-pH Water onto the Continental Shelf from Baja California Mexico to San

Luis Obispo EUA (Jose Martin Hernandez, Richard A. Feely, Chirstopher L. Sabine, Debby Ianson, Burke Hales) 185 A biogeochemical/ecological model applied to the California Current System (Xin Jin, Nicolas Gruber, Curtis

Deutsch, Hartmut Frenzel, Scott C. Doney, Zouhair Lachkar, Damian Loher, James C. McWilliams, Takeyoshi Nagai, Gian-Kasper Plattner)

186 Variability of carbon sinks and fluxes in coastal ecosystems (Bror Fredrik Jonsson, Amala Mahadevan, Joseph Salisbury)

187 Use of the MICA System for Coastal CO2 Research (Xuewu Liu, Robert H Byrne, Lisa L Robbins, Paul Knorr, Geoffrey Lebon, Simone Alin, Richard A Feely)

188 Satellite Assessment of CO2 Distribution, Variability and Flux and Understanding of Control Mechanisms in a

River Dominated Ocean Margin (Steven E Lohrenz, Wei-Jun Cai) 189 Remineralization in the Mid-Atlantic Bight and the Gulf of Maine inferred from climatologies of dissolved

oxygen and primary production (Raymond Najjar, Jay O'Reilly) 190 Satellite Remote Sensing of Pigments, Absorption, and Primary Production in the Northeast U.S. Coast

(Xiaoju Pan, Antonio Mannino, Mary E Russ, Stanford B Hooker) 191 Direct measurement of CO2 fluxes from Lake Superior (Noel R. Urban, Judith A. Perlinger, Jennifer W. Mwangi,

Lucovic Bariteau, Chris W. Fairall) 192 Carbon Measurements in the Gulf of Maine (Douglas Vandemark, Joseph Salisbury, Chris Hunt, Shawn Shellito,

Robert Talbot, Ruth Varner, Wade McGillis, Christopher Sabine, Stacy Maenner) 193 The Effects of Land Use on Riverine CO2 Isotopic Signatures in the US Gulf Coast (Fanwei Zeng, Carrie A.

Masiello)

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Welcome / Opening Talks 1.A: Welcome

1.A: Welcome Peter Thornton, ORNL, thorntonpe@ornl.gov (Presenting) Peter Griffith, NACP Coordinator, peter.c.griffith@nasa.gov (Presenting) 1.B: NACP Update

1.B: NACP Update Paula Bontempi, NASA HQ, paula.s.bontempi@nasa.gov (Presenting) 1.C: NACP State-of-the-Science

1.C: NACP State-of-the-Science Kenneth J. Davis, Penn State University, davis@meteo.psu.edu (Presenting) Tony King, ORNL, kingaw@ornl.gov (Presenting) 1.D: Overview of the New Carbon Cycle Science Plan

1.D: Overview of the New Carbon Cycle Science Plan Chris Sabine, NOAA, chris.sabine@noaa.gov (Presenting) Anna Michalak, University of Michigan, amichala@umich.edu (Presenting)

Diagnosis/Attribution AM Talks2.A: The North American carbon cycle as seen from the atmospheric perspective: Recent progress from the NACP

2.A: The North American carbon cycle as seen from the atmospheric perspective: Recent progress from the NACP Scott Denning, Colorado State, denning@atmos.colostate.edu (Presenting) Arlyn Andrews, NOAA, arlyn.andrews@noaa.gov Martha Butler, Penn State, mpbutler@met.psu.edu Kathy Corbin, Colorado State, kdcorbin@atmos.colostate.edu Kenneth J. Davis, Penn State, davis@meteo.psu.edu Timothy Hilton, Penn State, hilton@meteo.psu.edu Andy Jacobson, NOAA, andy.jacobson@noaa.gov Anna Michalak, University of Michigan, amichala@umich.edu Natasha Miles, Penn State, nmiles@meteo.psu.edu Peter Rayner, Centre d'Energie Atomique, prayner@cea.fr Scott Richardson, Penn State, srichardson@psu.edu Andrew Schuh, Colorado State, aschuh@atmos.colostate.edu Thomas Lauvaux, Centre d'Energie Atomique, thomas.lauvaux@lsce.ipsl.fr Steven Wofsy, Harvard University, swofsy@seas.harvard.edu Atmospheric inversions are one of the primary tools being used to diagnose the carbon cycle of North America. Significant advances have been made in the observations, models and methodologies used to conduct these diagnostic studies. Advances include improved spatial resolution of atmospheric transport used in these studies, implementation of more advanced methods for data assimilation, more realistic prior terrestrial fluxes from improved land surface models, improved 'background' fluxes such as fossil fuel emission inventories, more extensive atmospheric CO2 observational networks, and increasing assimilation of complementary data including remote sensing and flux tower observations. Another important result is the establishment of a quasi-operational tool for interpreting atmospheric CO2 observations across North America, NOAA's Carbon Tracker. This talk will present a summary of progress in the development of atmospheric inversion studies of the North American carbon balance, drawing upon results from multiple research groups. Progress and challenges across groups will be summarized, with the goal of outlining the current state of the art in inversion studies, and the impact of the increase in continental data density that has occurred since 2000 until the present. Results to be summarized include progress towards the joint synthesis of mixing ratio and flux tower data, inversion results using an enhanced network of North American mixing ratio measurements on AmeriFlux towers, an inversion methodology that is independent of any biospheric model output as 'priors,' and is designed to provide an objective assessment of carbon flux variability as seen through the current sampling network, the third annual update of CarbonTracker which includes flux estimates through the end of 2007, and incorporates observations from seven new measurement sites, and high resolution continental (40km) and regional (10km) inversions conducted using the SiB/RAMS modeling system and a Lagrangian particle dispersion model, and maximum likelihood ensemble Kalman filtering. Keywords: Diagnosis

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2.B: Nested Inversion of the North America Carbon Flux with Forest Stand Age and 13C Constraints

2.B: Nested Inversion of the North America Carbon Flux with Forest Stand Age and 13C Constraints Jing M Chen, University of Toronto, chenj@geog.utoronto.ca (Presenting) Feng Deng, University of Toronto, dengf@geog.utoronto.ca Gang Mo, University of Toronto, gangmo@geog.uotoronto.ca Mustapha El Maayar, University of Toronto, elmaayarm@geog.utoronto.ca Misa Ishizawa, Environment Canada, ishizawa@ec.gc.ca Douglas Chan, Environment Canada, douglas.chan@ec.gc.ca Yude Pan, US Forest Service, ypan@fs.fed.us Richard Birdsey, US Forest Serivce, rbirdsey@fs.fed.us Kevin McCullough, US Forest Service, kevinmcculough@fs.fed.us Michael Sprintsin, University of Toronto, sprinstinm@geog.uotoronto.ca On the basis of our previous inversion using GlobalView CO2 data for 30 regions of the North America and 20 regions for the rest of the globe, we will improve the inversion results through additional constraints using a forest stand age map of the USA and Canada and GlobalView 13C data. The first version of this age map has been produced through a collaborative effort. It is demonstrated through our ecosystem modeling that the forest carbon source and sink distribution is closely related to forest stand age, and this source of information would be useful for constraining the CO2 flux inversion for the 30 sub-continental regions. The main purpose of using 13C data in our inversion is to differentiate between ocean and land fluxes. However, we are also exploring the information content of 13C data for separating terrestrial photosynthesis and respiration fluxes in different seasons. For this purpose, we have developed a process-based ecosystem model for estimating 13C discriminations during photosynthesis and respiration for C3 and C4 plants. Global distributions of 13C pools associated with various carbon pools in soil have been estimated for the purpose of estimating the 13C flux through heterotrophic respiration. In this presentation, the potential improvements in the North America carbon flux estimation using these two additional constraints will be discussed. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 2.C: The European Carbon balance by atmospheric and terrestrial measurements: An update of the dual constraint approach to derive a continental C-balance

2.C: The European Carbon balance by atmospheric and terrestrial measurements: An update of the dual constraint approach to derive a continental C-balance Ernst-Detlef Schulze, MPI, dschulze@bgc-jena.mpg.de (Presenting) Philippe Ciais, Laboratoire des Sciences du Climat, + et de l'Environnement,, philippe.ciais@cea.fr Sebastiaan Luyssaert, Universiteit Antwerpen, sebastiaan.luyssaert@ua.ac.be Jean-Francois Soussana, Grassland Ecosystem Research, jean-francois.soussana@clermont.fr Pete Smith, Institute of Biological and Environmental Science, pete.smith@abdn.ac.uk Martin Heimann, MPI, martin.heimann@bgc-jena.mpg.de Ivan Janssens, University of Antwerp, ivan.janssens@ua.ac.be MPI Biogeochemistry, Jena, Germany This paper will present the latest estimates of an European Carbon balance based on top-down atmospheric and bottom-up terrestrial measurements. Both methods indicate an increase in the European terrestrial carbon sink since 2003, but the uncertainties remain high. In 2003 Janssens estimated that the terrestrial sink was 205 Tg/yr (top down approach) and 111 Tg/yr (bottom up approach). In 2008 we estimate that the terrestrial sink is 350 Tg/yr (top down) and 253 Tg/yr (bottom up). For unknown reasons the atmospheric top-down approach remains systematically higher than the inventory based bottom-up estimates. The presentation will also show the partial fluxes from forests, grasslands, croplands and land-use change, and the problems associated with these estimates based on flow charts of gross primary productivity, net primary productivity, net biome productivity and associated respiration rates. The ratio of soil NBP/GPP is 2% in forest, 5% in grassland and -1% in croplands. In fact, in the long-term, grasslands sequester more C than forests. The presentation will contemplate about the design of observational networks. Keywords: Diagnosis, Regional/Continental Synthesis

Diagnosis/Attribution PM Talks3.A: Observing and Modelling the Carbon Cycle of Northern Forests

3.A: Observing and Modelling the Carbon Cycle of Northern Forests Hank A Margolis, Laval University, hank.margolis@sbf.ulaval.ca (Presenting) Robert F. Grant, University of Alberta, Robert.Grant@ualberta.ca The North American Carbon Program and the Canadian Carbon Program have provided a productive framework for building collaborative science partnerships between the US and Canada on the carbon cycle of northern forests for regional analyses. In 2002, Canadian and US scientists worked together to establish an east-west continental-scale transect of approximately 30 flux towers that encompasses many of Canada’s important northern forest ecoregions and disturbance regimes. These towers are now complemented by high-precision atmospheric concentration measurements at several sites. This northern flux tower network has contributed to the development of the scientific concepts, tools, data bases, models, and decision support capabilities required to build an integrated carbon observation and prediction system. The influence of forest harvest, fires, insects, and nutrient addition are being studied and the multi-year records along chronsequences in different regions permit us to extrapolate our results to regional, national and continental scales as well as to propose strategies for integrating inter-annual climate variability into an inventory-based forest carbon accounting system. Combining process models and field measurements, the CCP has provided new insights into the effects of climate and disturbance on forest carbon exchange, particularly during forest regeneration

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following fire or clearcutting and during regional warming and drought caused by continental-scale changes in weather patterns. We have also developed a robust collaboration on the development of satellite remote sensing tools for monitoring forest physiology and structure at large spatial scales. Finally, our participation in global synthesis efforts have allowed our data sets to contribute to circumpolar and global scale syntheses. Keywords: Diagnosis, Attribution, Prediction, Decision Support, Site-level Synthesis, Regional/Continental Synthesis 3.B: Improved understanding of the impacts of disturbance on the carbon cycle of the NA boreal forest and Western NA - integration of observations from field studies and analysis of remote sensing data into process-based models

3.B: Improved understanding of the impacts of disturbance on the carbon cycle of the NA boreal forest and Western NA - integration of observations from field studies and analysis of remote sensing data into process-based models Eric S. Kasischke, University of Maryland, ekasisch@umd.edu (Presenting) A. David McGuire, University of Alaska, ffadm@uaf.edu Merritt R. Turetsky, Michigan State University, mrt@uoguelph.ca Jennifer H. Harden, U.S. Geological Survey, jharden@usgs.gov Nancy H.F. French, Michigan Tech Research Institute, nancy.french@mtu.edu Laura L. Bourgeau-Chavez, Michigan Tech Research Institute, laura.chavez@mtu.edu Jill F. Johnstone, University of Alaska, jill.johnstone@usask.ca S. Yi, University of Alaska, ffsy@uaf.edu Elizabeth Hoy, University of Maryland, elizabeth.hoy@gmail.com Alex Schmid, University of Maryland, ajschmid@umd.edu Aditi Shenoy, University of Alaska, aditia.shenoy@gmail.com Matthew Borr, University of Maryland, mborr@umd.edu Tatiana Loboda, University of Maryland, tloboda@hermes.geog.umd.edu Kirsten Barrett, U.S. Geological Survey, kirstenne@gmail.com Roger D Ottmar, U.S. Forest Service, rottmar@fs.fed.us Kristen Manies, U.S. Geological Survey, kmanies@usgs.gov Knut Keilland, University of Alaska, ffkk@uaf.edu William de Groot, Canadian Forest Service, bdegroot@nrcan.gc.ca Evan S. Kane, Michigan State University, kanne@msu.edu Mike Waddington, McMaster University, wadding@mcmaster.ca Mike Flannigan, Canadian Forest Service, mike.flannigan@nrcan.gc.ca Werner Kurz, Canadian Forest Service, wkurz@pfc.cfs.nrcan.gc.ca Ron Hall, Canadian Forest Service, rhall@nrcan.gc.ca Claire Treat, Michigan State University, treatc@msu.edu Brian Benscoter, Michigan State University, benscot1@msu.edu Daniel J. Hayes, University of Alaska, ffdjh1@uaf.edu (Presenting) David W. Kicklighter, Marine Biological Laboratory, dkick@mlb.edu Kevin R. Gurney, Purdue University, kgurney@purdue.edu Todd J. Burnside, University of Alaska, canoebum@gmail.edu Jerry M. Melillo, Marine Biological Laboratory, jmelillo@umd.edu Don McKenzie, U.S. Forest Service, donaldmckenzie@fs.fed.us Fengming Yuan, University of Alaska, fffy@uaf.edu Research on how disturbance from fires and insects impact the terrestrial carbon budget in high Northern Latitude regions as well as the western, conterminous U.S. is being carried out through a series of inter-related NACP projects sponsored by NASA, USDA, and USGS, and through collaboration with Canadian researchers. This research involves collection and analyzing data from a variety of sources, including forest inventories, historical disturbance records, field studies designed to quantify the impacts of disturbance, and analysis of geospatial data, including that collected by a number of land-surface satellite remote sensing systems. The results from these studies are being used to modify process-based models to better understand the impacts of disturbance on the terrestrial carbon budget and direct carbon emissions from fires. In particular, these studies have shown: (a) the depth of burning of deep organic soils and peatlands common in the boreal forest region is much greater than previously thought, which (b) leads to a much higher direct emission of carbon-based gases into the atmosphere from boreal fires; (c) patterns of burning within individual fire events are controlled by vegetation cover, topography, and seasonal variations in climate; (d) variations in post-fire succession in black spruce forests are controlled by fire severity and site moisture conditions; and (e) that depth of the organic layer strongly controls soil temperature and moisture both pre-fire and post-fire. Our modeling studies have been focused in two areas: (a) the impacts of variation in depth of burning on the formation of permafrost; and (b) using a process-based biogeochemistry model, assessing how recent changes in atmospheric chemistry, climate trends, disturbance regimes, land use and management systems have affected recent trends in the carbon balance of North American arctic and boreal ecosystems. The results of the simulations suggest a shift in direction of the net flux from the terrestrial sink of earlier decades to a net source on the order of 27.5 Tg C per year between 1997 and 2006. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 3.C: Carbon Measurements along the North American Continental Margins

3.C: Carbon Measurements along the North American Continental Margins Christopher L. Sabine, NOAA/PMEL, chris.sabine@noaa.gov (Presenting) Richard A. Feely, NOAA/PMEL, richard.a.feely@noaa.gov Simone R. Alin, NOAA/PMEL, Simone.r.Alin@noaa.gov J. Martin Hernandez-Ayon, Universidad Autonoma de Baja California, jmartin@uabc.mx Debby Ianson, Fisheries and Oceans Canada, debby.ianson@dfo-mpo.qc.ca Burke Hales, Oregon State University, bhales@coas.oregonstate.edu Peter Strutton, Oregon State University, strutton@coas.oregonstate.edu Rik Wanninkhof, NOAA/AOML, rik.wanninkhof@noaa.gov

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Tsung-Hung Peng, NOAA/AOML, tsung-hung.peng@noaa.gov Doug Vandemark, University of New Hampshire, doug.vandemark@unh.edu Joe Salisbury, University of New Hampshire, joe.salisbury@unh.edu Wei-Jun Cai, University of Georgia, wcai@uga.edu Chris Langdon, University of Miami, clangdon@rsmas.miami.edu Stacy Maenner, NOAA/PMEL, stacy.maenner@noaa.gov Sylvia Musielewicz, NOAA/PMEL, sylvia.Musielewicz@noaa.gov The recent State of the Carbon Cycle Report synthesized historical CO2 measurements in North American coastal waters and found a near-neutral flux, but this was the result of a large high latitude sink canceled by a large low-latitude source. Neither of these regions, however, was adequately constrained by observations. As such, the air-sea exchange fluxes of CO2 along the continental margins of North America are still poorly understood and the net CO2 sink remains uncertain. In order to better understand carbon cycling in North American coastal waters, we conducted two large-scale coastal cruises, covering the Pacific, Atlantic, and Gulf coasts of North America during the summer of 2007. Collectively, the two cruises occupied 201 stations along the three coasts on 22 transects orthogonal to the coastline. The NACP West Coast Cruise extended from British Columbia to Baja Mexico in May–June 2007. The Gulf of Mexico and East Coast Carbon Cruise (GOMECC) ran from Texas to Maine in July–August 2007. We have also enhanced the surface ocean pCO2 observational network by adding instruments to volunteer observing ships (VOS) and moorings in coastal waters. Three core ships have been outfitted for the Pacific coast, four ships on the Atlantic coast, and one system has been installed on a ship that primarily works in the Gulf of Mexico. In addition, four moored pCO2 systems in the Atlantic and Pacific coastal waters has helped identify surface water pCO2 variability over a range of time-scales. We will review the data coming from these new platforms and the contributions they are making towards improving our understanding of carbon cycling on the North American continental margins. Keywords: Diagnosis, Coastal Synthesis 3.D: High resolution fossil fuel carbon emissions: progress, status and application to North American Carbon Cycle research

3.D: High resolution fossil fuel carbon emissions: progress, status and application to North American Carbon Cycle research Kevin Gurney, Purdue University, kgurney@purdue.edu (Presenting) Robert Andres, CDIAC, andresrj@ornl.gov As the single largest net flux of carbon between the land and atmosphere, fossil fuel CO2 flux remains a key component of research into understanding the North American carbon budget. Estimation of fossil fuel CO2 emissions has a long history at the national level and subsequent downscaling via population density. In recent years, research has begun to downscale from national level statistics using a variety of techniques with particular focus on the North American region. Downscaling has been approached from two complementary perspectives: a fuel supply (top-down) and a fuel combustion (bottom-up) approach. Here we report results and ongoing directions taken by these approaches, highlighting their applicability to carbon cycle research and their potential for integration and complemetarity. Researchers at Purdue University in collaboration with Colorado State University and Lawrence Berkeley National Laboratory have built the Vulcan inventory. This approach has leveraged information contained within the USEPA’s National Emissions Inventory for the assessment of nationally regulated air pollution. By utilizing the inventory emissions of CO and NOx combined with technology-specific emission factors, Vulcan has estimated 2002 CO2 emissions for industrial point sources, powerplants, mobile sources, residential and commercial sectors with information on fuel and combustion category. By utilizing additional data, estimation is quantified at a mixture of scales including geocoded points (power production, industrial, airport) roadways (onroad mobile), and census tract (residential, commercial, nonroad). Temporal resolution also represents a mixture from hourly (power production, mobile) to monthly (residential, commercial, nonroad, aircraft). Researchers at Oak Ridge National Laboratory have utilized data from the U.S. Energy Information Agency, Canadian and Mexican statistical offices and energy producers to quantify CO2 emissions at the state/province and monthly level for the years 1950 to the present. This approach has been applied to gas, liquid and solid fuel categories and includes both mass and stable isotope analysis. Gas flaring and CO2 emissions from cement manufacture have not been similarly treated due to the paucity of monthly data. A primary result of this work has been to show that there are significant statistical differences in month-to-month emission variations from a flat 1/12 distribution over a given year. Two other studies will be noted in this presentation, aimed at individual urban environments and sectors, highlighting the breadth of work ongoing in the fossil fuel carbon emissions research arena. All of these studies have uncovered aspects of fossil fuel carbon diagnosis, attribution and decision support and constitute an integration of carbon science, engineering, economics and demography. We will present the substantive results from these studies, their respective scales, evaluation and carbon cycle implications for NACP activities. Keywords: Diagnosis, Attribution, Decision Support, Regional/Continental Synthesis, MCI Synthesis

Site Interim Synthesis Talks4.A: Site-level synthesis of modeled and measured carbon, water, and energy fluxes across North America: Evaluation of model and measurement uncertainty

4.A: Site-level synthesis of modeled and measured carbon, water, and energy fluxes across North America: Evaluation of model and measurement uncertainty Deb Agarwal, UC Berkeley / Lawrence Berkeley National Lab, daagarwal@lbl.gov Brian Amiro, U Manitoba, brian.amiro@umanitoba.ca Ryan Anderson, U Montana, ryan.anderson@ntsg.umt.edu Altaf M. Arain, McMaster U, arainm@mcmaster.ca Ian Baker, Colorado State U, baker@atmos.colostate.edu Dennis Baldocchi, UC Berkeley, baldocchi@nature.berkeley.edu Alan Barr, Environment Canada, alan.barr@ec.gc.ca Andy Black, U British Columbia, andrew.black@ubc.ca Tom Boden, Oak Ridge National Lab, bodenta@ornl.gov

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Paul Bolstad, U Minnesota, pbolstad@umn.edu Sean Burns, National Center for Atmospheric Research, sean@ucar.edu Steve Campbell, Oak Ridge National Lab, campbellsl1@ornl.gov Guangsheng Chen, Auburn U, chengu1@auburn.edu Jing Chen, U Toronto, chenj@geog.utoronto.ca Philippe Ciais, LSCE, philippe.ciais@lsce.ipsl.fr Bob Cook, Oak Ridge National Lab, cookrb@ornl.gov David Cook, Argonne National Lab, drcook@anl.gov Peter Curtis, Ohio State U, curtis.7@osu.edu Kenneth J. Davis, Penn State U, davis@meteo.psu.edu Steve Delgrosso, Colorado State U, delgro@warnercnr.colostate.edu Michael Dietze, U Illinois Urbana-Champaign, mdietze@life.uiuc.edu Dimitre Dimitrov, U of Alberta, dimitre@ualberta.ca Danilo Dragoni, Indiana U, ddragoni@indiana.edu Howard Epstein, U Virginia, hee2b@virginia.edu Matthias Falk, UC Davis, mfalk@cstars.ucdavis.edu Marc Fischer, Lawrence Berkeley National lab, mlfischer@lbl.gov Larry Flanagan, U Lethbridge, larry.flanagan@uleth.ca Allen Goldstein, UC Berkeley, ahg@nature.berkeley.edu Michael Goulden, UC Irvine, mgoulden@uci.edu Robert F. Grant, U Alberta, robert.grant@afhe.ualberta.ca Lianhong Gu, Oak Ridge National Lab, lianhong-gu@ornl.gov Niall Hanan, Colorado State U, niall@nrel.colostate.edu Iain Hawthorne, U British Columbia, ihawth81@interchange.ubc.ca Tim Hilton, Pennsylvania State U, hilton@meteo.psu.edu Forrest Hoffman, Oak Ridge National Lab, forrest@climatemodeling.org David Hollinger, U New Hampshire, davidh@hypatia.unh.edu Tara Hudiburg, Oregon State U, tara.hudiburg@oregonstate.edu Misa Ishizawa, Environment Canada, misa.ishizawa@ec.gc.ca Cesar Izaurralde, Pacific Northwest National Lab, cesar.izaurralde@pnl.gov Jeff Nichols, Oak Ridge National Lab, n3j@ornl.gov Robin Kelly, Colorado State U, robinhk@nrel.colostate.edu Tony King, Oak Ridge National Lab, kingaw@ornl.gov Christopher Kucharik, U Wisconsin, kucharik@wisc.edu Peter Lafleur, Trent U, plafleur@trentu.ca Beverly Law, Oregon State U, bev.law@oregonstate.edu Zhengpeng Li, ARTS, zli@usgs.gov Leo Liu, USGS, sliu@usgs.gov Mingliang Liu, Auburn U, liuming@auburn.edu Erandi Lokupitiya, Colorado State U, erandi@atmos.colostate.edu Yiqi Luo, U Oklahoma, yluo@ou.edu Hank Margolis, Laval U, hank.margolis@sbf.ulaval.ca Roser Matamala, Argonne National Lab, matamala@anl.gov Harry McCaughey, Queen's U, mccaughe@post.queensu.ca Tilden Meyers, NOAA, tilden.meyers@noaa.gov Russell Monson, U Colorado, Boulder, monsonr@colorado.edu Bill Munger, Harvard U, jwmunger@seas.harvard.edu Walt Oechel, San Diego State U, oechel@sunstroke.sdsu.edu Ram Oren, Duke U, ramoren@duke.edu William Parton, Colorado State U, billp@nrel.colostate.edu Elizabeth Pattey, Agriculture and Agri-Food Canada, patteye@agr.gc.ca Changhui Peng, U Quebec, Montreal, peng.changhui@uqam.ca Philippe Peylin, LSCE, philippe.peylin@lsce.ipsl.fr ShiLong Piao, LSCE, shilong.piao@lsce.ipsl.fr Mac Post, Oak Ridge National Lab, wmp@ornl.gov Ben Poulter, PIK, ben.poulter@pik-potsdam.de David Price, Natural Resources Canada, dprice@nrcan.gc.ca Brett Raczka, Pennsylvania State U, bmr205@psu.edu Dan Ricciuto, Oak Ridge National Lab, ricciutodm@ornl.gov Andrew Richardson, U New Hampshire, andrew.richardson@unh.edu William J. Riley, Lawrence Berkeley National Lab, wjriley@lbl.gov Michael Ryan, Colorado State U, mryan@lamar.colostate.edu Alok Sahoo, Center for Research on Environment and Water, aksahoo2004@gmail.com Nick Saliendra, USFS, nsaliendra@fs.fed.us Crystal Schaaf, Boston U, schaaf@bu.edu Kevin Schaefer, National Snow and Ice Data Center, kevin.schaefer@nsidc.org Andrew Schuh, Colorado State U, aschuh@atmos.colostate.edu Michael Sprintsin, U Toronto, misprin@gmail.com Paul Stoy, U Edinborough, paul.stoy@ed.ac.uk Peter Thornton, Oak Ridge National Lab, thorntonpe@ornl.gov (Presenting) Hanqin Tian, Auburn U, tianhan@auburn.edu Christina Tonitto, Cornell U, ct244@cornell.edu Margaret Torn, Lawrence Berkeley National Lab, mstorn@lbl.gov Catharine van Ingen, Microsoft, vaningen@microsoft.com Rodrigo Vargas, UC Berkeley, rvargas@nature.berkeley.edu

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Hans Verbeeck, Ghent U, hans.verbeeck@ugent.be Shashi Verma, U Nebraska, Lincoln, sverma1@unl.edu Nicolas Viovy, LSCE, nicolas.viovy@lsce.ipsl.fr Weile Wang, NASA Ames, weile.wang@gmail.com Ensheng Weng, U Oklahoma, esweng@ou.edu Christopher Williams, Clark U, cwilliams@clarku.edu Xiaofeng Xu, Auburn U, xuxiaof@auburn.edu Bai Yang, Oak Rdge National Lab, yangb@ornl.gov Wenping Yuan, National Research Council, wyuan@usgs.gov Tianshan Zha, Environment Canada, tianshan.zha@ec.gc.ca Xuhui Zhou, U Oklahoma, zxuhui14@ou.edu Long-term interactions and feedbacks between the terrestrial carbon cycle and the global climate system depend on the integrated dynamics of carbon stocks and fluxes at continental scales. The tremendous geographic and biological diversity of the North American continent results in a very challenging spatial scaling problem as we try to understand the integrated continental carbon cycle and carbon-climate dynamics. Large-scale modeling is an essential tool in generating integrated analyses of these dynamics, but there is an increasing call from the assessment and climate policy communities for a quantification of uncertainty associated with large-scale estimates of carbon and carbon-climate interactions. We are addressing that need by performing a detailed evaluation of modeled and observed carbon stocks and fluxes across a wide range of North American vegetation types and climate zones, focusing explicitly on the problem of uncertainty estimation in both observations and model results. Our synthesis team includes researchers representing 36 individual sites where eddy covariance and other meteorological measurements have been made for multiple years, supplemented with detailed biological measurements necessary for model parameterization and evaluation. The modeling team includes researchers representing 15 models of varying intents and complexity. Care has been taken to develop consistent datasets and a well-defined simulation protocol, to control as much as possible the external contributions to uncertainty. Here we present within-model and between-model uncertainty estimates, in comparison to the associated observational uncertainties. The analysis is designed to answer the question: “Are the modeled and observed carbon fluxes and stocks the same, within the bounds of uncertainty – and if not, why?” We identify and quantify the main contributions to modeled and measurement uncertainty. These include, for the models, input surface weather data and representation of disturbance history, and, for the measurements, assumptions related to partitioning of net carbon flux into photosynthesis and respiration components, and data filtering and gap-filling methodologies. Keywords: Site-level Synthesis 4.B: Regional to Continental Upscaling of AmeriFlux Data for Carbon Cycle Studies: Progress, Challenges, and New Directions

4.B: Regional to Continental Upscaling of AmeriFlux Data for Carbon Cycle Studies: Progress, Challenges, and New Directions Jingfeng Xiao, Penn State, jing@psu.edu (Presenting) Kenneth J. Davis, Penn State, davis@meteo.psu.edu Xuhui Zhou, zxuhui14@gmail.com,, university of oklahoma Tao Zhou, tzhou@bnu.edu.cn,, beijing normal university Yiqi Luo, yluo@ou.edu,, university of oklahoma Christian Beer, cbeer@bgc-jena.mpg.de,, max planck institute for biogeochemistry Ben Bond-Lamberty, bondlamberty@pnl.gov,, university of maryland/pnnl Ankur Desai, desai@aos.wisc.edu,, university of wisconsin, madison Martin Jung, mjung@bgc-jena.mpg.de,, max planck institute for biogeochemistry Beverly E. Law, bev.law@oregonstate.edu,, oregon state university Leo Liu, sliu@usgs.gov,, usgs eros Wilfred M. Post, ORNL, wmp@ornl.gov Markus Reichstein, markus.reichstein@bgc-jena.mpg.de,, max planck institute for biogeochemistry Daniel Ricciuto, ricciutodm@ornl.gov,, oak ridge national laboratory Enrico Tomelleri, etomell@bgc-jena.mpg.de,, max planck institute for biogeochemistry David Turner, david.turner@oregonstate.edu,, oregon state university Steven C. Wofsy, Harvard University, swofsy@seas.harvard.edu Bruce K. Wylie, wylie@usgs.gov,, usgs eros Xiangming Xiao, xiangming.xiao@ou.edu,, university of oklahoma Feihua Yang, feihuayang@wisc.edu,, university of wisconsin, madison Li Zhang, lizhang@ceode.ac.cn,, center for earth observation and digital Maosheng Zhao, zhao@ntsg.umt.edu,, university of montana The AmeriFlux network provides continuous observations of ecosystem level exchange of CO2 spanning diurnal, synoptic, seasonal, and interannual time scales. AmeriFlux towers are distributed across North America, Central America, and South America, and involve a wide variety of ecosystem and climate types. However, these flux measurements only represent the carbon fluxes at the scale of the tower footprint, ranging from a few hundred m2 to a few km2. Diagnoses of regional or continental scale fluxes are needed in order to quantify carbon budgets and examine climate impacts and climate policy issues over these large areas. Advances have been made in the upscaling of eddy flux data at regional to continental scales. Here we will review the different approaches for the upscaling of eddy flux data (e.g., machine learning methods, light use efficiency models, empirical carbon models, and process-based biogeochemical models) and the quantification of carbon flux uncertainties, the progress made to date, and the implications of our results for the attribution and prediction of regional to continental scale fluxes. We will also briefly discuss the strengths, weaknesses, and problems of the upscaling of AmeriFlux data in carbon cycling studies in comparison to alternative approaches (e.g., atmospheric inverse models, inventory approaches, model simulations). Finally, we will review current efforts to upscale AmeriFlux data and the progress and challenges expected in the near future. Keywords: Diagnosis, Attribution, Site-level Synthesis, Regional/Continental Synthesis

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MCI Interim Synthesis Talks5.A: Synthesis of Tower CO2 Flux Observations in Key Agricultural Ecosystems in the MCI Region

5.A: Synthesis of Tower CO2 Flux Observations in Key Agricultural Ecosystems in the MCI Region S. B. Verma, University of Nebraska, sverma1@unl.edu (Presenting) A. E. Suyker, University of Nebraska, asuyker1@unl.edu J. M. Baker, USDA-ARS, jbaker@umn.edu J. L. Hatfield, National Soil Tilth Laboratory, hatfield@nstl.gov T. P. Meyers, NOAA/ARL/ATDD, tilden.meyers@noaa.gov C. J. Bernacchi, Illinois State Water Survey, bernacch@uiuc.edu T. J. Griffis, University of Minnesota, tgriffis@umn.edu H. Yang, University of Nebraska, hyang2@unl.edu T. Setiyono, University of Nebraska, tsetiyono2@unl.edu E. Lokupitiya, Colorado State University, erandi@kiwi.atmos.colostate.edu We have recently initiated a synthesis of CO2 flux measurements made at tower flux sites planted in maize and soybean at Ames, IA; Bondville, IL; Mead, NE; and Rosemount, MN. At the next NACP All-Investigators Meeting, we propose to present a detailed comparison of magnitudes and seasonal distributions of net ecosystem CO2 production (NEP), gross primary productivity (GPP), and ecosystem respiration (Re). Role of selected controlling factors will be examined on daily GPP at several stages of crop growth. Seasonally integrated GPP calculated from the measurements at the four sites will also be investigated. Relationship between daily and seasonally integrated Re and GPP for maize and soybean will be presented. Keywords: Attribution, MCI Synthesis 5.B: Inventory-based CO2 Budget for the MCI Interim Synthesis: Progress and Preliminary Results

5.B: Inventory-based CO2 Budget for the MCI Interim Synthesis: Progress and Preliminary Results Tristram O West, Oak Ridge National Laboratory, westto@ornl.gov (Presenting) Stephen M Ogle, Colorado State University, ogle@nrel.colostate.edu Objectives of the Mid-Continental Intensive Campaign (MCI) include the development, evaluation, and comparison of top-down atmospheric budgets and bottom-up inventory budgets. Improvements in both methods are expected through the evaluation of mechanisms governing CO2 fluxes in each approach. An interim synthesis for 2000-2005 is currently underway, combining results across multiple projects funded through the NACP. This initial effort will help guide the final synthesis for years 2007-2008. The CO2 flux inventory for the MCI region consists of all substantial carbon sources and sinks, including soil and plant carbon changes, fossil emissions, livestock and human emissions, and other emissions due to land management (e.g., lime application and cropland production inputs). Soil carbon and plant biomass changes will be estimated for cropland, grassland, and forest ecosystems. Total net carbon flux for the MCI region will be presented, along with individual flux contributions and associated uncertainty. Inventory estimates with multiple investigator contributions (e.g., soil carbon) will be compared and contrasted. Key NACP research questions will be addressed using preliminary results from the MCI inventory, particularly diagnosis of the carbon balance in North America. Keywords: Diagnosis, Attribution, MCI Synthesis 5.C: Resolving CO2 Flux Estimates from Atmospheric Inversions and Inventories in the Mid-Continent Region

5.C: Resolving CO2 Flux Estimates from Atmospheric Inversions and Inventories in the Mid-Continent Region Stephen M. Ogle, Colorado State University, ogle@nrel.colostate.edu (Presenting) Dan Cooley, Colorado State University, cooleyd@stat.colostate.edu Scott Denning, Colorado State University, denning@atmos.colostate.edu Kenneth J. Davis, Pennsylvania State University, davis@met.psu.edu Tristram West, Oak Ridge National Laboratories, westto@ornl.gov F. Jay Breidt, Colorado State University, jbreidt@stat.colostate.edu Atmospheric inversions and inventories represent two lines of evidence on the carbon budget of regions, but these approaches often do not provide consistent results. Inversions rely on CO2 concentration measurements to infer fluxes between the terrestrial surface and atmosphere. Inventories are typically conducted using models to predict changes in C pools, or CO2 fluxes directly, based on various driving variables influencing uptake and release of CO2 from the terrestrial surface. Both of the approaches have their strengths and weaknesses, and one of the key objectives of the NACP Mid-Continent Intensive (MCI) is to reconcile differences in estimates between these approaches, to the extent possible. With data from multiple studies funded through NACP, an interim synthesis is underway to meet this objective. Inventories and inversions for 2000-05 are first compared to understand the consistencies and inconsistencies in results from the two approaches. This exploratory phase entails investigation via graphical tools, testing for spatial and temporal autocorrelations, and a regression analysis where the differences between the inventories and inversions are regressed against both inventory estimates and land-use characteristics. We then combine and reconcile the estimates by employing a hierarchical model where both sources of information will be utilized to construct a latent model of the true CO2 flux, providing regional fluxes and associated uncertainties. Results from the interim analysis will establish a benchmark for gauging the improvement in predictions of CO2 flux resulting from the MCI sampling campaign occurring during 2007-08. Overall, this study is anticipated to improve diagnosis of regional carbon fluxes, which is a key objective of the NACP. Keywords: Diagnosis, MCI Synthesis 5.D: NACP’s Mid-Continent Intensive: Atmospheric Results

5.D: NACP’s Mid-Continent Intensive: Atmospheric Results Natasha Miles, Penn State Univ, nmiles@met.psu.edu (Presenting)

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Arlyn Andrews, NOAA, arlyn.andrews@noaa.gov Kathy Corbin, Colorado State Univ, kdcorbin@atmos.colostate.edu Kenneth J. Davis, Penn State Univ, davis@met.psu.edu Scott Denning, Colorado State Univ, denning@atmos.colostate.edu Douglas Martins, Purdue Univ, dmarti18@purdue.edu Scott Richardson, Penn State Univ, srichardson@psu.edu Paul Shepson, Purdue Univ, pshepson@purdue.edu Colm Sweeney, NOAA, colm.sweeney@noaa.gov The Mid-Continent Intensive (MCI) Campaign is designed to test methods to measure the carbon flux between land surfaces and the atmosphere, in a region including Iowa and portions of surrounding states. The goals include evaluating and improving regional carbon flux estimates derived from “top-down” atmospheric budgets and “bottom-up” ecosystem inventories. In this talk, we focus on the atmospheric results, including tower, regional inversion, and aircraft results. Tower sites operational during the MCI campaign include the West Branch, IA, and Park Falls, WI, NOAA tall towers, five medium-height towers (“Ring 2”), and two surface-layer towers. The daily daytime average throughout the 2007 and 2008 growing seasons indicate a surprisingly large 50-ppm seasonal drawdown, with significant synoptic variability. At any particular daytime hour, the CO2 mixing ratio at the sites nearly always differs by more than 5 ppm, while at times the inter-site difference is as large as 30-50 ppm. Modeling efforts, using the coupled ecosystem-atmosphere model SiB3-RAMS, attempt to evaluate the cause of the observed large and variable gradients, and to test the coupled model’s ability to reproduce these gradients. Including a crop phenology model dramatically improves the modeled concentrations at all the towers, reducing the root mean square errors by nearly half. We are particularly interested in the effects of the flooding that occurred in the Midwestern U.S. due to heavy rainfall in June 2008, and aggravated by the unusually wet previous winter and spring seasons (NCDC, 2008). The observed CO2 uptake at the West Branch tall tower was only 40% of that for the same period in 2007. Comparisons are also made with Purdue University in-situ CO2 measurements on sinusoidal flights in and above the boundary layer, and NOAA flights with in-situ CO2 measurements. Keywords: Diagnosis, MCI Synthesis

Non-CO2/Greenhouse Gases Interim Synthesis Talks6.A: Interim non-CO2 greenhouse gases synthesis results

6.A: Interim non-CO2 greenhouse gases synthesis results Steve Wofsy, Harvard University, swofsy@seas.harvard.edu (Presenting)

Keywords: non-CO2 Greenhouse Gases Synthesis

Regional Interim Synthesis Talks7.A: North American Carbon Project (NACP) Spatial Model-Data Comparison Project (MDC) for Regional and Continental Synthesis

7.A: North American Carbon Project (NACP) Spatial Model-Data Comparison Project (MDC) for Regional and Continental Synthesis Wilfred M. Post, ORNL, wmp@ornl.gov (Presenting) Deborah N. Huntzinger, University of Michigan, dnhuntzi@umich.edu (Presenting) Andrew Jacobson, NOAA/ESRL, andy.jacobson@noaa.gov Robert B. Cook, ORNL, cookrb@ornl.gov Regional/Continental Interim-Synthesis Team Participants, Everywhere, postwmiii@ornl.gov Available observations are localized and widely separated in both space and time, so we depend heavily on models to characterize, understand, and predict carbon fluxes at regional or global scales. The results from each model differ because they use different approaches (forward vs. inverse), modeling strategies (detailed process, statistical, observation based), process representation, boundary conditions, initial conditions, and driver data. To investigate these differences we conducted a model-data comparison using available atmospheric inverse and forward ecosystem model output, and regional scale measurement data. Our analyses focused on the following 3 questions: 1. Do model results and observations show consistent spatial patterns in response to the 2002 drought? From measurements and model, can we infer what processes were affected by the 2002 drought? 2. What is the spatial pattern and magnitude of interannual variation in carbon sources and sinks? What are the components of carbon fluxes and pools that contribute to this variation? 3. What are the magnitudes and spatial distribution of carbon sources and sinks, and their uncertainties during the period 2000-2005? The progress to date includes identifying benchmark datasets and developing model-data comparison methods in order to identify the causes of differences. Inverse or top-down analyses provide estimates of carbon fluxes that are optimally consistent with atmospheric CO2 concentration measurements. Forward, or bottom-up ecosystem models are used to test hypotheses concerning the attribution of processes

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in determining carbon fluxes. Examining and comparing results of inverse and forward model simulations with each other and with suitable benchmark spatial measurements help evaluate model strengths/weaknesses and utility, thereby providing multiple views of spatial and temporal patterns of fluxes, leading to understandings of processes involved, providing an improved basis for making projections.

Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 7.B: Inverse Modeling

7.B: Inverse Modeling Andy Jacobson, NOAA Earth System Research Laboratory, andy.jacobson@noaa.gov (Presenting) Keywords: Regional/Continental Synthesis 7.C: The West Coast Regional Analysis

7.C: The West Coast Regional Analysis Beverly Elizabeth Law, Oregon State University, bev.law@oregonstate.edu (Presenting) Dave Turner, Oregon State University, david.turner@oregonstate.edu Mathias Goeckede, Oregon State University, mathias.goeckede@oregonstate.edu Warren B. Cohen, Oregon State University, warren.cohen@oregonstate.edu Maureen Duane, Oregon State University, maureen.duane@oregonstate.edu Dave Ritts, Oregon State University, david.ritts@oregonstate.edu Tara Hudiburg, Oregon State University, tara.hudiburg@oregonstate.edu Zhiqiang Yang, Oregon State University, zhiqiang.yang@oregonstate.edu Chris Potter, NASA Ames, cpotter@mail.arc.nasa.gov Robert E. Kennedy, Oregon State University, robert.kennedy@oregonstate.edu The objectives are to reduce uncertainty in understanding C sources and sinks, and to determine the effects of disturbance and variation in climate on the regional carbon balance of Oregon, Washington and California over the past 30 years. We combine a spatially nested hierarchy of observations with bottom-up (Biome-BGC) and top-down (WRF-STILT-CFLUX) modeling to estimate carbon stocks and fluxes over the region. Validation efforts include comparisons to forest inventory (USDA) based estimates of stocks and fluxes, tower fluxes, and those produced by alternative modeling approaches (e.g. CASA at relatively coarse spatial resolution). Inventory data show that in the absence of disturbance, Oregon and N CA could store twice as much carbon in forests if they were managed for carbon; although it would take hundreds of years to reach these levels in all ecoregions, land-based stocks could increase by 15% in 50 years. Live and dead biomass are usually higher on public lands, which are dominated by older forests. Decrease in NPP with age was not general across ecoregions, with no marked decline in old stands (>200 years) in some ecoregions (Hudiburg et al. 2008). Application of the top-down modeling approach, which extracts regionally representative atmospheric CO2 concentration time-series, highlights the strong spatial variability in CO2 exchange rates, and thus the uncertainties associated with extrapolating point mode flux observations into spatial maps. Fossil fuel emissions in CA were an order of magnitude higher than OR and WA emissions. Fire emissions were low compared to harvest removals. Net biome production (Biome-BGC summed NEP minus harvest removals and fire losses) was a much higher proportion of the CO2 equivalent of fossil fuel emissions in OR than in CA. Climate anomalies showed that the wide-spread drought in 2002-03 led to the lowest NEP over the whole region, and that NEP was highest in 2004 compared with the 10-year mean. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis

Coastal Interim Synthesis Talks8.A: Toward understanding of carbon fluxes in the coastal oceans: synthesis activities for the U.S. East Coast and the Gulf of Mexico

8.A: Toward understanding of carbon fluxes in the coastal oceans: synthesis activities for the U.S. East Coast and the Gulf of Mexico Steven Lohrenz, USM, Steven.Lohrenz@usm.edu (Presenting) Wei-Jun Cai, UGA, wcai@uga.edu Jim Bauer, VIMS, bauer@vims.edu Ron Benner, USC, benner@biol.sc.edu Tom Bianchi, TAMU, tbianchi@tamu.edu Elizabeth Boyer, ewb100@psu.edu, ewb100@psu.edu Fei Chai, University of Maine, fchai@maine.edu Paula Cobble, USF, pcoble@marine.usf.edu Katja Fennel, Dal Univ, Katja.Fennel@dal.ca Marjorie Friedrichs, VIMS, marjy@vims.edu Chuck Hopkinson, UGA, chopkins@uga.edu Brent McKee, UNC, bamckee@email.unc.edu Bill Miller, UGA, bmiller@UGA.EDU Ray Najjar, PSU, najjar@meteo.psu.edu Cindy Pilskaln, University of Massachusetts Dartmouth, cpilskaln@umassd.edu Peter Raymond, Yale, peter.raymond@yale.edu Lisa Robbins, USGS, lrobbins@usgs.gov Joe Salisbury, UNH, joe.salisbury@unh.edu Hanqin Tian, Auburn, tianhan@auburn.edu

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Doug Vandemark, UNH, doug.vandemark@unh.edu Penny Vlahos, UCONN, penny.vlahos@uconn.edu Jerry Wiggert, USM, jerry.wiggert@usm.edu Continental margins represent a key interface between continental and ocean carbon reservoirs. In the past few decades, there have been numerous research activities examining coastal ocean carbon cycling on the U.S. east and Gulf of Mexico coasts. These efforts have included large multiple investigator programs such as the Shelf-Edge Exchange Program (SEEP), Ocean Margins Program (OMP) in the Mid-Atlantic Bight and South Atlantic Bight, and the Nutrient Enhanced Coastal Ocean Productivity (NECOP) program in the Gulf of Mexico as well as numerous smaller research projects. Several current coastal ocean projects on the east and Gulf coasts are funded by federal agencies in support of or related to the North American Carbon Program (NACP) and Ocean Carbon and Biogeochemistry (OCB) program efforts. While abundant information is accumulating, there remains to be an effective assembly, synthesis, and modeling of past and current research findings to identify the diagnostic features (C budget, spatial and temporal variability, etc.), attributions (underlying control mechanisms and linkages), and prediction (predictive modeling) of carbon cycling in continental margins. In this presentation, we will review the existing data and current understanding of the role of coastal systems in global carbon cycles, including watershed and river fluxes of both organic and inorganic carbon, air-sea fluxes of CO2, coastal metabolic cycling of carbon and organic matter, and shelf-slope exchange processes. In addition, we will strive to identify key synthesis approaches, knowledge gaps, hypotheses, and future research priorities for continental margin carbon cycling and budgets. Keywords: Diagnosis, Attribution, Prediction, Coastal Synthesis 8.B: Recent (and Future) Advances in Carbon Cycle Synthesis along the North American Pacific Coast

8.B: Recent (and Future) Advances in Carbon Cycle Synthesis along the North American Pacific Coast Simone Alin, PMEL/NOAA, simone.r.alin@noaa.gov (Presenting) Andrew Dickson, Scripps Institution of Oceanography, adickson@ucsd.edu Wiley Evans, Oregon State University, wevans@coas.oregonstate.edu Richard Feely, PMEL/NOAA, richard.a.feely@noaa.gov Burke Hales, Oregon State University, bhales@coas.oregonstate.edu Martin Hernandez-Ayon, Universidad Autonoma de Baja California, jmartin@uabc.mx Debby Ianson, Institute of Ocean Sciences, Fisheries and Oceans Canada, iansond@pac.dfo-mpo.gc.ca Lauren Juranek, PMEL/NOAA, laurie.juranek@noaa.gov Carol Maloy, Washington Department of Ecology, cfal461@ecy.wa.gov Jan Newton, University of Washington, newton@apl.washington.edu Christopher Sabine, PMEL/NOAA, chris.sabine@noaa.gov Peter Strutton, Oregon State University, strutton@coas.oregonstate.edu Phillippe Tortell, University of British Columbia, ptortell@eos.ubc.ca Verena Tunnicliffe, University of Victoria, verenat@uvic.ca Bev Law, Oregon State University, Bev.Law@oregonstate.edu Since the preparation of the State of the Carbon Cycle Report (2007) and the North American Continental Margins report (2008), a number of advances have pushed large-scale carbon cycle synthesis efforts forward for the North American Pacific Coast. Regional to continent-scale hydrographic surveys, as well as moored and underway CO2 systems, have substantially improved the spatiotemporal coverage of inorganic carbon and related chemical and physical measurements along the Pacific Coast from British Columbia to Panama. In addition, methodological strides in synthesizing and extrapolating observed CO22 data across spatial and temporal dimensions, in conjunction with the use of remote sensing data products and self-organizing maps, have given us the ability to create seasonal maps of CO2 for the Pacific Coast south of British Columbia, thereby improving estimates of net annual air-sea CO2 fluxes. Other recent advances in coastal carbon cycle diagnosis and attribution include: 1) recent high-resolution observations of seasonal CO2 dynamics on the Oregon, Washington, and British Columbia continental shelves, 2) a new proxy method for reconstructing ocean acidification histories on continental shelves based on historical hydrographic data, and 3) improved estimates of primary production across the continental shelf using oxygen triple isotopes. These large-scale research and synthesis efforts by government and academic scientists have been funded by a variety of federal and state agencies in support of carbon cycle science goals (North American Carbon Program, Ocean Carbon and Biogeochemistry) or national/regional fisheries program goals (e.g. California Cooperative Oceanic Fisheries Investigations and Investigaciones Mexicanas de la Corriente de California). The NACP West Coast Interim Synthesis Working Group is being organized to incorporate these new data and approaches into future coastal carbon cycle syntheses and models. Keywords: Diagnosis, Attribution, Prediction, Coastal Synthesis 8.C: Diagnosing carbon dynamics in diverse ocean environments using in-situ optical and remotely- sensed data.

8.C: Diagnosing carbon dynamics in diverse ocean environments using in-situ optical and remotely- sensed data. Joe Salisbury, University of New Hampshire, joe.salisbury@unh.edu Amala Mahadevan, Boston University, amala@bu.edu Bror Jonsson, Princeton University, bror@bu.edu Doug Vandemark, University of New Hampshire, doug.vandemark@unh.edu (Presenting) Christopher Hunt, University of New Hampshire, chunt@unh.edu Huijie Xue, University of Maine, hxue@maine.edu The major goal of our research is to develop methodologies that will enable remotely sensed retrievals of surface dissolved inorganic carbon (DIC) status and its rate of change. We report on progress in three research efforts. The first describes relationships between in-water partial pressure of carbon dioxide (pCO2) and optical data in the complex coastal waters of the Gulf of Maine. Next, we examine the spatiotemporal variability of DIC, its rate of change, and the net production & export of phytoplankton carbon from a coastal system. By tracking satellite-derived particulate organic carbon stocks within a Lagrangian space-time frame with a circulation model, we diagnose the temporal variations in net community production (NCP) and export from a region. Based on field measurements, we develop relationships between in-water partial pressure of carbon dioxide (pCO2) and optically derived NCP estimates in the complex coastal waters of the Gulf of Maine. Finally, we describe preliminary efforts in retrieving basin-scale pCO2 using MODIS ocean color and SST satellite data. Satellite retrievals of DIC behavior are challenging because of the varying length & time scales of processes modulating DIC, as well as time lags between productivity and air-

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sea gas exchange. We submit that retrieval methods capable of tracking satellite data in time and space, and/or algorithms based within well-defined hydrographic or optical provinces will show the most promise. Keywords: Diagnosis, Coastal Synthesis

Prediction Talks 9.A: The 20th century carbon budget simulated with the CCCma earth system model CanESM1

9.A: The 20th century carbon budget simulated with the CCCma earth system model CanESM1 Vivek K Arora, Canadian Centre for Climate Modelling and Analysis, vivek.arora@ec.gc.ca (Presenting) George J Boer, Canadian Centre for Climate Modelling and Analysis, george.boer@ec.gc.ca Charles L Curry, Canadian Centre for Climate Modelling and Analysis, charles.curry@ec.gc.ca James R Christian, Canadian Centre for Climate Modelling and Analysis, jim.christian@ec.gc.ca Kos Zahariev, Canadian Centre for Climate Modelling and Analysis, kos.zahariev@ec.gc.ca Kenneth L Denman, Canadian Centre for Climate Modelling and Analysis, ken.denman@ec.gc.ca Gregory M Flato, Canadian Centre for Climate Modelling and Analysis, greg.flato@ec.gc.ca John F Scinocca, Canadian Centre for Climate Modelling and Analysis, john.scinocca@ec.gc.ca William J Merryfield, Canadian Centre for Climate Modelling and Analysis, bill.merryfield@ec.gc.ca The atmosphere-land-ocean CO2 exchange for the 1850-2000 period, as simulated with the Canadian Centre for Climate Modelling and Analysis Earth System Model (CanESM1), is assessed. Land use change (LUC) emissions are estimated interactively on the basis of changes in crop area. In its default configuration, the terrestrial CO2 uptake in the model is higher and atmospheric CO2 concentration lower than observed for the 1850-2000 period. This is likely due to lower simulated LUC emissions in the model because LUC due to changes in pasture area and forest harvesting are not taken into account, although LUC emissions are highly uncertain (± 50% uncertainty). Down-regulation of photosynthesis is observed in many experimental studies that grow plants at ambient and elevated CO2. However, the role of down-regulation of terrestrial photosynthesis in the carbon cycle has not yet been explored. We examine the effect of photosynthesis down-regulation by implementing an empirical down-regulation mechanism based on experimental studies of plant growth under conditions of increased CO2. The rate of increase of terrestrial net primary productivity with CO2 in the model, after down-regulation, is consistent with that inferred from an independent study. When down-regulation is implemented, the 20th century land and ocean carbon uptake and atmospheric CO2 concentration are in good agreement with observation-based estimates. Our results show that down-regulation of terrestrial photosynthesis may play a role in terrestrial carbon uptake similar in magnitude to the uncertainty in LUC emissions. The empirical approach used here also offers a reasonable method of implementing down-regulation for coupled carbon-climate simulations in the absence of a more explicit biogeochemical representation in models. Keywords: Attribution, Regional/Continental Synthesis 9.B: When is the Permafrost Carbon Tipping Point?

9.B: When is the Permafrost Carbon Tipping Point? Kevin M Schaefer, National Snow and Ice Data Center, kevin.schaefer@nsidc.org (Presenting) Tingjun Zhang, National Snow and Ice Data Center, tzhang@nsidc.org Lori Bruhwiler, NOAA Earth System Research Laboratory, lori.bruhwiler@noaa.gov Permafrost in the Arctic contains as much as 950 Gt of organic matter, frozen since the last ice age 20,000-30,000 years ago. As permafrost thaws in the 21st century, this organic matter will begin to decay, increasing atmospheric carbon dioxide and amplifying the warming rate, creating a positive permafrost carbon feedback on climate. The permafrost carbon tipping point occurs when respiration due to the decay of currently frozen organic matter overpowers enhanced plant uptake due to longer growing seasons, changing the Arctic from a carbon sink to a source. The permafrost carbon tipping point represents an abrupt change in high latitude carbon balance and signals the start of the permafrost carbon feedback. None of the coupled carbon-climate models used in the Fourth IPCC Assessment account for the permafrost carbon feedback in their projections of 21st century climate. We add permafrost carbon dynamics to the Simple Biosphere/Carnegie-Ames-Stanford Approach (SiBCASA) model and use the NCEP reanalysis as input weather. To represent future climate change, we scale the NCEP air temperature assuming a linear, 4 °C century-1 temperature increase in the Arctic between 2000 and 2100. Point simulations indicate that even a modest increase in active layer depth could result in local tipping points by the mid-21st century. We expand this analysis to the entire Arctic region and estimate the timing of the permafrost carbon tipping point and the potential strength of the permafrost carbon feedback in terms of the amount of carbon released into the atmosphere by 2100. Keywords: Diagnosis, Attribution, Prediction, Site-level Synthesis, Regional/Continental Synthesis 9.C: Assimilation of Multiple, Heterogeneous Data Sets to Enhance Predictability of Future Carbon Sink dynamics in the North America Terrestrial Ecosystems

9.C: Assimilation of Multiple, Heterogeneous Data Sets to Enhance Predictability of Future Carbon Sink dynamics in the North America Terrestrial Ecosystems Yiqi Luo, University of Oklahoma, yluo@ou.edu (Presenting) Nathan M Urban, Penn State University, nurban@psu.edu Kenneth J. Davis, Penn State University, davis@meteo.psu.edu Klaus Keller, Penn State University, kkeller@geosc.psu.edu Peter Thornton, Oak Ridge National Laboratory, thorntonpe@ornl.gov Mac Post, Oak Ridge National Laboratory, wmp@ornl.gov Ensheng Weng, University of Oklahoma, esweng@ou.edu Key factors that determine future continental-scale carbon sink dynamics are disturbance regimes and climate change. Natural and man-

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made disturbances create disequilibrium between carbon influx and efflux. Recovery after disturbances is regulated by ecosystem biogeochemical processes and tends to equilibrate carbon influx and efflux. The disturbances and recovery are two opposite forces to form dynamic disequilibrium (DD) of carbon cycling and to determine the carbon sink/source strength. Climate change can influence both disturbance regimes and recovery processes. In addition, climate change as pressing forces themselves can cause disequilibrium of carbon cycling and influence carbon sink/source strength. The major challenge to project future carbon sink dynamics in North America is to integrate various processes together and use multiple data sets to constrain those processes. This presentation will first review major research results on disturbance regimes, recovery processes, and climate change effects on carbon processes. Second, we will examine various existing conceptual and quantitative frameworks that enable integration of diverse processes and heterogeneous data towards predictive understanding of future regional carbon sink dynamics. Third, we will assess current status and research capability in the NACP community to quantitatively assimilate multiple, heterogeneous data to constrain diverse processes underlying continental carbon sink dynamics. One example is the Earth system Models of Intermediate Complexity (EMICs), which provide an effective means of combining a wide variety of observational constraints in a statistically sound fashion to improve our ability to predict the future North American carbon cycle. The method employs a fast statistical approximation to the model so that the assimilation is computationally tractable. Finally, we will discuss future research needs to improve the predictability of future carbon sink dynamics in the North American terrestrial ecosystems. Keywords: Prediction 9.D: A New Method for Evaluating the Ocean Acidification of Coastal Waters Using Chemical and Hydrographic Data

9.D: A New Method for Evaluating the Ocean Acidification of Coastal Waters Using Chemical and Hydrographic Data Richard Alan Feely, PMEL/NOAA, richard.a.feely@noaa.gov (Presenting) Burke Hales, OSU, bhales@coas.oregonstate.edu Chris Sabine, PMEL/NOAA, chris.sabine@noaa.gov Dana Greeley, PMEL/NOAA, dana.greeley@noaa.gov Kitack Lee, Pohung University, ktl@postech.ac.kr Simone Alin, PMEL/NOAA, simone.r.alin@noaa.gov Laurie Juranek, PMEL/NOAA, laurie.juranek@noaa.gov In a recent study (Feely et al., 2008), we determined that the continental shelf of western North America is strongly impacted in the spring and summer months by the upwelling of ‘ocean acidified’ water. Using the data from this same 2007 North American Carbon Program west coast cruise, we have developed regional algorithms for estimating aragonite saturation state from chemical and hydrographic data. Our approach utilizes a multi-parameter linear regression of aragonite saturation values as a function of temperature, salinity and oxygen so a broader range of cruise data sets can be used to evaluate spatial and temporal variability in saturation state. The calculated saturation states agree well with the measured values. For coastal waters off Oregon and California we obtained an overall R2 of 0.97 and a standard error 0.1 over a depth range from 30 – 200m. The method is reasonably straightforward and has good resolving power for aragonite saturation. Similar observations for coastal waters off Japan, Korea, and Russia yielded an overall R2 of 0.998 and a standard error (omega-aragonite) of 0.03 over a depth range of 30 - 1000 m. Keywords: Diagnosis, Attribution, Prediction, Coastal Synthesis

Decision Support Talks 10.A: Monitoring Requirements for Greenhouse Gas Markets and Registries

10.A: Monitoring Requirements for Greenhouse Gas Markets and Registries Richard Birdsey, USDA Forest Service, Northern Research Station, rbirdsey@fs.fed.us (Presenting) Linda Heath, USDA Forest Service, Northern Research Station, lheath@fs.fed.us Coeli Hoover, USDA Forest Service, Northern Research Station, choover@fs.fed.us Emerging mechanisms for managing greenhouse gases include carbon markets and registries such as the U.S. greenhouse gas registry administered by the Department of Energy, the Chicago Climate Exchange, and payment for actions such as Reducing Emissions from Deforestation and Degradation. Reporting entities must consider the typically strict requirements for monitoring and verification, leading to a need for developing and maintaining decision support systems. All greenhouse gas markets and registries have specific accuracy standards so that the additional emissions reduction or sequestration can be quantified and specifically attributed to the actions taken and to the appropriate reporting entity. Effective characterization of uncertainty is essential and will affect the value of the credits or debits. Monitoring and verification needs are related to scale – landowners may need to monitor carbon stocks on specific tracts of land; larger entities may need to keep track of emissions and sequestration from many kinds of integrated operations; and reporting or verification may be needed for political domains such as states or countries. With different options available for measuring, monitoring, and verifying greenhouse gas emissions and sinks, how does a reporter know when a decision-support tool provides accurate results and is ready for use? Some guidance is available in the literature about when information is suitable for use in policy and management decisions. The most useful decision-support tools include attention to capacity for delivering the science and technology is a usable format, and technical assistance to reporting entities. This is an ongoing process – needs will evolve as markets and registries coalesce into more consistent and integrated international mechanisms, and as carbon cycle science presents better understanding about the links between emissions, sequestration, and climate. Keywords: Decision Support 10.B: Land use decision making as a driver of carbon sequestration at multiple scales: A Colorado case study

10.B: Land use decision making as a driver of carbon sequestration at multiple scales: A Colorado case study Lisa Dilling, University of Colorado, Boulder, ldilling@colorado.edu (Presenting)

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Elisabeth Failey, University of Colorado, Boulder, betsy.failey@colorado.edu As society begins to address the issue of climate change, policy discussions have emerged on the role of land use as a means to sequester carbon. Land use is already a key player in the global carbon budget as humans have been altering vegetation and soils for agriculture and forestry purposes. At the heart of land use is human decision making. The land use pattern and its attendant carbon impacts are the end result of a complex set of policy, economic and cultural drivers that are channeled and expressed through individuals making decisions about land use. In order to understand the current pattern of carbon fluxes on managed land, and any future potential for land use to play a greater role in sequestering carbon, it is essential to understand the drivers of land use decision making at different scales, and their intersection with new imperatives and opportunities coming from climate mitigation goals. To this end, we have conducted a case study on land use decision making in the U.S. state of Colorado, a western state with significant portions of land managed by U.S. Federal governmental agencies in addition to privately-owned agricultural, grazing and forested lands. Our study has three significant components: 1) examining ownership patterns; 2) calculating the flux and carbon storage by land ownership category; and 3) illuminating the influences on land use decisions at different scales. Our main goal is to put together a first-order look at the types of decision makers involved in managing land, what influences their decisions, and how the potential for storage of additional carbon on land might vary according to ownership category and land vegetation type. Keywords: Decision Support 10.C: Carbon budget of Canada’s managed forest derived from a combined inventory and modeling approach

10.C: Carbon budget of Canada’s managed forest derived from a combined inventory and modeling approach Werner Alexander Kurz, Natural Resources Canada, Canadian Forest Service, wkurz@nrcan.gc.ca (Presenting) Graham Stinson, Natural Resources Canada, Canadian Forest Service, graham.stinson@nrcan.gc.ca Eric Neilson, Natural Resources Canada, Canadian Forest Service, eric.neilson@nrcan.gc.ca Caren Dymond, British Columbia Ministry of Forests and Range, caren.dymond@gov.bc.ca Celine Boisvenue, Natural Resources Canada, Canadian Forest Service, celine.boisevenue@nrcan.gc.ca Juha Mikael Metsaranta, Natural Resources Canada, Canadian Forest Service, juha.metsaranta@nrcan.gc.ca Brian Nelson Simpson, Natural Resources Canada, Canadian Forest Service, brian.simpson@nrcan.gc.ca Canada’s National Forest Carbon Monitoring Accounting and Reporting System (NFCMARS) was developed to meet international reporting requirements and to quantify the contribution of Canada’s managed forest to the global carbon (C) cycle. NFCMARS uses the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) to combine detailed forest inventory information with data on forest dynamics (growth and yield), natural disturbances (fires, insects, windthrow), forest management (harvesting, planting) and land-use change (afforestation, deforestation) to estimate annual emissions and removals of CO2 and non-CO2 greenhouse gases from 1990 onwards. Results indicate large differences between the 1990s and recent years in the importance of primary drivers of carbon stock changes. The large-scale outbreak of mountain pine beetle (Dendroctonus ponderosae) in western Canada is contributing to multi-year, regional carbon sources. Wildfires are contributing to very large interannual variation in the greenhouse gas balance of Canada’s managed forest, through both direct emissions in the year of the fires, and through post-fire decomposition of trees killed. NFCMARS estimates of average, regional NPP are consistent with those developed using other methods, but like all models that rely on empirical yield curves for the estimation of biomass dynamics, the NFCMARS estimates of NPP are not sensitive to interannual variations in environmental conditions, to changes in the concentration of atmospheric CO2, or to climate change. Uncertainty in the NFCMARS estimates of the C balance arise from errors in the input data, from uncertainty about the ecological parameters used to model soil C dynamics and disturbance effects, from processes that are excluded or incorrectly specified in CBM-CFS3 modelling framework, and from the computational algorithms used to initialize soil C stocks and select stands for disturbance. Keywords: Diagnosis, Regional/Continental Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics

Diagnosis Posters1: A Latitudinal, Longitudinal, and Monthly Description of the Fossil-Fuel-Carbon-Dioxide Emissions for the Countries of the North American Carbon Program

1: A Latitudinal, Longitudinal, and Monthly Description of the Fossil-Fuel-Carbon-Dioxide Emissions for the Countries of the North American Carbon Program Robert J Andres, Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6335 USA, andresrj@ornl.gov (Presenting) Tom A Boden, Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6335 USA, bodenta@ornl.gov Jay S Gregg, Department of Geography, University of Maryland, College Park, MD 20742 USA, gregg.jay@gmail.com London Losey, Department of Space Studies, University of North Dakota, Grand Forks, ND 58202-9008 USA, london.m.losey@gmail.com Gregg Marland, Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6335 USA, marlandgh@ornl.gov A detailed, mechanistic understanding of the global carbon cycle needs description in multiple dimensions (e.g., fine spatial scales, fine temporal scales, accurate and precise mass fluxes, isotopic descriptions, etc.). Carbon dioxide emissions from fossil fuels are central to increased interest in the carbon cycle and are critical toward understanding other fluxes in the carbon cycle. This presentation describes a subset of recent efforts that have produced a description of fossil-fuel-derived, carbon dioxide emissions at finer spatial and temporal scales than previously available. This subset focuses on the countries of the North American Carbon Program: Canada, the United States, and Mexico. Emission fluxes will be characterized in both mass and stable carbon isotope space. Past analyses of the monthly time series, in both mass and stable carbon isotope space, for individual countries have shown significant differences in the month-to-month emissions. For example, for the United States mass time series for the years 1984 to 2003, 46% of the months are statistically different at the 2-sigma level from the 1/12 approximation (a typical default distribution pattern obtained by dividing annual emissions equally among the 12 months).

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Gregg et al. (submitted) have described North American emissions at monthly and state/province scales for the period 1990 to 2007. Monte Carlo simulations have now been used to extrapolate the extant data to years for which no data exist at the desired spatial and temporal scales. This has resulted in a time series for the years 1950 to the present. The Monte Carlo simulations have been conducted individually for gas, liquid and solid fuels. Emissions from gas flaring and cement manufacture are currently not included. These results, when combined with global carbon cycle models, should lead to a better understanding of the global carbon cycle. The work presented here is part of a larger effort which extended this type of analysis to 18 more countries around the world. Collectively, these 21 countries describe, explicitly, a majority of the total fossil-fuel-derived carbon dioxide emission flux. These 21 countries, via extrapolation, will be used to estimate the global fossil-fuel-derived carbon dioxide emission flux. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 2: Gross Primary Productivity Response to Modes of Climate Variability

2: Gross Primary Productivity Response to Modes of Climate Variability Ian T Baker, Colorado State University, baker@atmos.colostate.edu (Presenting) A Scott Denning, Colorado State University, denning@atmos.colostate.edu Kevin Schaefer, National Snow and Ice Data Center, kevin.schaefer@nsidc.org Lara Prihodko, Natural Resources Ecology Laboratory, lara@nrel.colostate.edu The North American (NA) continent encompasses a variety of biological regimes: Tundra and Boreal Forest in the north, prairie, cropland and forest at lower latitudes, and desert in the southwest. These disparate biomes have unique responses to and influence on the atmosphere, both in the mean and during anomalous events. The integration of these responses over space and time determine continental-scale exchange of mass, energy and momentum between the atmosphere and terrestrial biosphere. It is appealing to link large-scale terrestrial response to modes of climate variability such as El Nino/Southern Oscillation (ENSO), Pacific-North America (PNA) or North Atlantic Oscillation (NAO) patterns. However, the size, meridional extent, and topographic complexity of NA make simple declarations of continental-scale carbon dynamics difficult. Furthermore, the overall carbon flux or Net Ecosystem Exchange (NEE) is the sum of respiratory and photosynthetic process that may have heterogeneously separate responses to changes in forcing. For the current study, we simplify the analysis by focusing on Gross Primary Productivity (GPP) so as to develop a mechanistic understanding of a fundamental process prior to making predictions of NEE. We evaluate the Simple Biosphere Model (SiB) at flux tower sites to demonstrate model ability. Demonstrable confidence in footprint-scale simulations will lend credence to simulations over larger domains. We then simulate surface fluxes over NA for a long temporal record and analyze mechanistic ecosystem response to climatic variability. Some fairly obvious general dependencies on temperature (Canada), precipitation (contiguous U.S.) and radiation (Pacific Northwest) emerge, although complex interactions between growing season and climatic variability remain. We find that no single mode of climate variability describes NA GPP, but various links between these modes and the mechanisms that influence GPP can be found.

Keywords: Diagnosis, Attribution, Site-level Synthesis, Regional/Continental Synthesis 3: Measurements of the ecosystem O2-CO2 stoichiometry at Harvard Forest

3: Measurements of the ecosystem O2-CO2 stoichiometry at Harvard Forest Mark O Battle, Bowdoin College, mbattle@bowdoin.edu (Presenting) Zane A Davis, Bowdoin College, zdavis@bowdoin.edu Ryan Hart, Now at Governor's Academy, rhart2@gmail.com Eric Sofen, Now at University of Washington, esofen@u.washington.edu Rebecca Perry, Now at Cabot Corporation, perry.becca@gmail.com Jayme Woogerd, Unafilliated, jwoogerd@gmail.com Jacob Scheckman, Now at University of Minnesota, jscheckm@me.umn.edu John Carpenter, Now at Amatek Corporation, john.carpenter@amatek.com We present more than two years of quasi-continuous measurements of the O2 and CO2 abundance in ambient air within and immediately above the canopy of a mid-latitude mixed deciduous forest. By considering the covariation in these abundances over time, we infer net stoichiometry of photosynthesis and respiration for all organisms active within the footprint of our sampling location. Preliminary analysis show that the ecosystem is processing about 1.03 moles of O2 for every mole of CO2 during the summer months. This result appears to be independent of the altitude of sampling (above vs. within the canopy), the time of day (night vs. day) and stratification of the boundary layer (high vs. low U*). In the winter, values are generally in the range of 1.26-1.35 and again show no clear altitude, time or wind-speed dependence. The summer results are consistent with recent work by Masiello et al. showing an elemental abundance ratio of 1.03+/-0.01 for leaf litter from a deciduous forest in Texas. Keywords: Diagnosis, Attribution, Software Tools, Instruments, Data Management, Programmatic Topics 4: Detrital carbon pools in temperate forests: magnitude and potential for landscape-scale assessment

4: Detrital carbon pools in temperate forests: magnitude and potential for landscape-scale assessment John B Bradford, USDA Forest Service, Northern Research Station, 1831 Hwy 169 E., Grand Rapids, MN 55744, jbbradford@fs.fed.us (Presenting) Peter Weishampel, University of Minnesota, Department of Soil, Water, and Climate, 1991 Upper Buford Circle, St. Paul, MN 55108, peter.weishampel@gmail.com Marie L. Smith, USDA Forest Service, Legislative Affairs, 201 14th Street, SW,, Washington, DC 20250-1130, marielouisesmith@fs.fed.us Randall Kolka, USDA Forest Service, Northern Research Station, 1831 Hwy 169 E., Grand Rapids, MN 55744, rkolka@fs.fed.us

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Richard A Birdsey, USDA Forest Service, Northern Research Station, 11 Campus Blvd., Suite 200, Newtown Square, PA 19073, rbirdsey@fs.fed.us Scott V Ollinger, Complex Systems Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, New Hampshire 03820, USA, scott.ollinger@unh.edu Michael G Ryan, USDA Forest Service, Rocky Mountain Research Station, 240 W. Prospect Ave., Fort Collins, CO 80523, mgryan@fs.fed.us Reliably estimating carbon storage and cycling in detrital biomass is an obstacle to carbon accounting. We examined carbon pools and fluxes in three, small, temperate forest landscapes to assess the magnitude of carbon stored in detrital biomass and determine if detrital carbon storage is related to stand structural properties (leaf area, aboveground biomass, primary production) that can be estimated by remote sensing. We characterized these relationships with and without forest age as an additional predictive variable. Results depended on forest type. Carbon in dead woody debris was substantial at all sites, accounting for ~17% of aboveground carbon, whereas carbon in forest floor was substantial in the subalpine Rocky Mountains (36% of aboveground carbon) and less important in northern hardwoods of New England and mixed forests of the upper midwest (~7%). Relationships with aboveground characteristics accounted for between 38% and 59% of the variability in carbon stored in forest floor and between 21% and 71% of the variability in carbon stored in dead woody material, indicating substantial differences between sites. Relating dead woody debris or forest floor to other aboveground characteristics and/or stand age may, in some forest types, provide a partial solution to the challenge of assessing fine-scale variability. Keywords: Diagnosis, Attribution 5: Chamber-Based Estimates of Methane Production in Coastal Estuarine Systems in Southern California

5: Chamber-Based Estimates of Methane Production in Coastal Estuarine Systems in Southern California Brian Brigham, San Diego State University, bbrigham@sunstroke.sdsu.edu (Presenting) David Lipson, San Diego State University, dlipson@sciences.sdsu.edu Chun-Ta Lai, San Diego State University, lai@sciences.sdsu.edu Wetland systems are believed to produce between 100 - 231 Tg CH4 yr-1 which is roughly 20% of global methane emissions. The uncertainty in methane emissions models stem the lack of detailed information about methane gas production within regional wetland systems. The aim of this study is to report the range of methane fluxes observed along salinity gradients at two San Diego coastal wetland systems, the Tijuana Estuary (Tijuana River National Estuarine Research Reserve) and the Peñasquitos Lagoon (Torrey Pines State Park Reserve). Soil water samples are used to elucidate factors responsible for the observed variation in methane fluxes. Air samples were subsequently collected from the headspace of a static soil chamber and stored in pre-evacuated vials. Methane concentrations were analyzed within hours after collection by gas chromatography in the laboratory. The chemical and physical properties of the soil, including salinity, pH, redox potential and temperature are measured with a hand-held probe nearby soil collars. The biological properties of the soil, including dissolved organic carbon, nitrate, and ammonia levels are measured from soil water samples in the laboratory. We find that saline sites under direct tidal influence produced methane fluxes ranging from -3.10 to 9.10 (mean 2.18) mg CH4 m-2 day-1. We also find that brackish sites (0.6 to 3.2 ppt in salinity) with fresh water input from residential runoff at the Peñasquitos Lagoon produced methane fluxes ranging from 0.53 to 192.10 (mean 33.34) mg CH4 m-2day-1. Sampling was done over the course of 5 weeks during August-September of 2008. We hypothesize that the contrasting methane fluxes found between the saline and the brackish sites is due primarily to the different salinity, and in turn sulfate levels found at the two sites. The reduction of sulfate to produce energy is more energetically favorable than the reduction of carbon dioxide to produce methane. Thus the presence of sulfate may act as a methanogensis inhibitor resulting in higher methane flux in low salinity conditions such as those found at the brackish sites. Keywords: Diagnosis, Attribution 6: Airborne Laser Remote Measurements of Atmospheric Carbon Dioxide

6: Airborne Laser Remote Measurements of Atmospheric Carbon Dioxide Edward V. Browell, NASA Langley Research Center, edward.v.browell@nasa.gov (Presenting) Michael E. Dobbs, ITT Corp., mike.dobbs@itt.com Jeremy Dobler, ITT Corp., jeremy.dobler@itt.com Susan A. Kooi, NASA Langley Research Center, susan.a.kooi@nasa.gov Yonghoon Choi, NASA Langley Research Center, yonghoon.choi-1@nasa.gov F. Wallace Harrison, NASA Langley Research Center, fenton.w.harrison@nasa.gov Berrien Moore III, Climate Central, bmoore@climatecentral.org T. Scott Zaccheo, AER, Inc., szaccheo@aer.com The recent development and demonstration of an airborne laser remote sensing capability for CO2 enables an entirely new way of investigating regional to continental-scale variations in sources and sinks of CO2. With this laser absorption spectrometer (LAS) system, column CO2 measurements between the aircraft and the ground can be made continuously along the ground track of the aircraft, and thus large areas can be efficiently covered to investigate CO2 variations over different ecosystems and source regions and to conduct CO2 budget studies over North America. This airborne CO2 LAS system uses a multi-frequency, single-beam LAS that operates in the 1.57-micron region, and it has been successfully flight tested in five airborne campaigns conducted over Oklahoma, Michigan, New Hampshire, and Virginia under a wide range of atmospheric conditions. Remote LAS measurements have been compared to high-quality in situ CO2 measurements obtained from the same aircraft on spirals under the ground track of the LAS. LAS flights have been conducted over a wide range of land and water reflectances and in the presence of scattered clouds. LAS CO2 column measurements with a precision of better than 2 ppm were obtained for a 100-m horizontal average over land and for a 1-km average over water. Absolute comparisons of CO2 remote and in situ measurements showed excellent agreement to better than 2 percent. The application of this airborne LAS system to large-scale studies of CO2 could revolutionize the study of CO2 variability over North America. Details of the measurement capabilities of this system and the potential application of it to CO2 source/sink investigations are discussed in this paper.

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Keywords: Diagnosis, Regional/Continental Synthesis 7: Spatiotemporal distributions of atmospheric CO2 from high resolution in-situ measurements over North America during NASA Field Campaigns (2004-2008)

7: Spatiotemporal distributions of atmospheric CO2 from high resolution in-situ measurements over North America during NASA Field Campaigns (2004-2008) Yonghoon Choi, National Institute of Aerospace, yonghoon.choi-1@nasa.gov (Presenting) Stephanie A. Vay, NASA Langley Research Center, stephanie.a.vay@nasa.gov Jung-Hun Woo, Konkuk University, woojh21@gmail.com Kichul Choi, Konkuk University, minic3000@gmail.com Krishna P. Vadrevu, Ohio State University, krisvkp@yahoo.com Edward V. Browell, NASA Langley Research Center, edward.v.browell@nasa.gov Susan A. Kooi, Science Systems and Applications, Inc., susan.a.kooi@nasa.gov The National Aeronautics and Space Administration (NASA) has recently conducted a number of airborne science missions over North America and adjacent oceans to understand the impact of long-range transport of trace gases and aerosols on the changing chemical composition of the troposphere. Regional-scale measurements were made over the eastern United States (INTEX-NA summer 2004); Mexico (MILAGRO March 2006); the eastern North Pacific and Alaska (INTEX-B May 2006); the Canadian Arctic (ARCTAS spring and summer 2008); and California (CARB June 2008). Smaller-scale field experiments associated with the calibration/validation activities of a new active remote CO2 sensor under development by ITT and NASA Langley have also been undertaken in OK, MI, NH, and VA. For these field campaigns, instrumentation for the in situ measurement of CO2 was integrated on various NASA research and commercial aircraft providing high-resolution (1 second) data traceable to the global calibration scale. These observations provide unique and definitive data sets via their intermediate-scale coverage and, frequent vertical profiles throughout the troposphere (0.1 – 12 km) for use in inversion and other global modeling studies. In this presentation, the spatiotemporal distribution of CO2 will be examined in conjunction with other source tracer species, back-trajectory analyses, and FLEXPART model outputs to characterize the observed spatial, seasonal, and inter-annual variability of CO2. Keywords: Diagnosis, Regional/Continental Synthesis 8: Mapping Forest Crown Cover, Mean Canopy Height, and Aboveground Biomass using a Geometric-Optical Model and MODIS Data

8: Mapping Forest Crown Cover, Mean Canopy Height, and Aboveground Biomass using a Geometric-Optical Model and MODIS Data Mark James Chopping, Montclair State University, choppingm@mail.montclair.edu (Presenting) Crystal Schaaf, Boston University, schaaf@bu.edu Feng Zhao, Boston University, zhao26@bu.edu Zhuosen Wang, Boston University, wangzhs@bu.edu Geometric-optical (GO) models have been shown to be useful in the interpretation of multiangle image data from NASA's MISR instrument in terms of forest canopy crown cover, mean canopy height, and aboveground woody biomass. The GO model inversion framework uses a simplified GO model with a priori prediction of the background contribution via regression on the kernel weights of a semi-empirical BRDF model. The model is adjusted against the data by allowing the mean crown radius and mean crown aspect ratio parameters to be free. Mean canopy height is then estimated using the retrieved values. This method has been used to map forest canopy structural parameters over large areas in the southwestern US, showing good agreement with US Forest Service estimates. We applied the same technique using a MODIS red band multiangle data set at 250 m nominal spatial resolution that was constructed via accumulation over a short period at the end of the dry season in 2002 (DOY: 153-164). Mean and standard deviation of the model fitting root mean square error were 0.02 and 0.006, respectively. After removal of outliers and unphysical values, the mean absolute error in estimates of cover, mean canopy height, and biomass vs estiimates extracted from a Forest Service map were 0.09, 8.4 meters, and 4.5 tons acre-1(10.1 Mg ha-1), with coefficients of determination of 0.55, 0. 50, and 0.75, respectively. These results are similar to those obtained using MISR but currently show slightly lower accuracy because a sub-optimal set of background prediction coefficients was used; we expect them to improve importantly with refinement of the coefficient set used for background prediction. The ability to map forest canopy parameters over large areas and at low cost using existing NASA Earth Observing System data opens new avenues for science investigations into patterns of disturbance and recovery, height-structured ecosystem modeling, forest management, and carbon loss from wildfire. Keywords: Diagnosis 9: Probabilistic upscaling of eddy flux measurements in the upper Great Lakes: Working towards the next generation MODIS GPP algorithm

9: Probabilistic upscaling of eddy flux measurements in the upper Great Lakes: Working towards the next generation MODIS GPP algorithm Kenneth J. Davis, Penn State, davis@meteo.psu.edu (Presenting) Jingfeng Xiao, Penn State, jing@psu.edu Ryan Anderson, University of Montana, ryan.anderson@ntsg.umt.edu Paul Bolstad, University of Minnesota, pbolstad@umn.edu Kelly Cherrey, Penn State, kcherrey@meteo.psu.edu Bruce Cook, University of Minnesota, brucecook@umn.edu Ankur Desai, University of Wisconsin, desai@aos.wisc.edu Randy Kolka, USDA Forest Service, rkolka@fs.fed.us Steve Running, University of Montana, swr@ntsg.umt.edu Nicanor Saliendra, USDA Forest Service, nsaliendra@fs.fed.us Ben Sulman, University of Wisconsin, bnsulman@wisc.edu Peter Weishampel, University of Minnesota, peter.weishampel@gmail.com Diagnosis of regional-scale ecosystem-atmosphere carbon fluxes remains a challenge. The MODIS GPP/NPP algorithm is arguably the most successful, quasi-operational, bottom-up terrestrial carbon flux diagnostic available to date. This method integrates global remote sensing of land cover and incoming radiation with meteorological data to create maps of photosynthesis that cover the entire terrestrial biosphere with

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8-day temporal resolution. Nevertheless, this approach has notable limitations. It does not diagnose heterotrophic respiration, it incorporates very limited information related to ecosystem disturbance, it is not calibrated in a statistically rigorous fashion, the limited spatial resolution of the land cover product handicaps our ability to apply the algorithm in highly heterogeneous regions, its estimates of leaf area index are often poor in heavily vegetated regions, and the approach does not provide information concerning the accuracy of the flux estimates. The Chequamegon Ecosystem-Atmosphere Study (ChEAS), spanning a highly heterogeneous and densely observed region of northern Wisconsin and Michigan, provides a test bed for development of a next generation algorithm. Flux tower observations from more than 15 sites in the region show dramatic differences in net ecosystem exchange (NEE) of CO2 over a small spatial scale with strong variations across vegetation cover and stand age. The small scale of heterogeneity in the region makes the differences in vegetation cover impossible to capture using the standard 1 km resolution of the MODIS land cover product. We are developing a next generation algorithm utilizing the unique observational density in this region. We are merging MODIS observations and meteorological data with high resolution land cover maps, continuous assimilation of flux tower observations, and measurements of the variability in above ground biomass within vegetation cover types to produce probabilistic maps of NEE of CO2 in the ChEAS study region. The product will be evaluated using independent flux tower measurements and forest inventory plots. The algorithm will be tested outside the study region to determine its robustness and portability, and the value of the new observations used in this flux diagnosis (flux towers, higher resolution land cover maps, above ground biomass data). Keywords: Diagnosis 10: Carbon pools and fluxes in a coastal plain loblolly pine plantation

10: Carbon pools and fluxes in a coastal plain loblolly pine plantation Michael Gavazzi, USDA Forest Service, SGCP, mgavazzi@fs.fed.us (Presenting) Asko Noormets, North Carolina State University, anoorme@ncsu.edu Steve McNulty, USDA Forest Service, SGCP, smcnulty@fs.fed.us Ge Sun, USDA Forest Service, SGCP, gesun@fs.fed.us JC Domec, North Carolina State University, jcdomec@ncsu.edu John King, North Carolina State University, jsking5@ncsu.edu Jiquan Chen, University of Toledo, jiquan.chen@utoledo.edu Emrys Treasure, USDA Forest Service, SGCP, etreasure@fs.fed.us Ecosystem carbon (C) pools and fluxes in coastal plain forests remain less studied compared to upland systems, even though the carbon stocks in these systems may be up to an order of magnitude higher. We report C pools and vegetation-atmosphere CO2 exchange during three hydrologically contrasting years (2005-2007) in a coastal plain loblolly pine plantation in North Carolina. The forest was a strong C sink during all years, sequestering 361±67, 835±55 and 724±55 g C m-2 yr-1 according to eddy covariance measurements between 2005 and 2007, respectively. The interannual differences in net ecosystem exchange of CO2 (NEE) were traced to a drought-induced decrease in canopy conductance that correlated better with precipitation deficit than with soil volumetric water content (VWC). The light response of NEE suggested that in addition to differences in gross ecosystem productivity (GEP), lower ecosystem respiration (ER) during the drier years may have contributed to the observed interannual differences in NEE, even though the differences in ER itself and its response to temperature and VWC were not statistically significant among the years. Although the contribution of heterotrophic respiration (Rh) to ER was relatively low (24-29%), and relatively consistent among years, it was 91-129% of the annual litter input. Litter input exceeded Rh during the two drier years, and was 29% less during the wettest year (lowest GEP and highest ER), suggesting that soil carbon stocks at the site are sensitive to precipitation regime. Overall, the response of C fluxes to contrasting moisture availability was more limited than reported for upland ecosystems, and the drought effect was mediated by demand (VPD) rather than supply (VWC), implying physiological limitations to water transport. Keywords: Diagnosis, Site-level Synthesis 11: The Vulcan Project: Methods, Results, and Evaluation

11: The Vulcan Project: Methods, Results, and Evaluation Kevin Robert Gurney, Purdue University, kgurney@purdue.edu (Presenting) Daniel Mendoza, Purdue Univeristy, daniel.l.mendoza@gmail.com Marc Fischer, Lawrence Berkeley National Laboratory, mlfischer@lbl.gov Kathy Corbin, Colorado State University, kdcorbin@atmos.colostate.edu Chris Miller, Purdue University, ccmiller@purdue.edu Bedrich Benes, Purdue University, bbenes@purdue.edu Nathan Andrysco, Purdue University, nandrysc@purdue.edu Simon Ilyushchenko, Google Inc., simonf@simonf.com Stephanie de la Rue du Can, Lawrence Berkeley National Laboratory, sadelarueducan@lbl.gov Scott Denning, Colorado State University, denning@atmos.colostate.edu Dennis Ojima, Colorado State University, ojima@heinzctr.org The Vulcan Project has quantified fossil fuel CO2 for the United States at the sub-county spatial scale, hourly for the year 2002 and is a key component of attributing CO2 fluxes within the North American Carbon Program. Vulcan approached quantification of fossil fuel CO2 from a novel perspective: leveraging the information already contained within the EPA’s National Emissions Inventory for the assessment of nationally regulated air pollution. By utilizing the inventory emissions of carbon monoxide and nitrogen oxides combined with emission factors specific to combustion device technology, we have calculated CO2 emissions for industrial point sources, powerplants, mobile sources, residential and commercial sectors with information on fuel used and source classification information. In the case of area-based sources (residential, commercial, mobile), we have downscaled county flux amounts using US Census data and GIS road networks. In this presentation, we provide an overview of the Vulcan inventory methods, results and evaluation of the Vulcan inventory by comparing to state-level inventories and other independent estimates. Vulcan is contributing to the mid-continent synthesis and our improved inventory for that domain will be highlighted. The inventory has been placed onto Google Earth and we will provide a preview of this capability along with preliminary results of an urban-scale GIS-based inventory that is currently under construction. Finally, we will present the result of fossil fuel CO2 concentration as transported by an atmospheric transport model and a comparison to in situ CO2 observations.

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Keywords: Diagnosis, Attribution, MCI Synthesis 12: The Carbon Balance of North American High-latitude Terrestrial Ecosystems in Response to Changes in Atmospheric Chemistry, Climate and Disturbance Regime

12: The Carbon Balance of North American High-latitude Terrestrial Ecosystems in Response to Changes in Atmospheric Chemistry, Climate and Disturbance Regime Daniel J Hayes, University of Alaska Fairbanks, ffdjh1@uaf.edu (Presenting) A David McGuire, University of Alaska Fairbanks, ffadm@uaf.edu David W Kicklighter, Ecosystems Center, Marine Biological Laboratory, dkick@mbl.edu Jerry M Melillo, Ecosystems Center, Marine Biological Laboratory, jmelillo@mbl.edu Analyses of the global carbon budget suggest that terrestrial ecosystems have been responsible for slowing the rate of anthropogenic CO2 build-up in the atmosphere through carbon uptake and storage, with northern extratropical regions responsible for most of this land-based CO2 sink. However, recent changes in atmospheric chemistry, climate trends, disturbance regimes, land use and management systems in northern high latitude regions have the potential to alter the terrestrial sink of atmospheric CO2. To determine the recent trends in the carbon balance of North American arctic and boreal ecosystems, we performed a retrospective analysis of terrestrial ecosystem dynamics across this region (north of 45oN latitude) using a process-based biogeochemistry model. The results of the simulations suggest a shift in direction of the net flux from the terrestrial sink of earlier decades to a net source on the order of 27.5 Tg C per year between 1997 and 2006. The positive carbon balance (sink) estimated for tundra regions is consistent with observations suggesting a “greening” of, or an increase in productivity in, these ecosystems. However, the simulation framework and subsequent analyses presented in this study attribute the overall shift in regional carbon balance primarily to a large loss of carbon as a result of “browning” in boreal forest ecosystems. Model results suggest that primary productivity of the boreal forest declined over this recent time period in response to a decreasing trend in water balance. However, the substantial release of CO2 as a direct result of the large area of boreal forest burned during the past decade was the largest signal in the overall negative carbon balance for this region. Our results, along with those of other recent studies, emphasize the importance of changes in the disturbance regime (e.g., fire events and insect outbreaks) in the weakening and possible disappearance of the terrestrial C sink in high latitude ecosystems. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 13: Forest dynamics in southeastern United States assessed using time series stacks of Landsat observations

13: Forest dynamics in southeastern United States assessed using time series stacks of Landsat observations Chengquan Huang, Department of Geography, University of Maryland, College Park, MD 20742, cqhuang@umd.edu (Presenting) Ainong Li, Department of Geography, University of Maryland, College Park, MD 20742, ainongli@umd.edu Hua Shi, ASRC Research and Technology Solutions, Contractor to USGS/EROS, Sioux Falls, SD 57198, hshi@usgs.gov James Vogelmann, ASRC Research and Technology Solutions, Contractor to USGS/EROS, Sioux Falls, SD 57198, vogel@usgs.gov Zhiliang Zhu, USDA Forest Service, 1601 N. Kent Street, Arlington, VA 22209, zzhu@fs.fed.us Chris Toney, Rocky Mountain Research Station, Fire Sciences Lab, 5775 US W Highway 10, Missoula, MT 59808, christoney@fs.fed.us Nancy Thomas, Department of Geography, University of Maryland, College Park, MD 20742, nthomas1@umd.edu Samuel N. Goward, Department of Geography, University of Maryland, College Park, MD 20742, sgoward@umd.edu Jeffrey G Masek, Biospheric Sciences Branch, NASA Goddard Space Flight Center, Greenbelt, MD 20771, jeffrey.g.masek@nasa.gov The southeastern U.S. is characterized with active forestry activities and vigorous forest regeneration. The objective of this study is to quantitatively assess forest change in this region using Landsat images acquired over the last two decades. The study area is defined as the two Bailey’s ecological provinces: the coastal plains forest province and southeastern mixed forest province, which encompass parts of the states of Mississippi, Alabama, Georgia, Florida, South Carolina, North Carolina, Tennessee, and Virginia. The entire study area consists of ~50 World Reference System (WRS) tiles. For each WRS tile, we assembled a time series stack of Landsat images (LTSS) from 1984 to current with a nominal temporal interval of two years. The LTSS were analyzed using a vegetation change tracker (VCT) algorithm to map forest changes, which will be used to analyze the rates of forest changes and their spatial and temporal variability across the entire study area. Results from this study will be highly valuable for carbon studies. The wall-to-wall coverage and the spatial and temporal details of the derived forest change products provide an unprecedented opportunity for modelers to reduce uncertainties in quantifying carbon flux arising from forest dynamics for the study area. The spatial details in these change products will satisfy many ecological applications including biodiversity conservation and habitat fragmentation studies, while the biennial temporal resolution and wall-to-wall coverage will facilitate studies at a spectrum of spatial and temporal scales. In addition, the change detection capability developed through this study can be used in routine ecosystem monitoring using current satellite observations and historical satellite data archives. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis, Coastal Synthesis 14: The Resolution of the North American CO2 Observing Network as Seen by CarbonTracker

14: The Resolution of the North American CO2 Observing Network as Seen by CarbonTracker Andrew R Jacobson, NOAA Earth System Research Lab, andy.jacobson@noaa.gov (Presenting) Arlyn E Andrews, NOAA Earth System Research Lab, arlyn.andrews@noaa.gov Kenneth A Masarie, NOAA Earth System Research Lab, kenneth.masarie@noaa.gov Colm Sweeney, NOAA Earth System Research Lab, colm.sweeney@noaa.gov Wouter Peters, NOAA Earth System Research Lab, wouter.peters@noaa.gov John B Miller, NOAA Earth System Research Lab, john.b.miller@noaa.gov Thomas J Conway, NOAA Earth System Research Lab, thomas.j.conway@noaa.gov James H Butler, NOAA Earth System Research Lab, james.h.butler@noaa.gov Pieter Tans, NOAA Earth System Research Lab, pieter.tans@noaa.gov The CarbonTracker inversion system captures a clear signal of the 2002 North American drought, estimating a flux anomaly of 0.5 PgC/yr in the face of a climatological uptake of about 0.7 PgC/yr in North America.

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In contrast, CarbonTracker has found no significant CO2 flux signal from the summer 2007 drought in the US southeast. In part this is due to differential observability; whereas the interior of the continent is relatively well-covered by calibrated CO2 observations, the southeast is generally underobserved. We present here results of observational system simulation experiments (OSSEs) using the CarbonTracker system, meant to assess the ability of current and anticipated CO2 measurement networks to detect flux anomalies in North America. In separate experiments, artificial flux anomalies are imposed in the upper midwest and in the US southeast during the summer. Resultant CO2 anomalies are propagated through the atmosphere using the CarbonTracker system, and sampled at the places and times where real observations are available. These synthetic data are then fed back to CarbonTracker to see how much of the imposed flux anomaly can be retrieved. Initial results suggest that the estimated flux response is complex and involves the entire globe, and that there is significant disparity in the network resolution for the two regions: about 90% of an upper-midwest flux anomaly can be detected, compared to only about 10% for a southeastern flux anomaly. We evaluate the power of both the current observational network and a planned larger network comprising 12 tall towers and 24 weekly aircraft profiles in North America. Keywords: Diagnosis 15: Residential Carbon: Characterizing the carbon cycle in urban grasslands

15: Residential Carbon: Characterizing the carbon cycle in urban grasslands Jennifer C Jenkins, University of Vermont, jennifer.c.jenkins@uvm.edu (Presenting) Peter M Groffman, Cary Institute of Ecosystem Studies, groffmanp@ecostudies.org John Butnor, USDA Forest Service, jbutnor@fs.fed.us Paul J. Lilly, University of Vermont, pjlilly@uvm.edu Amanda K. Holland, University of Vermont, akhollan@uvm.edu Mary Cadenasso, University of California, Davis, mlcadenasso@ucdavis.edu Residential lands cover a substantial portion of the land area in the United States, and this portion is increasing with time. Despite the importance of these areas, little is currently known about biogeochemical cycles in residential environments. In this study, we present results from a series of studies developed to understand the factors that drive carbon cycling in urban grasslands. Field sites are located along a climatic gradient from the Baltimore Ecosystem Study (Baltimore, MD) to Burlington, VT. In these urban grasslands, aboveground standing stock does not vary substantially with biophysical or sociodemographic factors. However, fluxes including productivity, soil respiration, and total belowground carbon allocation (TBCA) are driven strongly by biophysical factors such as soil texture as well as sociodemographic factors such as irrigation, mowing height, and fertilization. Results from this work will be used to develop a large-scale understanding of spatial and temporal patterns in C and N cycling in these heterogeneous residential systems.

Keywords: Diagnosis 16: Northeastern US forest response to changing climate and atmospheric chemistry

16: Northeastern US forest response to changing climate and atmospheric chemistry Julian P Jenkins, University of New Hampshire, julian.jenkins@unh.edu (Presenting) Scott V Ollinger, University of New Hampshire, scott.ollinger@unh.edu Christine Goodale, Cornell University, clg33@cornell.edu Christina Tonitto, Cornell University, ct244@cornell.edu We present model predictions of potential carbon storage and dynamic carbon fluxes for the temperate and transitional-boreal forests of the mid-Atlantic and northeastern United States. We use the PnET-CN terrestrial ecosystem model, which is driven principally by the relationship between predicted foliar nitrogen concentrations and maximum photosynthetic rates, in conjunction with 100 year climate predictions from a suite of GCM outputs and IPCC derived CO2 emission scenarios. With this model, we observe a decrease in productivity in coniferous dominated regions due to moisture limitations and exceeded optimal photosynthetic conditions under long-term climate change scenarios. In contrast, above-ground productivity increases dramatically (50-80%) for deciduous species in the most extreme of the 100 year northeastern climate change scenarios before the CO2 fertilization effect eventually saturates. Model results indicate that CO2 enhancement of photosynthesis alone may have as large an effect on increased NPP as climate change for the first half of a 100 year climate change scenario. However, as fertilization saturates, temperature stress will exert a more prominent role in carbon sequestration dynamics. Many of the findings in this study highlight the poorly understood above and below-ground carbon allocation dynamics in ecosystem biogeochemical models. Studies from FACE experiments have observed an increasing diversion of carbon to fine root biomass growth under elevated atmospheric CO2 concentration. This is consistent with the physiological notion that N, water and other nutrients may become increasingly limited as photosynthetic rates rapidly increase under climatic change, thus promoting the growth of belowground root systems to increase absorption of and better scavenge for the limiting nutrient (frequently labile N in these systems). We discuss this modeling problem and suggest solutions within the framework of our regional analysis. Keywords: Diagnosis, Site-level Synthesis, Regional/Continental Synthesis 17: Net radiation and evapotranspiration estimated with satellite observations

17: Net radiation and evapotranspiration estimated with satellite observations

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Yufnag Jin, UCI, yufang@uci.edu (Presenting) Jim Randerson, UCI, jranders@uci.edu Mike Goulden, UCI, mgoulden@uci.edu Soil moisture links surface energy, water and biogeochemical cycles by several different pathways, including by influencing the partitioning of energy into latent and sensible heat and by regulating net primary production and heterotrophic respiration fluxes. Evapotranspiration (ET) is a major pathway for water loss from many ecosystems and its seasonal variation affects the seasonality of soil moisture and subsequently net ecosystem exchange. Here we estimated net radiation (Rnet) using MODerate resolution Imaging Spectroradiometer (MODIS) albedo and land surface temperature observations. We then used these estimates of Rnet to estimate ET using a Priestley-Taylor approach with an adjustable coefficient that was parameterized as a function of leaf area index and soil moisture using existing observational records from 30 Ameriflux sites. Good agreement was found between satellite-based estimates of Rnet and field-measured Rnet, with an absolute difference of annual mean net radiation of less than 30 W m-2. Monthly ET estimates agreed reasonably well with measurements from May 2006 to April 2007 in southern California tower sites. The spatial distribution of annual mean Rnet over California showed an increasing trend from deserts (107.9 ± 29.7 W m-2) to grasslands (117.0 ± 26.0W m-2), and from grassland to forests (150.6 ± 29.5 W m-2), reflecting decreasing albedo and surface temperature with increasing vegetation cover. The Rnet for agriculture areas (135.0 ± 17.1W m-2) is higher than that of grasslands. The relative difference of ET is much more significant than that of Rnet, with a mean annual ET ranging from 157.9 mm yr-1 in deserts, 392.1 mm yr-1 in grasslands, to 734.6 mm yr-1 in forests. The agriculture areas are exception with an ET of 1280.7 mm yr-1. The improved representation of soil moisture seasonality resulted in a better agreement between CASA model predictions of seasonal cycle of net ecosystem CO2 exchange and those derived from eddy covariance measurements from California. Keywords: Diagnosis, Regional/Continental Synthesis 18: Biogeochemical, Remote Sensing, and Modeling Approaches to Evaluating the Sources and Fates of Dissolved Organic Matter and Particles in the U.S. Middle Atlantic Bight

18: Biogeochemical, Remote Sensing, and Modeling Approaches to Evaluating the Sources and Fates of Dissolved Organic Matter and Particles in the U.S. Middle Atlantic Bight Antonio Mannino, NASA GSFC, antonio.mannino@nasa.gov (Presenting) Stan B. Hooker, NASA GSFC, stanford.b.hooker@nasa.gov Estuaries and the coastal ocean experience a high degree of variability in the composition and concentration of particulate and dissolved organic matter (DOM) as a consequence of riverine and estuarine fluxes of terrigenous DOM, sediments, detritus and nutrients into coastal waters and associated phytoplankton blooms. Our approach integrates biogeochemical measurements, optical properties, remote sensing, and a coupled physical-biogeochemical model to examine the sources and fates of organic matter in the U.S. Middle Atlantic Bight (MAB) and Gulf of Maine (GoM). Algorithms developed to retrieve colred DOM (CDOM), Dissolved (DOC) and Particulate Organic Carbon (POC) from NASA’s MODIS-Aqua and SeaWiFS satellite sensors are applied to study the processes that produce and remove organic matter in the coastal ocean. The relationships between DOC and CDOM vary seasonally and between regions requiring variable coefficients for each region (southern MAB, Hudson plume and western Gulf of Maine). Satellite validation analysis demonstrates successful retrieval of POC, DOC and the CDOM absorption coefficient (aCDOM) for the MAB. Our results show that CDOM is a major contributor to the bio-optical properties of the northeastern U.S. coast, accounting for 35-70% of total light absorption at 443 nm, as compared to 30-45% for phytoplankton and 0-30% for non- pigmented particles. Remote sensing of CDOM is applied to track terrigenous DOM and quantify DOC within the coastal ocean. The seasonal processes that influence CDOM distributions in the MAB include freshwater discharge, photooxidation, and wind-induced vertical mixing of the water column in autumn-winter. SeaWiFS and MODIS imagery reveal the importance of estuarine outflow from Chesapeake Bay and Delaware Bay to the export of CDOM and DOC to the coastal ocean and a net community production of DOC on the shelf of 12-34 µmol C/L between spring and summer. DOC and POC distributions are driven primarily by river/estuary discharge, net community production, and the ocean circulation pattern along the shelf and continental slope. As our work progresses, we will apply SeaWiFS and MODIS data and US ECoS model (Hofmann et al. 2008) results to quantify the inventories and fluxes of POC, DOC and aCDOM which can used to ascertain impacts of natural meteorological events and climate change on coastal marine ecosystems. Keywords: Site-level Synthesis, Regional/Continental Synthesis 19: Estimating the Amount, Spatial Distribution, and Statistical Uncertainty of Aboveground Carbon Stocks of the North American Boreal Forest Using the ICESAT-GLAS Spaceborne Lidar

19: Estimating the Amount, Spatial Distribution, and Statistical Uncertainty of Aboveground Carbon Stocks of the North American Boreal Forest Using the ICESAT-GLAS Spaceborne Lidar Ross F Nelson, NASA Goddard, ross.f.nelson@nasa.gov Hank A Margolis, Laval University, hank.margolis@sbf.ulaval.ca (Presenting) Hans E Andersen, USDA Forest Service, handersen@fs.fed.us Mike Wulder, Canadian Forest Service, mwulder@pfc.cfs.nrcan.gc.ca The boreal forest of North America covers around 263 million ha and is by far the largest forest biome on the continent. The changes in disturbance regimes that are likely to occur point to a pressing need to develop methods to evaluate C stocks at the biome level. Lidar remote sensing from spaceborne platforms offers an interesting opportunity for conducting such evaluations since it can provide the capability for repeated measurements over large spatial extents. The launch of the GLAS sensor on the ICESat satellite in 2003 offered the opportunity to evaluate the potential of a spaceborne lidar for measuring the aboveground structural properties of the boreal forest and a successful NASA-funded pilot project was recently completed in Quebec. Our current work builds on our recent advances to evaluate the aboveground biomass and C stocks at the continental scale for the boreal forest of North America. This poster describes our strategy, our most recent

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accomplishments, and our plans for the next two years. The approach employs a portable airborne LiDAR profiler that was designed specifically as a large area sampling tool to estimate forest volume, biomass, and C stocks. The airborne lidar flies over both ground inventory plots and along GLAS orbital transects. The sampling approach provides robust unbiased estimates and variances of aboveground C stocks. The study serves three purposes: 1) it provides a structural, spatially-explicit baseline of aboveground C stocks; a baseline which will change as the boreal climate warms; 2) it provides a statistical basis for generating unbiased C stock estimates and the variation associated with those estimates; and 3) it takes a significant step in developing procedures to measure and re-measure C stocks in regions where little information exists, regions which comprise a very significant portion of the Earth's terrestrial C stocks. Keywords: Decision Support, Regional/Continental Synthesis 20: Remotely sensed respiration vs. primary production in a coastal ocean ecosystem

20: Remotely sensed respiration vs. primary production in a coastal ocean ecosystem Patricia Matrai, Bigelow Laboratory for Ocean Sciences, pmatrai@bigelow.org (Presenting) Nicole Poulton, Bigelow Laboratory for Ocean Sciences, npoulton@bigelow.org Carlton Rauschenberg, Bigelow Laboratory for Ocean Sciences, carlton@bigelow.org Michael Sieracki, Bigelow Laboratory for Ocean Sciences, msieracki@bigelow.org We consider here the balance between primary production and respiration of fixed organic matter in the coastal ocean. We have re-evaluated published empirical relationships between bacterial abundance, respiration and production as well as with temperature, chlorophyll and primary production with a significantly enhanced compilation of field data, with the goal of remotely estimating ocean respiration. We have tested such algorithms in the coastal waters of the Gulf of Maine, using the remotely sensed parameters of temperature, chlorophyll, ocean color, and primary production. We have measured system productivity and respiration in the vicinity of the Kennebec River plume in the Gulf of Maine, a coastal shelf sea, over two seasonal cycles to establish the variability and magnitude of the organic matter metabolism of this system. We discuss the usefulness of this approach over larger temporal and spatial scales than is possible from field studies. Keywords: Diagnosis, Attribution 21: Integrating surface and space-based observations of atmospheric CO2 for inverse modeling of CO2 sources and sinks

21: Integrating surface and space-based observations of atmospheric CO2 for inverse modeling of CO2 sources and sinks Ray Nassar, University of Toronto, ray.nassar@utoronto.ca (Presenting) Dylan B.A. Jones, University of Toronto, dbj@atmosp.physics.utoronto.ca Jing M. Chen, University of Toronto, chenj@geog.utoronto.ca We conduct a series of Observing System Simulation Experiments (OSSEs) to assess the reduction in uncertainty of estimates of CO2 surface fluxes with different satellite measurements of atmospheric CO2. Using a Bayesian inversion approach, based on the GEOS-Chem global chemical transport model, we examine the impact of the different observing strategies and measurement precision of satellite instruments such as TES, AIRS, SCIAMACHY, IASI, OCO, and GOSAT on estimates of CO2 surface fluxes. The satellite measurements offer greatly increased spatial coverage but have lower precision than in situ measurements. We therefore explore the complementarity of combining the space-based observations with the highly accurate in situ surface CO2 measurements in a joint inversion estimate of CO2 sources and sinks. Keywords: Diagnosis 22: Estimation of the interannual variation of CO2 exchange between North American terrestrial ecosystems and the atmosphere using the simulation model GTEC

22: Estimation of the interannual variation of CO2 exchange between North American terrestrial ecosystems and the atmosphere using the simulation model GTEC Wilfred M. Post, ORNL, wmp@ornl.gov (Presenting) Anthony W. King, ORNL, kingaw@ornl.gov Lianhong Gu, ORNL, lianhong-gu@ornl.gov Jesse N. Miller, ORNL, millerjn@ornl.gov Shuyong Li, ORNL, lish@ornl.gov The variation of CO2 exchange at seasonal and interannual time scales is observed at fine spatial scales by eddy flux measurements at AmeriFlux sites and estimated at large spatial scales by inversion analyses of atmospheric CO2 concentrations and MODIS satellite observations, making it difficult to identify the locations and processes involved in North America terrestrial carbon sources and sinks. We use the physiologically based ecosystem biogeochemistry model Global Terrestrial Ecosystem Carbon (GTEC) to estimate the magnitude of the seasonal and interannual variation introduced by weather and leaf area index on CO2 exchanges for North America over the period of 2000-2005. We use North American Regional Reanalysis (NARR) with 32 km resolution as the input meteorology. The relatively fine spatial resolution of the results (32 km grid) allows identification of particular subregions and ecosystem types that contribute the greatest to the weather induced variations in CO2 exchange. We compare the spatial distribution of the interannual variations over this period with interannual variation in several MODIS products. Keywords: Diagnosis 23: Potential of Tracking Respiration Flux of North American Temperate Deciduous Forests Using MODIS Reflective and Thermal Image Data

23: Potential of Tracking Respiration Flux of North American Temperate Deciduous Forests Using MODIS Reflective and Thermal Image Data A. Faiz Rahman, Indiana University, farahman@indiana.edu (Presenting) Vicente D. Cordova, Indiana University, vdcordova@indiana.edu We report the potential of estimating ecosystem respiration (Re) of North American temperate deciduous forests by exclusive use of remotely sensed data from the moderate resolution imaging spectroradiometer (MODIS). Surface temperature (Tr) and enhanced vegetation index

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(EVI) data from MODIS, and respiration data from four AmeriFlux tower sites were used in this study. A total of 16 site-year data were involved. We used a multiple regression model with bilinear moderator effect to estimate Re from Tr and EVI. The modeled output was linearly correlated with Re across a wide range of values (0.4 to 8 g C m-2 d-1). Measured and modeled values were highly correlated for all sites (adjusted R2 = 0.82 to 0.96). This study demonstrates the potential of estimating ecosystem respiration by exclusive use of remotely sensed data from the existing space-based sensors. Keywords: Diagnosis, Site-level Synthesis 24: International Cooperation to Provide Consistent Landsat-based Estimates of Forest Carbon Change in North America

24: International Cooperation to Provide Consistent Landsat-based Estimates of Forest Carbon Change in North America Todd A. Schroeder, US Forest Service (Forest Inventory and Analysis Program), Todd.Schroeder@ubc.ca (Presenting) Sean P. Healey, US Forest Service (Forest Inventory and Analysis Program), seanhealey@fs.fed.us Gretchen G. Moisen, US Forest Service (Forest Inventory and Analysis Program), gmoisen@fs.fed.us Michael A. Wulder, Canadian Forest Service, mike.wulder@nrcan.gc.ca Rigoberto Rivas Palafox, CONAFOR (Mexico), rpalafox@conafor.gob.mx Samuel N. Goward, University of Maryland, sgoward@umd.edu Warren B. Cohen, US Forest Service (PNW Research Station), warren.cohen@oregonstate.edu Jeff B. Masek, NASA, jeffrey.g.masek@nasa.gov Robert E. Kennedy, Oregon State University, robert.kennedy@oregonstate.edu Chengquan Huang, University of Maryland, cqhuang@geog.umd.edu Scott L. Powell, US Forest Service (PNW Research Station), scott.powell@oregonstate.edu Nancy Thomas, University of Maryland, nthomas2@umd.edu Karen Schleeweis, University of Maryland, ska1@umd.edu The international borders within North America represent points of discontinuity in the depth of our understanding of the terrestrial carbon cycle. Canada, Mexico, and the United States all have each recently made important enhancements to their systematic forest inventories, but differences in the form and reporting of these inventories has hampered their use in consistent, continental carbon monitoring. The NASA-funded North American Forest Dynamics (NAFD) project is working closely with national inventories from each country, and is laying the groundwork for compatible estimates of the effects of disturbance on biomass loss and re-growth. Disturbance processes vary across the continent nearly as much as forest types do. NAFD is using time series of Landsat imagery, calibrated with systematic inventory data, to map and estimate the effects of those disturbances consistently across both time and space. The upcoming free release of the Landsat data archive will dramatically reduce costs associated with satellite-based study of forest carbon dynamics. To meet growing interest in the field, NAFD is working closely with the national forest inventories in Canada, Mexico and the United States to streamline the large-scale integration of satellite and inventory data. While the form of inventory data varies somewhat from country to country, the temporal and spatial consistency of Landsat data should allow us to transcend national borders and use more ecologically meaningful units (the terrestrial eco-regions on the right, for example) in characterizing continental carbon cycles. This poster summarizes activities in each country. Keywords: Diagnosis, Regional/Continental Synthesis 25: From Forest Structure To Forest Ecology: Relationships Between Forest Profiles from Interferometric SAR, Leaf Area Density, Biomass, and Ecosystem History

25: From Forest Structure To Forest Ecology: Relationships Between Forest Profiles from Interferometric SAR, Leaf Area Density, Biomass, and Ecosystem History Robert Treuhaft, Jet Propulsion Laboratory, California Institute of Technology, robert.treuhaft@jpl.nasa.gov (Presenting) Fabio Goncalves, Oregon State University, Fabio.Goncalves@oregonstate.edu This poster explores relationships between vertical forest structure information derived from interferometric SAR (InSAR) to various ecological metrics. Multibaseline InSAR data collected over the La Selva Biological Station in Costa Rica produced vegetation density profiles [Treuhaft et al., in review]. The assumptions required to interpret the InSAR profiles as leaf area density are shown. Many different relationships have been drawn between forest structure and biomass estimation [e.g. Drake et al. 2002, Treuhaft et al. 2003]. We explore several candidate relationships between InSAR profiles and biomass, as well as between moments of profiles and biomass. The correlation between stand age and various structural attributes is shown. Incidence of selective logging is also related to the structural parameter called “foliage height diversity” [Macarthur and Macarthur 1961], which can be estimated as a function of the InSAR profile. J. B. Drake, R. O. Dubayah, D. B. Clark, R. G. Knox, J. B. Blair, M. A. Hofton, R. L. Chazdone, J. F. Weishampel, and S. D. Prince, Estimation of tropical forest structural characteristics using large-footprint lidar , Remote Sensing of Environment, 79, 305, 2002. R. H. MacArthur and J. W. MacArthur, “ On bird species diversity,” Ecology, 42(3), 594, 1961. R. N. Treuhaft, B. D. Chapman, J. R. dos Santos, F. G. Gonçalves, L. V. Dutra, P. M. A. Graça, and J. B. Drake, “Vegetation profiles in tropical forests from multibaseline interferometric SAR, field, and lidar measurements,” Journal of Geophysical Research, Atmopsheres, in review. R. N. Treuhaft, G. P. Asner, and B. E. Law, Structure-based forest biomass from fusion of radar and hyperspectral observations,' Geophysical Research Letters, 30, 25-1, 2003.

Keywords: Diagnosis, Attribution, Decision Support, Regional/Continental Synthesis 26: Analysis of ARCTAS airborne CO2 measurements using geotechniques

26: Analysis of ARCTAS airborne CO2 measurements using geotechniques Krishna Prasad Vadrevu, The Ohio State University, OH 4691;, vadrevu.2@osu.edu (Presenting)

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Yonghoon Choi, 2National Institute of Aerospace, 100 Exploration Way, Hampton, VA 23666-6147, yonghoon.choi-1@nasa.gov Stephanie A Vay, NASA Langley Research Center, Chemistry and Dynamics Branch, Hampton, VA 23681, stephanie.a.vay@nasa.gov In this study, we evaluate the potential of geotechniques, i.e., remote sensing and geographic information systems in characterizing airborne CO2 measurements from the 2008 ARCTAS campaign. The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) was a major NASA field campaign designed to understand the transport and transformation of trace gases and aerosols on transcontinental and intercontinental scales and their impact on the composition of the arctic atmosphere and climate. During the spring and summer ARCTAS deployments, in situ CO2 measurements were made from the NASA DC-8 aircraft. This analysis focuses on CO2 data collected over California, Alaska and Canada and the use of MERIS and MODIS remote sensing data products to characterize the spatial patterns of vegetative land cover and fire for evaluating the observed CO2 variability. Also, a comparative analysis of CO2 data over land and near coastal regions in California versus land and ice regions in Alaska and Canada are performed. Spatial correlations are analyzed between the MODIS derived fires with the CO2 measurements. Geostatistics are used to characterize CO2 variations from land to near-coastal region. Preliminary results utilizing the 300m MERIS data indicate that the lowest CO2 mixing ratios were recorded over a landscape dominated by croplands in southern California (the San Joaquin Valley). CO2 emissions from the northern California wildfires that consumed Douglas and White Fir conifers and mixed Chaparral exceeded 400 ppmv. The highest CO2 concentrations were observed over the south central coastal region of California compared with those measured over the ice and snow-capped regions of Alaska and Canada that averaged 388 ppmv. In addition to reporting CO2 variations over different land cover types, the statistical analysis of CO2 with other biophysical datasets will be investigated and presented. Keywords: Diagnosis, Regional/Continental Synthesis 27: Mapping Canadian Wetlands Using L-band Radar Satellite Imagery

27: Mapping Canadian Wetlands Using L-band Radar Satellite Imagery Jane Whitcomb, The University of Michigan, jbwhit@umich.edu (Presenting) Mahta Moghaddam, The University of Michigan, mmoghadd@umich.edu (Presenting) Kyle mcDonald, JPL, kyle.mcdonald@jpl.nasa.gov Erika Podest, JPL, erika.podest@jpl.nasa.gov It is believed that the direct impacts of global warming will be most felt in the Earth’s high latitudes in various forms. The regions thought to be sensitive to climate change include patchy Arctic wetlands on continuous permafrost and those along the southern limit of permafrost in the Subarctic. The effects in these areas could take on a number of complex forms, and could cause wetlands to switch between carbon sources and sinks in so-far unquantified ways. Establishment of high-resolution baselines of northern wetland extent and distribution is therefore an essential goal for estimating sources, sinks, and net fluxes of CO2 and CH4 as well as providing a baseline against which to compare future changes. As part of a previous Carbon Cycle Science project, we have developed a robust algorithm for mapping boreal wetlands using L-band satellite radar imagery, and in particular have used the method to produce a complete vegetated wetlands map of Alaska using the JERS radar data. In this work, we apply this algorithm to produce a static map of Canadian wetlands from the 1997-98 era JERS radar data at 100-m resolution, to be followed by the 2007-era ALOS/PALSAR maps. In the Canadian classification system, wetlands generally refer to waterlogged land-cover types, include peatlands (bogs and fens), flooded vegetation (marshes and swamps), and shallow open waters. We use this system to generate the wetlands map of Canada. Both the summer and winter SAR imagery are being used. In addition, the required data layers are the texture and open water maps, both derived from the JERS backscatter data. For each pixel, the proximity to open water is also generated and included. The ancillary data layers required are the DEM, slope mask, and the SAR data acquisition date. The ground reference data used in developing the classification rules are obtained from various sources, including those from collaborators as well as from published literature. This presentation will show the latest results of the project, and will include the map of Canadian wetlands to the extent completed at the time of the NACP meeting. This work was performed at the University of Michigan and at the Jet Propulsion Laboratory, California Institute of Technology, through a grant and a contract, respectively, from the National Aeronautics and Space Administration. Keywords: Diagnosis, Prediction, Decision Support, Site-level Synthesis, Regional/Continental Synthesis 28: Decadal Change in Wetlands of Alaska Based on Analysis of ALOS/PALSAR and JERS SAR Data

28: Decadal Change in Wetlands of Alaska Based on Analysis of ALOS/PALSAR and JERS SAR Data Jane Whitcomb, The University of Michigan, jbwhit@umich.edu (Presenting) Mahta Moghaddam, The University of Michigan, mmoghadd@umich.edu (Presenting) Kyle mcDonald, JPL, kyle.mcdonald@jpl.nasa.gov Erika Podest, JPL, erika.podest@jpl.nasa.gov Bruce Chapman, JPL, bruce.chapman@jpl.nasa.gov Northern wetlands are believed to have hitherto served as carbon sinks, sequestering about one third of the total global pool of soil carbon. The warmer, drier conditions expected throughout the Arctic may induce aerobic decomposition of northern wetland soils, which may cause them to become major sources rather than sinks of carbon dioxide. It is therefore critical to develop an ability to monitor long-term changes occurring in the condition of northern wetlands. Since L-Band synthetic aperture radar (SAR) is sensitive to vegetation structure, biomass, and moisture content, it is an appropriate choice for detecting changes in the characteristics of vegetated wetlands. We have previously generated a state-wide map of vegetated wetlands in Alaska using two seasons of the L-band SAR imagery from the Japanese Earth Resources Satellite (JERS), from the 1997-1998 era. We are now generating the wetlands map of Alaska from the ALOS/PALSAR imagery, acquired in 2007. These data, separated in time by approximately one decade, are used to produce a thematic map of change in the type and extent of Alaskan wetlands. Here, we will present the results for several representative regions in Alaska, including sites in the tundra, scrub/shrub, and forested wetlands. To produce each set of classified wetlands maps, the SAR imagery is supplemented with the corresponding imagery collection dates, a digital elevation model (DEM), a slope model, an open water mask, proximity to water map, and geographic latitude. The classification algorithm for each data set is based upon using a multitude of decision trees. The accuracy of the resulting thematic change map will be verified using ground reference data. The results could demonstrate the capability of multi-platform satellite SAR observations for characterizing the transitions across multiple years in extent and type of vegetated wetlands as a result of

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global climate change, which will subsequently be used in carbon modeling in northern wetlands. This work was performed at the University of Michigan and at the Jet Propulsion Laboratory, California Institute of Technology, through a grant and a contract, respectively, from the National Aeronautics and Space Administration. Keywords: Diagnosis, Prediction, Decision Support, Site-level Synthesis, Regional/Continental Synthesis 29: Continuous Measures of Net Ecosystem Carbon Exchange and Gross Primary Productivity for the conterminous United States Derived from MODIS and AmeriFlux Data

29: Continuous Measures of Net Ecosystem Carbon Exchange and Gross Primary Productivity for the conterminous United States Derived from MODIS and AmeriFlux Data Jingfeng Xiao, Pennsylvania State University, jing@psu.edu (Presenting) Qianlai Zhuang, Purdue University, qzhuang@purdue.edu The AmeriFlux network provides continuous observations of ecosystem level exchange of carbon dioxide for a variety of ecosystem and climate types across North America, Central America, and South America. However, these eddy flux measurements only represent the carbon fluxes at the scale of the tower footprint. There is growing interest in scaling up eddy flux measurements to regional or continental scales for the diagnoses and attribution of carbon sources/sinks. Here we used satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) to upscale net ecosystem carbon exchange (NEE) and gross primary productivity (GPP) derived from AmeriFlux towers to the continental scale. We combined MODIS data and AmeriFlux data for 42 towers involving a variety of vegetation types (e.g., forests, grasslands, shrublands, savannas, and croplands) to develop predictive NEE and GPP models using piecewise regression models. We trained and evaluated these models using AmeriFlux data over the periods 2000-2004 and 2005-2006, respectively. We found that the models predicted NEE and GPP fairly well at the site level. We then applied the models to the continental scale and predicted NEE and GPP for each 1km by 1km cell across the conterminous U.S. for each 8-day interval over the period 2000-2006. Our models generally captured the expected spatial and temporal patterns of NEE and GPP. Our estimates provided independent datasets from model simulations, and could be valuable data for constraining the U.S. carbon budget and examining the impacts of climate variability, extreme climate events, and disturbances on terrestrial carbon cycling. Our study also indicated that the AmeriFlux network should be augmented by establishing more towers in the western U.S. and for certain vegetation types such as open shrublands and savannas and more towers representing early stages following disturbances in order to reduce the uncertainties associated with our NEE and GPP estimates. Keywords: Diagnosis, Attribution 30: Assessment of the impacts of biofuel crops on the carbon, water, and nitrogen cycles in Central Illinois

30: Assessment of the impacts of biofuel crops on the carbon, water, and nitrogen cycles in Central Illinois Marcelo Zeri, Energy Biosciences Institute, mzeri@illinois.edu (Presenting) Andrew VanLoocke, Energy Biosciences Institute, andyvanl@atmos.uiuc.edu George Hickman, Energy Biosciences Institute, ghickma2@illinois.edu Carl Bernacchi, Department of Plant Biology and, Institute of Natural Resources Sustainability, bernacch@illinois.edu Eddy covariance measurements of CO2 and water vapor fluxes are performed over four agricultural plots in Central Illinois in order to assess the environmental impacts of biofuel crops on the cycles of water, carbon, and nitrogen. The species chosen are Maize (Zea mays), Giant Miscanthus (Miscanthus x giganteus), Switchgrass (Panicum virgatum) and a mixture of native prairie varieties. Maize is extensively planted in the Midwestern US and its yields are mostly used for food. The potential diversion of parts of these yields for ethanol production has fueled the debate about rising food prices. Alternative non-food crops as Giant Miscanthus and Swithgrass are promising options for mass-production of ethanol. However, the impacts of such crops on the environment have to be assessed before their implementation on extensive agricultural areas. Measurements of soil respiration as well as estimates of soil organic carbon content are conducted in order to complement the eddy covariance measurements in the calculations of net primary production (NPP) and net ecosystem production (NEP) for each plot. Additionally, the net biome production (NBP) will be estimated by including the carbon exported as harvested biomass. Other greenhouse gases (GHG) as N2O and methane are going to be measured by the use of a tunable diode laser (TDL) analyzer. The fields were established during the summer of 2008 and preliminary results show a similar CO2 flux (FC) daily cycle for Switchgrass and Prairie while Miscanthus has a lower uptake due to its young and still sparse canopy. The comparison between the different species will continue for several growing seasons as it is expected a maximum yield for Miscanthus within three to four years. Keywords: Diagnosis, Site-level Synthesis

Attribution Posters 31: Quantifying Changes in High Latitude Ecosystems of Alaska and Northeastern Russia in Response to Climate and Fire Disturbance

31: Quantifying Changes in High Latitude Ecosystems of Alaska and Northeastern Russia in Response to Climate and Fire Disturbance Scott J Goetz, Woods Hole Research Center, sgoetz@whrc.org Michelle Mack, University of Floria, mcmack@ufl.edu James T Randerson, University of California, Irvine, jranders@uci.edu Yufang Jin, University of California, Irvine, yufang@uci.edu Pieter Beck, Woods Hole Research Center, pbeck@whrc.org (Presenting)

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We will provide an overview of our recent NACP project focused on better quantifying the climate impacts of a changing boreal fire regime using satellite remote sensing integrated with ecosystem models and field measurements. Our primary objective is to reduce carbon cycle uncertainties and improve understanding of ecosystem responses to environmental change, using both observations and models across gradients of disturbance. We are specifically interested in quantifying how tradeoffs associated with carbon and radiation fluxes vary with time since fire in boreal forest. This research is in the context of increased fire disturbance extent and frequency over the last several decades. Although an increase in fire activity leads to a net release of carbon and thus contributes to climate warming, it is inseparably linked with changes in the stand age distribution and species composition of northern forests. These shifts in species composition, in turn, have the potential to influence regional climate via suite of biophysical mechanisms, including via their effects on spring and summer albedo and rates of surface conductance and evapotranspiration. Thus, an integrated analysis of carbon accumulation and surface energy fluxes over successional cycles is necessary for managing northern forests to slow climate warming. This is challenging because of the multiple pathways that fires influence vegetation succession. A strong deciduous phase in the intermediate stage of succession, for example, may simultaneously increase surface albedo and rates of biomass accumulation during the first few decades after fire. In contrast, in a conifer-dominated successional trajectory, a post-fire increase in surface albedo may be smaller and carbon may accumulate at a slower rate. To the degree that burn severity regulates the establishment of conifer and deciduous tree species within burn perimeters, it plays a critical role in determining the long-term impacts of fire on northern climate. Keywords: Diagnosis, Attribution 32: Changes in boreal forest growth from the ground up: relating boreal tree growth to remotely sensed photosynthetic activity

32: Changes in boreal forest growth from the ground up: relating boreal tree growth to remotely sensed photosynthetic activity Pieter Beck, Woods Hole Research Center, pbeck@whrc.org (Presenting) Scott Goetz, Woods Hole Research Center, sgoetz@whrc.org Claire Alix, University of Alaska Quaternary Center, fncma@uaf.edu Glenn Juday, University of Alaska Fairbanks, g.juday@uaf.edu Andy Bunn, Western Washington University, andy.bunn@wwu.edu Andrea Lloyd, Middlebury College, lloyd@middlebury.edu Continental scale remote sensing and ecosystem modeling have revealed a decline in photosynthetic activity and net primary production over about 20% of North American boreal forest in the past 25 years. We compare these observations to stand-level observations and production models of tree growth in Alaska, an area with broad scale productivity declines, as well as with a circumpolar tree-ring database. In six mature, productive White Spruce stands, NDVI observations derived from 8 km GIMMS-AVHRR were positively correlated with average tree-ring widths (r ≤ 0.75 between 1982-2006), and both captured systematic trends as well as interannual variability. The relationship was less well defined in 3 black spruce stands, which had less dense canopy cover. In the productive white spruce forests, the covariation of NDVI and tree rings was high even in periods of drought, when ring widths are decoupled from temperature indices. Productivity estimates, generated using the BIOME-BGC model at some of the sites, were also consistent with the trends in the tree-ring and NDVI data. Time series analysis indicated the current year’s NDVI correlated well with the current year tree-ring widths, but even better with the following year (lag +1). This is in agreement with the more rapid response of photosynthetic activity to favorable conditions compared to growth, which in spruce depends largely on stored reserves. Trees are typically selected for ring sampling in sites where they are most likely to be sensitive to climate, such as ecotones, rather than to be representative of stand-level productivity, which was the criterion we were most interested. Nevertheless, trends in tree-ring widths in North America and Russia, compiled in the World Data Center for Paleoclimatology, weakly reflect the observed trends in growing season productivity from 1982 to 2006 when the forest-cover at the site is accounted for. Keywords: Attribution 33: An Estimate of the Tree Carbon Sink Due to Fire Reduction in California Montane Conifer Forests.

33: An Estimate of the Tree Carbon Sink Due to Fire Reduction in California Montane Conifer Forests. Jim Bouldin, UC Davis, jrbouldin@ucdavis.edu (Presenting) I present data on tree carbon (C) changes due solely to fire suppression over a 93 year period from a never-logged, mid-montane (1370 to 2130 m) landscape in California. Fire reduction policies are globally widespread and cause large changes in natural disturbance regimes. Hence, they should affect C accrual rates, but there is uncertainty in both modeling- and empirically-based estimates on the rate, and sometimes even the sign thereof, due to a lack of high quality data and to the confounding by logging or other ecological changes. Literature-based mean pre-1870 fire return intervals in the region were on the order of 8 to 20 years, but declined precipitously afterwards. The area was originally sampled without bias in 1911, and in 2004 I randomly re-sampled 20 large (1.6 ha) plots in the area. I found very large increases in tree density and tree C, with mean tree densities increasing in each of 13 diameter classes. Total density increased from 54 to 289 trees per ha (530 percent); the smallest diameter class increased 1100 percent while progressively larger classes had smaller relative increases. Allometrically estimated increases in tree C across the size classes were more uniform, and total tree C, excluding fine roots, increased from 100 to 228 Mg C per ha. These values very likely underestimate ecosystem C gain in response to fire reduction, because likely increases in snags, down logs, small trees, shrubs, and forest litter and duff are not included. Also, sheep grazing likely hampered regeneration in the few decades following initial fire declines, and recent controlled burns in 65 percent of the plots have likely reduced C levels somewhat. In many Sierran locations, controlled burns are now quite risky due to increased fuel loads and the consequent risk of historically unnatural catastrophic crown fires. Such fires instantly release very high C amounts and continue to emit C for many years due to dead wood decomposition and increased soil respiration. There is also a substantial risk of permanent conversion to shrub dominated systems in a warmer dryer climate, as forests and shrublands comprise a climatically-determined unstable equilibrium in the Sierra. These results are important relative to GHG reduction and land management policies in landscapes naturally prone to burning. Keywords: Diagnosis, Attribution 34: High temporal density change detection with Landsat imagery to quantify juniper expansion in eastern Oregon

34: High temporal density change detection with Landsat imagery to quantify juniper expansion in eastern Oregon John Campbell, Dept of Forest Science, Oregon State Univ., john.campbell@oregonstate.edu (Presenting)

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Robert Kennedy, Dept of Forest Science, Oregon State Univ., robert.kennedy@oregonstate.edu David Azuma, Forest Science Laboratory, U.S. Forest Service, dazuma@fs.fed.us Rick Miller, Dept of rangeland ecology and management, richard.miller@oregonstate.edu Warren B. Cohen, Forest Science Laboratory, U.S. Forest Service, warren.cohen@oregonstate.edu The expansion of western juniper (Juniperus occidentalis) into grassland and shrubland communities, as well as its densification within juniper woodlands, is a wide-spread phenomenon throughout eastern Oregon and elsewhere in the North American Great Basin. Traditional two-date image change detection is of limited use in mapping patterns and rates of these processes due to the slow rate of change and subsequent low signal to noise ratio. However, detection of spectral trends over 24 years of annual Landsat imagery shows promise for mapping change in juniper cover. Twelve-percent of nearly 4,000 points in eastern Oregon known to contain juniper show detectable increases in TM tassel cap wetness, an index also shown to be correlated with percent juniper cover across the same region. Given strong relationships between juniper cover and woody biomass, we suggest that high temporal density change detection using wetness, and other reflectance indices associated with juniper crown cover may prove very useful in quantifying the changes in carbon stocks associated with woody encroachment throughout the North American Great Basin. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 35: Quantifying the influence of climate and land use change on primary production using carbonyl sulfide measurements

35: Quantifying the influence of climate and land use change on primary production using carbonyl sulfide measurements John Elliott Campbell, University of California, Merced, ecampbell3@ucmerced.edu (Presenting) Joe A. Berry, Carnegie Institution of Washington, jberry@ciw.edu Process-level information is urgently needed to reduce uncertainty in carbon-climate parameterizations for climate forecasting. However, we lack robust tools for addressing the NACP goal of measuring primary production and respiration fluxes at large-scales (> 10^4 km^2). Recent developments of carbonyl sulfide (COS) as a primary production tracer may provide a needed constraint for process-level information. Our objective is to quantify variations in primary production caused by climate anomalies or caused by recent land use change driven by biofuels demand. Our approach integrates existing land use products and airborne COS measurements with new surface COS-CO2 measurements and primary production estimates from ecosystem models. Keywords: Attribution 36: Disturbance and Carbon Fluxes of Canadian Forests

36: Disturbance and Carbon Fluxes of Canadian Forests Carole Coursolle, Université Laval, Carole.Coursolle@sbf.ulaval.ca (Presenting) Hank A. Margolis, Université Laval, Hank.Margolis@sbf.ulaval.ca Marc-André Giasson, Université Laval, Marc-Andre.Giasson@sbf.ulaval.ca Operational Science Committee, Canadian Carbon Program, fluxnet.canada@sbf.ulaval.ca Net ecosystem productivity (NEP), gross ecosystem productivity (GEP) and ecosystem respiration (ER) of 24 forest stands across Canada were evaluated using the eddy covariance technique over a three-year period (2004-2006) for 14 black spruce, four jack pine, three Douglas fir stands and one each of aspen, mixed-wood forest and white pine ranging in age from 2- to 170-years old. Canadian forests are generally carbon sources until about 20 years of age, weak to moderate sinks (45 - 300 g C m-2 yr-1) from 20 to 80 years of age and carbon neutral or weak sinks (11 - 44 g C m-2 yr-1) thereafter. Using these data, we estimate that forest stands in Canada would lose, on average, approximately 21t C ha-1 during the first 20 years of regrowth after a disturbance, offset this initial loss after approximately 43 years, and show a net gain of 69t C ha-1 at 90 years of age. The GEP growing season length increased with increasing age until about 20 years, which coincided with a switch from carbon source to sink. Annual ecosystem respiration of the youngest sites in the study was 1.3 to 3.3 times greater than annual photosynthesis (GEP) while the strongest sinks had annual GEP rates that were only 1.1 to 1.4 times greater than ER. After accounting for the effects of LAI, mean daily minimum soil temperatures, GEP season length and daily maximum soil temperatures were the growing season meteorological variables that had the greatest effect on the GEP of mature (74-170 years old), intermediate-aged (23-67 years old) and young, recently-disturbed stands (2-18 years old), respectively. Keywords: Attribution, Prediction, Regional/Continental Synthesis 37: Modelling of hydrological and thermal controls on carbon dioxide exchange at Mer Bleue bog

37: Modelling of hydrological and thermal controls on carbon dioxide exchange at Mer Bleue bog Dimitre D. Dimitrov, University of Alberta, dimitre@ualberta.ca (Presenting) Robert F. Grant, University of Alberta, robert.grant@afhe.ualberta.ca Elyn Humphreys, Carleton University, elyn_humphreys@carleton.ca The main purpose of this research, achieved by means of the process-based modelling, was to understand the effects of hydrological and thermal controls on bog net ecosystem productivity and its components. Preferential gravitational flow through high macropore fractions of the fibric peat, complementary to the matrix flow, explained well its rapid water infiltration and low water retention. Hummocky microtopography influenced peat temperatures at depth and ground heat fluxes at surface by inducing natural air convection in well-drained macroporous fibric peat of hummock mounds. This natural air convection, driven by temperature differences between hummock surface and interior, enhanced heat transfer in hummocks and also in neighbouring hollows. Water table drawdowns induced drying in the macroporous near-surface hummock peat that resulted in decrease of the near-surface microbial respiration, which offset increased microbial and root respiration at depth with improved aeration. Furthermore, increased hollow soil respiration with water table drawdowns was offset by decreased moss aboveground respiration at hummocks with near-surface drying. So, ecosystem respiration at Mer Bleue bog was found conservative to subsurface hydrology. Vascular gross primary productivity was little affected by subsurface hydrology during dry periods of low water tables as vascular roots extended below the zone of near-surface desiccation. However, near-surface desiccation caused decrease in moss gross primary productivity and thus in bog gross primary productivity. With conservative response of ecosystem respiration, subsurface hydrology affected net

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ecosystem productivity mainly through gross primary productivity at Mer Bleue bog. The water table and near-surface peat water contents were some of the most important factors in explaining bog net ecosystem productivity and its interannual variability. Keywords: Attribution 38: pCO2 observations from the British Columbia and Alaska coastal margin

38: pCO2 observations from the British Columbia and Alaska coastal margin Wiley Evans, COAS/OSU, wevans@coas.oregonstate.edu (Presenting) Burke Hales, COAS/OSU, bhales@coas.oregonstate.edu Peter Strutton, COAS/OSU, strutton@coas.oregonstate.edu The role of North American continental margins in the exchange of CO2 with the atmosphere is essentially unknown, the result of a near cancellation of large, poorly-constrained fluxes into the ocean in northern regions and large, poorly-constrained fluxes out of the ocean in southern regions. One important region where few measurements of seawater pCO2 exist is the coastal margin of British Columbia and Alaska, which had been presumed to be a large sink for atmospheric CO2. Here we present results from the first of a series of underway pCO2 surveys dedicated toward resolving the seasonal cycle of air-sea CO2 exchange on this important coastal margin. The data from this Fall 2008 survey demonstrate pCO2 variability from 280 µatm to 600 µatm. Underway temperature, salinity and chlorophyll data also point to the importance of fresh water inputs and biological activity in shaping the spatial distribution of pCO2. Keywords: Diagnosis, Attribution 39: Monitoring of gross primary productivity of crops using Landsat data

39: Monitoring of gross primary productivity of crops using Landsat data Anatoly A Gitelson, University of Nebraska-Lincoln, agitelson2@unl.edu (Presenting) Andrés Viña, Michigan State University, vina@msu.edu Jeffrey G Masek, NASA Goddard Space Flight Center, lmasek@unlnotes.unl.edu Shashi B Verma, University of Nebraska-Lincoln, sverma@unlnotes.unl.edu Andrew E Suyker, University of Nebraska-Lincoln, asuyker@unlnotes.unl.edu There is a growing interest in monitoring the gross primary productivity (GPP) of crops due mostly to their carbon sequestration potential. In this paper we presented a new technique for GPP estimation in rainfed and irrigated maize and soybeans based on the close and consistent relationship between GPP and crop chlorophyll content, and entirely on remotely sensed data. A recently proposed Chlorophyll Index, that involves green and NIR spectral bands, was used to retrieve GPP from Landsat ETM+ data. Due to its high spatial resolution (i.e., 30x30m/pixel), this satellite system is particularly appropriate for detecting not only between but also within field GPP variability during the growing season. The Chlorophyll Index obtained using atmospherically corrected Landsat ETM+ data was found to be linearly related with crop GPP: root mean squared error of less than 1.58 g C m-2d-1 in a GPP range of 1.88 g C m-2d-1 to 23.1 g C m-2d-1, therefore, it constitutes an accurate surrogate measure for GPP estimation. For comparison purposes, other vegetation indices were also tested. These results open new possibilities for analyzing the spatio-temporal variation of the GPP of crops using the extensive archive of Landsat imagery acquired since the early 1980s. Keywords: Attribution, Site-level Synthesis, Regional/Continental Synthesis, MCI Synthesis 40: Quantifying Organic and Mineral Soil Carbon Turnover Along Climate Gradients: The EBIS-AmeriFlux Project

40: Quantifying Organic and Mineral Soil Carbon Turnover Along Climate Gradients: The EBIS-AmeriFlux Project Paul J. Hanson, Oak Ridge National Laboratory, hansonpj@ornl.gov (Presenting) Karis McFarlane, Lawrence Livermore National Laboratory, mcfarlane3@llnl.gov Susan E. Trumbore, University of California - Irvine, setrumbo@uci.edu Tom Guilderson, Lawrence Livermore National Laboratory, tguilderson@llnl.gov Margaret S. Torn, Lawrence Berkeley National Laboratory, mstorn@lbl.gov Roser Matamala, Argonne National Laboratory, matamala@anl.gov Julie Jastrow, Argonne National Laboratory, jdjastrow@anl.gov Mac A. Callaham, US Forest Service, mcallaham@fs.fed.us William J. Parton Jr., Colorado State University, billp@nrel.colo.edu EBIS-AmeriFlux Site Operators, Various, various Interannual dynamics of litter and soil C pools are not well defined. Data are available on CO2 efflux from soils, but the net effect of these fluxes on C stocks residing in soils is seldom quantified. Interannual variation in flux from the soil suggests transient changes in the soil C stocks, but the current capability to detect change in these stocks is limited. The EBIS-AmeriFlux Project is using unique 14C-enriched materials to characterize the rate of C flux from litter sources to mineral soil sinks over a range of climatic and biological conditions. We are quantifying (1) leaf litter to mineral soil transfers using enriched litter at 901‰ within replicated 2 x 2m plots, (2) Oa (humus) to mineral soil transfers using enriched humus at 726‰ within replicated 1 x 1m plots, and (3) root litter to mineral soil transfers using enriched root material at 523‰ added to constructed root cores for periodic retrieval. All background-enriched materials collected on the Oak Ridge Reservation, Tennessee were irradiated (sterilized) prior to being applied to each site. The project is addressing a range of hypotheses at the following study sites with the help local site operators: Cold Sites - University of Michigan Biological Station and Bartlett Experimental Forest, New Hampshire; Intermediate Temperature Site - Harvard Forest, Massachusetts; Warm sites - MOFlux AmeriFlux Site, Missouri and the EBIS-Oak Ridge project sites were completed work will be used as additional warm reference sites for climate gradient analyses. The project is underway. Time-zero sampling and initial 14C-enriched materials were added in November and December of 2007. Initial site characterization shows that carbon stocks and 14C-signatures show somewhat similar depth profiles, but strong regional differences. Younger carbon with depth at the Michigan site is attributed to the coarser texture of soil at this site. Long-term goals of this work will be to produce mechanistic models of the soil carbon cycle across sites capable of distinguishing climate, edaphic, and biological controls on the pathways, rate and fate of isotopically labeled materials in the respective soils. Keywords: Attribution

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41: Quantifying Soil Carbon Cycle Mechanisms and Flux Using 14C-Enriched Leaf Litter Manipulations: Implications for Modeling Carbon In Soil

41: Quantifying Soil Carbon Cycle Mechanisms and Flux Using 14C-Enriched Leaf Litter Manipulations: Implications for Modeling Carbon In Soil Paul J. Hanson, Oak Ridge National Laboratory, hansonpj@ornl.gov (Presenting) Mats J. Froberg, Sveriges Lantbruksuniversitet, mats.froberg@sml.slu Chris Swanston, US Forest Service, cswanston@fs.fed.us Susan E. Trumbore, University of California - Irvine, setrumbo@uci.edu Margaret S. Torn, Lawrence Berkeley National Laboratory, mstorn@lbl.gov Julie Jastrow, Argonne National Laboratory, jdjastrow@anl.gov Tom Guilderson, Lawrence Livermore National Laboratory, tguilderson@llnl.gov William J. Parton, Colorado State University, billp@nrel.colo Near-background releases of 14CO2 from waste incinerators on or near the Oak Ridge Reservation (N 35° 58'; W 84°16') provided the opportunity for observations of the soil carbon (C) cycle at ecosystem scales. Multi-year manipulations of enriched litter additions were developed as a part of the Enriched Background Isotope Study (EBIS). The EBIS experiments included (1) a multi-year, enriched-leaf-litter addition study for tracking annual movement of labeled C for a full range of soil depths and chemical forms, and (2) a mesocosm-based study with intra-annual resolution to follow the fate of leaf-litter-derived 14C-enriched material to dissolved organic C, organic and soil C pools, and CO2 release. After one year of enriched (1005‰) or background (221‰) litter additions there was little evidence of new C movement below the Oi horizon. 14C-signatures with enrichment or dilution patterns did develop within the Oe/Oa horizon after three years of treatments, and continued to develop as the enriched cohorts migrated downwards. Five years after the initial leaf-litter cohort additions, there was little evidence for a net change in the 14C-enrichment of bulk mineral soils. Large soil C stocks and unenriched root turnover C sources may mask small changes from enriched litter additions. Annual time step resolution litter-manipulations did reveal dissolved organic carbon (DOC) as a rapid mechanism for transferring surface C deep into the mineral soils. However, the annual net amount of DOC retained between 15 and 70 cm was quite small (1.5 to 6 g m-2 y-1). Mesocosm observations showed extensive short-term retention of DOC does occur in the A horizon, but it was rapidly respired back to the atmosphere within an annual cycle. These combined conclusions demand the addition of new structural and functional details to common biogeochemical cycling models (e.g., DayCent), and such changes are in progress. Keywords: Attribution, Site-level Synthesis 42: Daily emissions of CO2, CO and CH4 from biomass burning in the United States in 2006 and 2007 and the impact on North American carbon cycle

42: Daily emissions of CO2, CO and CH4 from biomass burning in the United States in 2006 and 2007 and the impact on North American carbon cycle Wei Min Hao, U.S. Forest Service, RMRS Fire Sciences Laboratory, whao@fs.fed.us (Presenting) Shawn P. Urbanski, U.S. Forest Service, RMRS Fire Sciences Laboratory, surbanski@fs.fed.us Bryce L. Nordgren, U.S. Forest Service, RMRS Fire Sciences Laboratory, bnordgren@fs.fed.us Alex Petkov, University of Montana, apetkov@fs.fed.us We will present daily emission inventories of CO2, CO, and CH4 from biomass fires in the continental United States at a 1-km x 1-km resolution from January 2006 to December 2007. The estimates are based on (1) MODIS data for detecting active fire locations and mapping burned areas, (2) land cover and land use maps, (3) meteorological analyses, (4) models of fuel condition, fire behavior, and fuel consumption, and (5) ecosystem specific emission factors for CO2, CO, and CH4. The spatial and temporal pattern of fire emissions for 2006 and 2007 are similar. The emission sources from biomass burning started in Florida, Georgia, North Carolina, and South Carolina in the southeastern U.S. in January. The fire activity and associated emissions then progressed westward across the southern U.S. in the spring, reaching Arizona and New Mexico in May. From the southwestern U.S., the fire activity and emissions extended northward through the intermountain west, reaching Idaho and Montana in August and September. We will compare quantitatively the extent of fire emission sources with emission sources from fossil fuel combustion seasonally for various regions in the continental United States. The results are essential in understanding the role of biomass burning in modulating daily, seasonal, and annual trends in atmospheric CO2 across the continental United States. Keywords: Diagnosis, Attribution, Decision Support, Regional/Continental Synthesis, non-CO2 Greenhouse Gases Synthesis 43: Assessing the impacts of bark beetle outbreaks on carbon budgets in the western United States

43: Assessing the impacts of bark beetle outbreaks on carbon budgets in the western United States Jeffrey A. Hicke, University of Idaho, jhicke@uidaho.edu (Presenting) Eric Pfeifer, University of Idaho, eric.pfeifer@vandals.uidaho.edu Arjan J.H. Meddens, University of Idaho, arjan.meddens@vandals.uidaho.edu Ryan Sheridan, University of Idaho, rsheridan@vandals.uidaho.edu Bark beetle outbreaks kill millions of trees across North America and affect a similar amount of area annually as wildfire. A recent study showed that a major insect infestation in British Columbia caused forests there to act as carbon sources to the atmosphere for decades beyond the outbreak. Additional studies focused on the US and more detailed studies to reduce uncertainties are needed to improve the understanding of the role of these insect epidemics in the global carbon cycle. Here, we report on several research activities investigating bark beetle outbreaks and carbon budgets. 1) We are developing the means of mapping and monitoring tree mortality caused by insects for detailed landscape studies using very fine spatial-resolution satellite imagery as well as continental-scale studies using coarse-resolution imagery. 2) We are establishing which climate and stand condition mechanisms are most important for driving outbreaks, and we are modeling future outbreak regimes in response to projected climate change. 3) We are quantifying the impact of bark beetle outbreaks on local to regional carbon budgets in the western United States through field observations, forest inventories, forest stand modeling, and remote sensing. We illustrate examples of research from each topic as they relate to the North American Carbon Program. Keywords: Diagnosis, Attribution

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44: Remote Sensing of Vegetation Light Use Efficiency Dynamics

44: Remote Sensing of Vegetation Light Use Efficiency Dynamics Karl Fred Huemmrich, University of Maryland Baltimore County, karl.f.huemmrich@nasa.gov (Presenting) Elizabeth M. Middleton, NASA Goddard Space Flight Center, Elizabeth.m.middleton@nasa.gov Lawrence A. Corp, SSAI, lawrence.a.corp@nasa.gov Yen-Ben B. Cheng, NASA, Yen-Ben.Cheng@nasa.gov Petya K. Entcheva Campbell, University of Maryland Baltimore County, pcampbel@pop900.gsfc.nasa.gov Qingyuan Y. Zhang, University of Maryland Baltimore County, qingyaun@umbc.edu Andrew L. Russ, USDA, andrew.russ@ars.usda.gov William P. Kustas, USDA, bill.kustas@ars.usda.gov John H. Prueger, USDA, john.prueger@ars.usda.gov Describing carbon cycle dynamics at global or continental scales requires accurate descriptions of spatial and temporal patterns of photosynthetic CO2 uptake. Current approaches determining ecosystem carbon exchange typically use estimates from models incorporating meteorological data to predict responses to environmental conditions (e.g., drought, high/low temperatures). However, these approaches assume maximum efficiency and environmental stress responses are consistent per biome, even as climate and atmospheric CO2 concentrations change. Associated with photosynthetic down-regulation are changes in leaf apparent spectral reflectance. Stress induced spectral responses include concentration changes of xanthophyll cycle pigments, detected using Photosynthetic Reflectance Index (PRI), and chlorophyll fluorescence. This study examines ecosystem photosynthetic light use efficiency (LUE) using reflectance changes associated with physiologic stress responses. Data were collected for corn at the USDA Beltsville Agricultural Research Center Optimizing Production Inputs for Economic and Environmental Enhancement (OPE3) fields. Throughout 11 days in the 2008 growing season, multiple measurements were collected describing carbon exchange and spectral reflectance, including: hyperspectral reflectance of field transects; leaf level hyperspectral optical properties, carbon exchange, fluorescence, and chlorophyll and carotenoid contents; soil moisture, and fraction absorbed photosynthetically active radiation. Agricultural Research Service researchers measured CO2 flux using eddy covariance. We examined scaling of both reflectance and carbon exchange from leaf to canopy and developed links between vegetation reflectance and carbon exchange. Narrow band and hyperspectral data can detect changes in leaf and canopy reflectance through a day and through the growing season, which are related to LUE from cornfield carbon flux data. Successful reflectance indices include PRI and solar induced fluorescence from Fraunhofer Line Discrimination. The results highlight the importance of frequently measured hyperspectral data to detect physiological changes in vegetation, suggesting the need to develop methods for measuring sites frequently, with vegetation stress directly assessed with reflectance-based bio-indicators avoiding reliance on models using assumed values.

Keywords: Attribution, Site-level Synthesis 45: Will Elevated Atmospheric CO2 Change Soil Carbon Stocks in Tilled Corn-Soybean Rotation Agroecosystems of the U.S. Midwest?

45: Will Elevated Atmospheric CO2 Change Soil Carbon Stocks in Tilled Corn-Soybean Rotation Agroecosystems of the U.S. Midwest? Kelly K. Moran, Argonne National Laboratory, moran@anl.gov Julie D. Jastrow, Argonne National Laboratory, jdjastrow@anl.gov (Presenting) The capability of agricultural soils to serve as significant C sinks that can help offset rising atmospheric CO2 concentrations is uncertain. The potential for storing additional C in U.S. Midwest soils is large because long-term cultivation has depleted the substantial soil organic matter (SOM) stocks that once existed in the native grassland and forest ecosystems of the region. Yet, it is unclear if responses of rowcrop agroecosystems to rising atmospheric CO2 will alter residue inputs or decomposition rates sufficiently to cause a net change in soil C stocks. In central Illinois, free-air CO2 enrichment (FACE) technology was used to investigate the effects of elevated CO2 on soil C pools in a tilled corn-soybean rotation system. After 5 and 6 y of CO2 enrichment (following soybean and corn, respectively), we investigated the distribution of C among soil fractions believed to vary in their ability to protect SOM from rapid decomposition. None of the isolated soil C pools, nor the bulk soil C, showed any significant differences between the ambient- and elevated-CO2 treatments. Comparisons to pretreatment soils suggest that overall the site has lost soil C from unprotected pools regardless of CO2 treatment since the experiment’s inception. Soil C in microaggregate-protected pools remained unchanged throughout the study. These findings suggest that tillage and other management practices employed during the experiment have had a greater effect on soil C than the CO2 treatments. Apparently, the disturbance associated with tillage, coupled with the high fertility of the site, have precluded any significant soil C response to the increased C inputs resulting from atmospheric CO2 enrichment. Keywords: Attribution 46: Incorporation of Root and Surface Litter Inputs Into Soil C Pools: What Do Different Physical Fractionation Approaches Tell Us?

46: Incorporation of Root and Surface Litter Inputs Into Soil C Pools: What Do Different Physical Fractionation Approaches Tell Us? Julie D. Jastrow, Argonne National Laboratory, jdjastrow@anl.gov (Presenting) Christopher W. Swanston, U.S. Forest Service Northern Research Station, cswanston@fs.fed.us Sarah L. O'Brien, University of Illinois at Chicago, sobrie1@uic.edu Kelly K. Moran, Argonne National Laboratory, moran@anl.gov Rachel C. Porras, Lawrence Berkeley National Laboratory, rcporras@lbl.gov Margaret S. Torn, Lawrence Berkeley National Laboratory, mstorn@lbl.gov Paul J. Hanson, Oak Ridge National Laboratory, hansonpj@ornl.gov Efforts to isolate soil C pools related to the structure, function and turnover of soil organic matter (SOM) often employ physical fractionation methods. Both density-based and particle-size fractionations have been used to examine the role of aggregates in SOM cycling and stabilization. After a 14C pulse labeling of deciduous forest, reciprocal transplants of enriched vs. near-background litter allowed us to track the source and dynamics of SOM pools isolated by both fractionation approaches. Light fraction (LF) and particulate organic matter (POM)

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were separated into unprotected and aggregate-protected pools by applying different dispersion energies. The mineral-associated pool was characterized either as the dense fraction (DF) or as particles <53 µm (MOM). We used procedural constraints and the distributions of bulk soil C and 14C to compare pools isolated by each method. The unprotected POM fraction included both free and macroaggregate-associated particulate C pools, whereas the free LF isolated mostly unprotected, interstitial particulate C. Operationally, the occluded POM fraction consisted of microaggregate-protected particulate C, but the occluded LF included both macroaggregate-associated and microaggregate-protected C. Overall, POM accounted for 5% more of bulk soil C than LF, with the difference likely due to inclusion of some microaggregate-protected particulate C in the DF. POM/LF-C dynamics associated with root turnover occurred mostly at the macroaggregate rather than the microaggregate scale during the 4-y study. In contrast, the dynamics of litter C sources occurred at both scales suggesting a different mode of incorporation, e.g., sorption of soluble C to exchange sites or assimilation by microbes associated with the POM/LF. Acid hydrolysis of the MOM fraction revealed dynamic components that rapidly incorporated and cycled C inputs from both root and litter sources. Taken together, the results improve our understanding of short-term soil C dynamics and the C pools isolated by physical fractionation methods. Keywords: Attribution 47: Hierarchical Controls on the Accrual of Physically Protected Soil Carbon Pools Following Tallgrass Prairie Restoration

47: Hierarchical Controls on the Accrual of Physically Protected Soil Carbon Pools Following Tallgrass Prairie Restoration Sarah L. O'Brien, University of Illinois at Chicago, sobrie1@uic.edu Julie D. Jastrow, Argonne National Laboratory, jdjastrow@anl.gov (Presenting) Miquel A. Gonzalez-Meler, University of Illinois at Chicago, mmeler@uic.edu Long-term cultivation has depleted the soil C stocks that developed under native ecosystems. The ability of soils to regain this lost C following reestablishment of perennial ecosystems is constrained by plant inputs, soil properties, and environmental conditions. However, internal soil mechanisms governing the dynamics of accruing soil C stocks are poorly understood. Most temperate soils appear to have a finite capacity to protect soil organic matter (SOM) from mineralization, which may limit their potential C sink strength. We investigated how physical protection by hierarchical soil aggregate structure affects the rate of soil C accumulation in restored tallgrass prairie and determined whether these protection mechanisms become saturated despite continuing C inputs. We used a chronosequence approach and exponential modeling to (1) assess the dynamics of 12 distinct SOM pools distributed within four aggregate protection classes [particulate organic matter (POM), silt, and clay from non-aggregated soil, macroaggregates, microaggregates-within-macroaggregates, and free microaggregates] and (2) quantify the relative contributions of these pools to soil C accrual. Aggregate mass rapidly returned to pre-cultivation levels, but aggregate-protected C took longer to recover. The rates of C accrual varied significantly among the measured fractions, suggesting that some pools reach steady state faster than others or that the protective capacity of some pools saturates while other pools continue to accrue C. Most of the C accrual occurred in the silt-sized fraction from microaggregates-within-macroaggregates. The clay-sized fractions from all aggregate classes contributed the least to soil C accumulation. The POM from non-aggregated soil accrued slowly but continually, suggesting that C builds in relatively unprotected pools even after soil protective mechanisms approach steady state or saturation. Our results improve understanding of internal soil C dynamics and the capacities of SOM protection mechanisms and will contribute to the next generation of SOM and ecosystem C models. Keywords: Attribution 48: Soil Carbon and Nitrogen Dynamics in a Deciduous Forest Exposed to Ten Years of Atmospheric CO2 Enrichment

48: Soil Carbon and Nitrogen Dynamics in a Deciduous Forest Exposed to Ten Years of Atmospheric CO2 Enrichment Julie D. Jastrow, Argonne National Laboratory, jdjastrow@anl.gov (Presenting) Kelly K. Moran, Argonne National Laboratory, moran@anl.gov Sarah L. O'Brien, University of Illinois at Chicago, sobrie1@uic.edu Thomas W. Boutton, Texas A&M University, boutton@neo.tamu.edu Plant responses to atmospheric CO2 enrichment, particularly above- vs. belowground allocation of net primary production, will affect soil organic matter dynamics and stocks. Even when significant changes in soil C are evident, predictions of the potential for long-term stabilization will require studies of C allocation and dynamics in functionally meaningful soil organic matter pools. At the free-air CO2 enrichment (FACE) experiment on a sweetgum plantation in Oak Ridge, Tennessee, we are using (1) repeated sampling over time, (2) the isotopic tracer provided by the depleted 13C signature of the fossil fuel source of CO2 used for fumigation, and (3) physicochemical fractionation procedures to determine the fate and dynamics of FACE-derived detritus inputs to soil organic matter. During the first 10 y of the experiment, soil C and N in the surface 5 cm accumulated at a linear rate in the elevated CO2 treatment. In contrast, C and N stocks in ambient soils remained unchanged for the first 5 y, but then increased between 5 and 10 y at rates approaching those in the elevated CO2 treatment, suggesting that the step function in CO2 enrichment may have caused transient accelerated soil responses in this aggrading forest plantation. Carbon and N accrual occurred in most soil fractions, and new FACE-derived C entered all fractions at varying rates. However, in addition to new C, conservation of existing organic matter appears to account for some of the C accrued in mineral-associated fractions. Beyond the CO2 treatment responses, the dynamic changes in this system, coupled with the isotopic tracer, will contribute to improved mechanistic understanding and quantitation of the processes involved in soil C cycling and stabilization required by soil organic matter simulation models. Keywords: Attribution 49: Controls on the spatial distribution of soil organic carbon in black spruce forests

49: Controls on the spatial distribution of soil organic carbon in black spruce forests Kristofer Johnson, University of Alaska-Fairbanks, USGS, ffkdj@uaf.edu (Presenting) David McGuire, University of Alaska-Fairbanks, USGS, ffadm@uaf.edu Shuhua Yi, University of Alaska-Fairbanks, ffsy@uaf.edu Jennifer Harden, USGS, jharden@usgs.gov Kristen Manies, USGS, kmanies@usgs.gov Boreal environments continue to be important to global carbon cycling, especially in the face of potential future climate changes. Perhaps the least understood component of carbon dynamics in these forests is the role and relative importance of the soil organic carbon (SOC) pool.

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Even within a single forest type (e.g. black spruce) differences in SOC contents can vary widely. One way to address SOC heterogeneity is to define landscape units based on first order controls such as soil drainage and aspect using non-parametric Multivariate Regression Trees (MRT, or ‘classification trees’). The resulting landscape-specific spatial models are especially useful when they can be reliably extrapolated to other locations. This approach was tested to see if two SOC datasets gathered from black spruce forests in Alaska and Manitoba could produce simple first order relationships that describe the spatial variation of SOC and that were similar between locations. The results demonstrate the utility of simple MRT-based spatial models to identify basic controls on SOC accumulations from biotic and topographic data. The relationships can be used to improve process-based modeling studies that consider different landscape units within a single forest type. Keywords: Attribution 50: Carbon Emissions from the 2004 Alaskan Fires

50: Carbon Emissions from the 2004 Alaskan Fires Eric S. Kasischke, University of Maryland, ekasisch@umd.edu (Presenting) Elizabeth Hoy, University of Maryland, elizabeth.hoy@gmail.com Merritt R. Turetsky, University of Guelph, mrt@uoguelph.ca Evan S. Kane, Michigan State University, kanee@msu.edu Roger D. Ottmar, U.S. Forest Service, rottmar@fs.fed.us William de Groot, Canadian Forest Service, bdegroot@nrcan.gc.ca Jennifer H. Harden, U.S. Geological Survey, jharden@usgs.gov Kristen Manies, U.S. Geological Survey, kmanies@usgs.gov Nancy H.F. French, Michigan Tech Research Institute, nancy.french@mtu.edu This paper presents the results of a NASA sponsored Cycle Science Project that focused on improving estimates of emissions from wildland fires that occur in boreal regions that contain ecosystems with deep organic soils. To improve our understanding of the level of burning of surface organic layers, field data were collected over four years, and then integrated with observations collected from previous studies. This resulted in a database that contained over 18,000 organic layer depth measurements, with ~3,000 samples being analyzed for bulk density and percent carbon. Analyses of these data have provided the ability to estimate pre- and post-fire organic layer carbon content as a function of depth for different topographic positions, which when combined, can be used to estimate carbon emissions. We then used this knowledge to modify the wildland fire emissions model developed by the Canadian Forest Service, BORFIRE. We used this model to estimate emissions from the 2004 fire season in Alaska (the largest on record, affecting some 2.7 million ha). This model uses fire weather indices derived from data collected at weather stations to estimate fuel consumption. Vegetation categories and burned area estimates included in the model were mapped using information products derived from Landsat TM/ETM+ data and MODIS data. Seasonal timing of fires was determined from MODIS hotspot data. When the Landsat information products were used, carbon emissions were significantly higher than estimated by our previous model (BWEM) and other researchers (GFED-2). Keywords: Attribution 51: Estimation of biennial forest disturbance rates for the conterminous United States

51: Estimation of biennial forest disturbance rates for the conterminous United States Robert E Kennedy, Department of Forest Ecosystems and Society, Oregon State University, robert.kennedy@oregonstate.edu (Presenting) Samuel N. Goward, Department of Geography, University of Maryland, sgoward@umd.edu Warren B. Cohen, Pacific Northwest Research Station, USDA Forest Service, wcohen@fs.fed.us Jeffrey G Masek, Biospheric Sciences Branch, NASA Goddard Space Flight Center, jeffrey.g.masek@nasa.gov Gretchen Moisen, Rocky Mountain Research Station, USDA Forest Service, gmoisen@fs.fed.us Chengquan Huang, Department of Geography, University of Maryland, cqhuang@umd.edu Karen Schleeweis, Department of Geography, University of Maryland, ska1@umd.edu Nancy Thomas, Department of Geography, University of Maryland, nthomas1@umd.edu Sean Healey, Rocky Mountain Research Station, USDA Forest Service, seanhealey@fs.fed.us Scott Powell, Pacific Northwest Research Station, USDA Forest Service, spowell@fs.fed.us Forest disturbance and recovery processes have important impacts on carbon dynamics, but are known to vary spatially by forest type and forest ownership, as well as temporally by economic and climatic condition. At a national scale, Landsat data are ideal for capture of these spatial and temporal variations because of their small grain size, their spectral properties, and their consistency over more than three decades. Landsat data therefore constitute the core of both phases of the NASA funded North American Forest Disturbance (NAFD) project, a component of the North American Carbon Program. Here, we present summary estimates of yearly forest disturbance rates for the 48 conterminous United States from 1985 to 2006. Estimates are derived from a sample of scenes chosen to represent a wide range of forest types and geographic areas across the country. Within each scene, the Vegetation Change Tracker (VCT) algorithms developed by Huang for this project were applied to biennial stacks of Landsat Thematic Mapper (TM) imagery to map disturbance in forests. Estimates for the eastern and western U.S. forests are considered separately. Year-to-year forest disturbance rates across the country were correlated with both economic and natural factors. Overall rates ranged from 1 to 2% per year, suggesting complete forest turnover times of 50 to 100 years. These forest disturbance estimates represent the first national-scale measurement of forest disturbance using consistent methods and resource-management-scale satellite imagery, complementing the field based estimates of disturbance from the Forest Inventory and Analysis (FIA) program.

Keywords: Diagnosis, Regional/Continental Synthesis 52: Interannual variability in the temperature-responsiveness of CO2 flux from forest and peatland soils

52: Interannual variability in the temperature-responsiveness of CO2 flux from forest and peatland soils Randy K Kolka, USDA Forest Service Northern Research Station, rkolka@fs.fed.us (Presenting) Peter Weishampel, Northland College, peter.weishampel@gmail.com Jennifer Y King, UC Santa Barbara, jyking@geog.ucsb.edu

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Northern forests and peatlands store large amounts of carbon in soils. The development of robust predictions of carbon fluxes from these ecosystems is important to improving biogeochemical models, especially in the context of global environmental change. We measured fluxes of CO2 from upland forest and peatland soils in the Marcell Experimental Forest (northern Minnesota, USA) from 2005 through 2007. We compared fluxes from upland and peatland hydrologic settings and also used regression approaches to examine the effectiveness of soil temperature, soil moisture, and water table level in predicting CO2 flux. Differences between upland and peatland CO2 flux were sometimes apparent but were not consistent across sampling years. In 2005, the mean upland CO2 flux was significantly higher than the mean peatland flux; in both 2006 and 2007, peatland fluxes exceeded upland fluxes, though the difference was not significant. Soil temperature was generally a stronger predictor of CO2 flux than was soil moisture or water table, but its predictive strength varied by hydrologic setting and year. In 2005, these variables explained roughly 60% of the variation of CO2 flux in both uplands and peatlands, but the strength of these predictive relationships declined in 2006 and 2007. Our study highlights the potential role of soil temperature in feedbacks between climate and the carbon cycle, but also illustrates a strong need for understanding interannual variability in the temperature responsiveness of CO2 flux. Keywords: Attribution, Site-level Synthesis 53: Dissolved organic matter production and stabilization across pedogenic thresholds

53: Dissolved organic matter production and stabilization across pedogenic thresholds Marc Gerald Kramer, UC Santa Cruz, mkramer@es.ucsc.edu (Presenting) Jonathan Sanderman, UC Santa Cruz, jsandman@es.ucsc.edu We examined the composition of dissolved organic matter (DOM) and its interaction with soil minerals across a substrate age gradient in Hawai'i. Across the 4.1 million year gradient, both forest type (Meterosideros polymorpha) and climate (2500 mm MAP) are well constrained, while soils ranging from base cation-rich primary minerals at the youngest site to metastable poorly-crystalline oxyhydroxides at intermediate aged sites to crystalline oxides at the oldest sites. Our objectives were to (1) determine the type and sources of organic matter that accumulates with depth, (2) assess interactions between soil minerals, metals and DOM, and (3) assess the possible mechanisms for DOM accumulation. As an initial step in this project we developed a soil column leaching experiment to examine DOM fluxes and chemistry, using field moist soil samples. Sequentially deeper soil samples were collected from 5 sites across a substrate age gradient (300y - 4.1My) of mantle-derived lava. Samples from major organic and mineral soil horizons (O, A, B) were the repacked into 4” PVC columns. A series of column leaching experiments were then performed by percolating rainwater through organic and subsequently mineral soil cores. In addition to measuring fluxes of DOM (both carbon and nitrogen) and CO2, we have measured major cations, anions, UV absorbance, δ13C and bioavailability of DOM. Preliminary results suggest large differences in DOM quantity and possibly quality being produced from the O horizons across the gradient. These differences correspond to know differences in nutrient availability and ecosystem productivity between sites. DOM interactions with the mineral soil varied considerably suggesting that pedogenic state plays a strong role in determining the fate of DOM in mineral soils, including the extent to which interaction, recalcitrance and accessibility influence DOM stabilization in soil.

Keywords: Attribution 54: Modeling impacts of physiological response and species composition on ecosystem respiration with carbon-13 measurements

54: Modeling impacts of physiological response and species composition on ecosystem respiration with carbon-13 measurements Chun-Ta Lai, San Diego State University, lai@sciences.sdsu.edu (Presenting) James Ehleringer, University of Utah, ehleringer@biology.utah.edu Stable carbon isotope ratio measurements provide additional constraints in the atmospheric inversion analysis. Here we present measurements of carbon-13 ratios of ecosystem respiration (d13CR) observed in 10 ecosystems, many of which are part of AmeriFlux. Systematic variations in d13CR have been reported with an average intra-seasonal variation of 2.3±0.5 ‰ in the Wind River Experimental Forest in southern Washington, USA during the period of 2001—2007. This seasonal pattern of d13CR was consistently observed in three coniferous forests of relatively uniform lifeform in the Pacific Northwest USA (Wind River Canopy Crane, Mary-Fir, and Metolius). In contrast, we observed no apparent seasonal differences in the d13CR value at Harvard Forest, a mixed deciduous forest, during the same period. Two possible mechanisms have been suggested to explain inter- and intra-annual variations in d13CR: 1) canopy physiological response (stomatal closure) to drought and 2) shifts in species composition within an ecosystem. The former is most tractable for the observed d13CR variation in stands with a uniform lifeform. The Harvard Forest is a mixed deciduous forest where shifts are occurring in the proportion of major species, Red Oak (ring-porous) and Red Maple (diffuse-porous). Shifts in species dominance within an ecosystem may result in d13CR values where species effects and environmental response effects offset each other. Alternatively, ring-porous species may exhibit much less dynamic d13CR patterns than diffuse-porous or tracheid-dominated forest species. We will use models to evaluate the relative impacts of physiological response and species composition on d13CR variation. Explicitly including these mechanisms may result in an improvement in modeling ecosystem respiration, a critical process if we were to successfully model atmospheric 13CO2 to aid the inversion analysis of atmospheric CO2.

Keywords: Attribution, Site-level Synthesis 55: Modeling CO2 emissions in Prairie Pothole region using DNDC model and remotely sensed data

55: Modeling CO2 emissions in Prairie Pothole region using DNDC model and remotely sensed data Zhengpeng Li, ASRC, contractor to USGS EROS, zli@usgs.gov (Presenting) Shuguang Liu, USGS EROS, sliu@usgs.gov Robert Gleason, USGS NPWRC, rgleason@usgs.gov Increasing greenhouse gas (GHG) concentrations and associated climate change have stimulated interest in the potential of croplands and restored wetlands and grasslands in the Prairie Pothole Region (PPR) to sequester atmospheric carbon. The USGS Northern Prairie Wildlife Research Center has collected GHG (CO2, N2O, CH4) emission data in the growing seasons 2005 and 2006 from diverse ecosystems (cropland, restored cropland, and native prairie) in the region. Based on these field observations and remotely sensed vegetation data (MODIS NPP/LAI), we simulated the CO2 emissions in these different ecosystems in central Minnesota. Our simulated results in seasonal CO2 emissions showed a good agreement with field observations, but the daily CO2 emission simulation didn’t catch some high daily CO2

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emissions that occurred in the field. In addition, the simulated results showed less spatial variance within the watershed and across the ecosystems. Our modeling indicates that the estimation and prediction of CO2 emission in the wetland catchments are impaired not only by the large spatial and temporal variability but also by the dynamic nonlinear relations between vegetation and soil interactive processes. The research also indicates that the quantification and modeling of GHG emissions in the Prairie Pothole region should include the uncertainty analysis across different ecosystems. Keywords: Attribution, Decision Support, Site-level Synthesis 56: Wall-to-Wall Forest Dynamics For NACP Modeling

56: Wall-to-Wall Forest Dynamics For NACP Modeling Jeffrey Masek, NASA GSFC, Jeffrey.G.Masek@nasa.gov (Presenting) Robert Wolfe, NASA GSFC, robert.e.wolfe@nasa.gov Samuel N. Goward, University of Maryland, sgoward@umd.edu Chengquan Huang, University of Maryland, cqhuang@umd.edu Gretchen Moisen, US Forest Service, gmoisen@fs.fed.us Warren B. Cohen, US Forest Service, warren.cohen@oregonstate.edu Feng Gao, ERT/GSFC, feng.gao-1@nasa.gov Forrest Hall, UMBC/GSFC, forrest.g.hall@nasa.gov Data on forest disturbance, regeneration, conversion, and age structure are useful for parameterizing biogeochemical models. We discuss three activities within NACP that are generating “wall-to-wall” assessments of forest dynamics from Landsat-type remote sensing data, as a complement to the North American Forest Dynamics (NAFD) sampling program implemented by S.N. Goward (University of Maryland): (1) The LEDAPS project at NASA GSFC has created a North American forest disturbance map for 1990-2000 from ~2200 Landsat frames, focusing on stand-clearing events (fire, clear-cut harvest). Results from this study indicate that nationally ~0.9 % +/-0.2 of US forest land is disturbed each year, with higher rates (2-3% per year) in the southeast, Pacific Northwest, and Maine. (2) As a follow-on to the LEDAPS activities, ASTER imagery is being combined with Landsat to produce continental forest disturbance record at five-year intervals for the period 1990-2005. (3) Through the NAFD project, the national sample Landsat frames are used to train a statistical model of forest disturbance for the 2000-2006 period. This approach merges several wall-to-wall “predictor” variables, including LEDAPS disturbance estimates, demographic/ownership information, and MODIS-based biomass and forest type maps in order to interpolate the NAFD results across the landscape (see also the related presentation by G. Moisen, USFS). We will discuss each of these mapping activities, including the space-time granularity of the results, and the types of disturbance detected by each approach. Keywords: Attribution 57: Monitoring of Landscape Freeze-Thaw in the Terrestrial High Latitudes with Satellite Microwave Remote Sensing: Relationships with Growing Season and Land-Atmosphere CO2 Exchange

57: Monitoring of Landscape Freeze-Thaw in the Terrestrial High Latitudes with Satellite Microwave Remote Sensing: Relationships with Growing Season and Land-Atmosphere CO2 Exchange Kyle C McDonald, Jet Propulsion Lab, California Institute of Technology, kyle.mcdonald@jpl.nasa.gov (Presenting) John S Kimball, Flathead Lake Biological Station, The University of Montana;, Numerical Terradynamic Simulation Group, The University of Montana, , , , ,, johnk@ntsg.umt.edu Ke Zhang, Numerical Terradynamic Simulation Group, The University of Montana, ke.zhang@grizmail.umt.edu Youngwook Kim, Numerical Terradynamic Simulation Group, The University of Montana, youngwook.kim@ntsg.umt.edu David Ganem, Jet Propulsion Lab, California Institute of Technology, david.ganem@jpl.nasa.gov Erika Podest, Jet Propulsion Lab, California Institute of Technology, erika.podest@jpl.nasa.gov Approximately 68-80 percent of the North American region experiences seasonal freezing and thawing with the relative influence of these processes on terrestrial carbon budgets generally increasing at higher latitudes and elevations. The timing and duration of surface and soil freeze-thaw state is closely linked to vegetation phenology and growing season dynamics in northern temperate, sub-alpine, boreal and arctic biomes. Variability in these environmental variables also has been shown to have dramatic impacts on spatial patterns, seasonal to interannual variability and long-term trends in terrestrial carbon budgets and surface-atmosphere trace gas exchange, primarily through biophysical controls on both photosynthesis and ecosystem respiration. These processes are strongly influenced by land cover and soil properties, as well as the timing and condition of seasonal snow cover. We utilize time series satellite-borne microwave remote sensing to examine spatial and temporal variability in seasonal freeze/thaw cycles for North America and circumboreal land areas. Regional measurements of freeze-thaw timing are derived using daily brightness temperature measurements from the Special Sensor Microwave Imager (SSM/I) and the SeaWinds-on-QuikSCAT scatterometer. Spatial patterns and interannual variability in the timing of spring thaw are examined in relation to regional biosphere activity indicated by atmospheric CO2 measurements and annual net primary production (NPP) derived from AVHRR Pathfinder and MODIS satellite data. Satellite observations of the timing of spring thaw correspond to seasonal patterns and interannual variability in the timing of CO2 uptake and associated vegetation activity indicated by atmospheric CO2 measurements and spatial patterns of NPP. Satellite observations of seasonal thaw provide a consistent, indirect measure of regional biospheric activity at boreal latitudes. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, and at The University of Montana, Missoula, under contract to the National Aeronautics and Space Administration. Keywords: Attribution, Regional/Continental Synthesis 58: Using radiocarbon measurements to evaluate fossil fuel emission inventories.

58: Using radiocarbon measurements to evaluate fossil fuel emission inventories. John B Miller, NOAA/ESRL, john.b.miller@noaa.gov (Presenting) Scott J Lehman, University of Colorado/INSTAAR, scott.lehman@colorado.edu Colm Sweeney, NOAA/ESRL, colm.sweeney@noaa.gov Pieter P Tans, NOAA/ESRL, pieter.tans@noaa.gov

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Fossil fuel emissions remain the single largest component of the annual North American carbon budget. Despite the fact that these fluxes are relatively well known, with uncertainties of about 10%, small errors in the total or in the spatial and seasonal distributions can result in substantial errors in inferred biospheric fluxes. Here, we will use measurements of radiocarbon in both atmospheric CO2 and in annual plants to evaluate fossil fuel inventories. Fossil fuel is devoid of radiocarbon making the radiocarbon content of the atmosphere and that in annual plants ideal tracers for fossil fuel emissions. We will use the atmospheric transport model TM5 to transport two emission maps: the high-resolution VULCAN product (www.purdue.edu/eas/carbon/vulcan) and the fossil fuel map used in the CarbonTracker data assimilation system, which is based on CDIAC/BP country totals with internal distribution based on population. Model tests show that the atmospheric 14CO2 distribution over the United States is controlled largely by fossil fuel emissions, although we will specify the full atmospheric budget of 14CO2 in TM5. Thus, we will compare 14CO2 simulated with TM5 with time series of atmospheric 14CO2 measurements at 4 vertical profile sites (BNE, LEF, CMA, NHA) and one surface site (NWR). Additionally, we will compare the near surface simulated 14CO2 from both flux maps with observations of radiocarbon in annual plants (Hsueh et al, 2007). Keywords: Diagnosis, Attribution 59: Estimating Photochemical Contributions to Coastal Carbon Cycles from Remote Sensing

59: Estimating Photochemical Contributions to Coastal Carbon Cycles from Remote Sensing William L. Miller, University of Georgia, bmiller@uga.edu (Presenting) Heather Reader, University of Georgia, hereader@uga.edu Cedric G. Fichot, University of South Carolina, fichot@mailbox.sc.edu Most photochemistry in the ocean is driven by colored dissolved organic matter (CDOM). When considering marine carbon cycles, the most important photochemical reactions involving CDOM are CO2 & CO production as well as induced changes in biologically labile organic carbon. The large-scale significance of this photochemistry can be modeled by combining UV radiation and attenuation models based on remotely sensed ocean color with spectral photochemical reaction efficiencies (i.e. apparent quantum yields: AQY) appropriate for each reaction and every oceanic setting. To assign suitable AQY spectra for a subtropical coastal environment, water samples were taken in the vicinity of Sapelo Island, GA, USA, filtered, and irradiated for AQY determinations. CO2 and CO production in sealed quartz cells was measured as TIC with a Shimadzu TOC-V CPN analyzer and with a reduced gas analyzer respectively. Photoconversion of refractory organic carbon to biologically labile products (BLPs) was determined using O2 consumption in post-irradiation, dark incubations by a cultured marine bacterium, Silicibacter pomeroyi. AQY spectra were input into the SeaUV/SeaUVc algorithms (Fichot et al., 2008) for coastal remote sensing scenes and UV climatologies to create photochemical reaction maps in the South Atlantic Bight. Total contributions to the coastal carbon cycles are evaluated in light of measured statistical variation for AQYs. Results have significance for both the carbon cycle and microbial ecology in coastal marine systems. Keywords: Attribution 60: Using a Sample of Temporally Dense Landsat-based Disturbance Maps to Explore and Map Rates of Forest Disturbance across the Conterminous U.S. from 2000 to 2006

60: Using a Sample of Temporally Dense Landsat-based Disturbance Maps to Explore and Map Rates of Forest Disturbance across the Conterminous U.S. from 2000 to 2006 Gretchen G. Moisen, US Forest Service, Rocky Mountain Research Station, gmoisen@fs.fed.us (Presenting) Jock A. Blackard, US Forest Service, Rocky Mountain Research Station, jablackard@fs.fed.us Sean P. Healey, US Forest Service, Rocky Mountain Research Station, seanhealey@fs.fed.us Samuel N. Goward, University of Maryland, sgoward@umd.edu Warren B. Cohen, US Forest Service, Pacific Northwest Research Station, warren.cohen@oregonstate.edu Jeffrey G. Masek, NASA Goddard Space Flight Center, Jeffrey.G.Masek@nasa.gov G. James Collatz, NASA Goddard Space Flight Center, jim.collatz@nasa.gov Michael A. Wulder, Canadian Forest Service, mwulder@nrcan-rncan.gc.ca Chengquan Huang, University of Maryland, cqhuang@umd.edu Robert Kennedy, Oregon State University, robert.kennedy@oregonstate.edu Scott Powell, Oregon State University, Scott.Powell@oregonstate.edu Nancy Thomas, University of Maryland, nthomas1@umd.edu Karen Schleeweis, University of Maryland, ska1@umd.edu Adrienne Hinds, University of Maryland, ahinds2@umd.edu Khaldoun Rishmawi, University of Maryland, rishmawi@umd.edu The lack of comprehensive and spatially-explicit historical vegetation data over the U.S. challenges the ability of scientists and land managers to understand cumulative effects of natural and anthropogenic disturbances across the landscape. The North American Forest Dynamics (NAFD) project, involving the integration of forest inventory and satellite data to characterize the effects of forest disturbance across North America, has begun to address this problem. Using Landsat imagery going back to 1972 in 2-year intervals, the project has produced forest disturbance maps with associated changes in tree biomass for 23 sample scenes across the country. Here, we extend this detailed information available on the sample scenes to more general nationwide maps of forest dynamics over the U.S. for the years 2000 to 2006. We first explore the relationship between forest disturbance rates (observed on NAFD products) and nationally available surrogates for potential drivers of this disturbance. Analyses are conducted at several spatial scales ranging from 0.5 to 50 km, and at 2 and 6 year time intervals. The potential drivers of disturbance include: 1) past disturbance derived through the Landsat Ecosystem Disturbance and Adaptive Processing System (LEDAPS), which characterizes stand-replacing forest disturbance from 1990 to 2000; 2) current forest type and abundance as represented by MODIS-based aboveground live tree biomass, forest probability and forest type maps; 3) ownership; and 4) demographic information. In addition, biennial extractions from the MODIS reflectance product MCD43A4 are also investigated as a surrogate for current disturbance to enhance the models’ predictive performance. The strongest of these models are then used to map forest disturbance rates over the conterminous US for the 2000-2006 timeframe. Keywords: Attribution, Prediction, Regional/Continental Synthesis

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61: Carbon Stocks and Fluxes in Temperate Forest Ecosystems of Nuevo Leon, Mexico

61: Carbon Stocks and Fluxes in Temperate Forest Ecosystems of Nuevo Leon, Mexico Jose de Jesus Navar, CIIDIR-IPN Unidad Durango, jnavar@ipn.mx (Presenting) In this research report, I present information on carbon stocks and fluxes in aboveground biomass of temperate forests of the Sate of Nuevo Leon, Mexico. This information was derived from 63 sites inventoried within the framework of the forest inventory of 2004-2006. It can be concluded that temperate forests are in juvenile state with diameter distributions skewed to the right, with low tree density, low densities of standing volume, biomass and carbon stocks. Mean (confidence interval) carbon stocks are 37.08 Mg ha-1 (± 5.94 Mg ha-1), indicating that temperate forests have a total carbon stock of 11, 239 479 Mg C (± 1,802 319 Mg C). Mean carbon influxes have a mean (confidence interval) of 0.36 Mg ha-1 y-1 (0.04 Mg ha-1 y-1). Temperate forests of the State of Nuevo Leon sequester a total carbon amount of 190 955 Mg y-1 (± 21 217 Mg y-1). Therefore, there is a great potential to sustainable manage these forests for a wide range of goods and services. To sustainable manage these forests, It is recommended to harvest trees at a light rate for 15 years and to carry out the appropriate silvicultural practices to enhance tree diversity as well as structural diversity to increase carbon sequestration. Key words: Aboveground biomass productivity, carbon sequestration. Keywords: Attribution 62: Near-surface remote sensing of spatial and temporal variation in canopy phenology

62: Near-surface remote sensing of spatial and temporal variation in canopy phenology Andrew D Richardson, University of New Hampshire, andrewr@solo.sr.unh.edu (Presenting) Bobby H Braswell, University of New Hampshire, rob.braswell@unh.edu David Y Hollinger, USDA Forest Service, davidh@hypatia.unh.edu Julian P Jenkins, University of New Hampshire, julian.jenkins@unh.edu Scott V Olliner, University of New Hampshire, scott.ollinger@unh.edu There is a need to document how plant phenology is responding to global change factors, particularly warming trends. Near-surface remote sensing, using radiometric instruments or imaging sensors, has great potential to improve phenological monitoring because automated observations can be made at high temporal frequency. Here we build on previous work and show how inexpensive, networked digital cameras (“webcams”) can be used to document spatial and temporal variation in the spring and autumn phenology of forest canopies. We use two years of imagery from a deciduous, northern hardwood site, and one year of imagery from a coniferous, boreal transition site. A quantitative signal is obtained by splitting images into separate red, green and blue color channels, and calculating the relative brightness of each channel for “regions of interest” within each image. We put the observed phenological signal in context by relating it to seasonal patterns of gross primary productivity, inferred from eddy covariance measurements of surface-atmosphere CO2 exchange. We show that spring increases, and autumn decreases, in canopy greenness can be detected in both deciduous and coniferous stands. In deciduous stands, an autumn red peak is also observed. The timing and rate of spring development and autumn senescence varies across the canopy, with greater variability in autumn than spring. Interannual variation in phenology can be detected both visually and quantitatively; delayed spring onset in 2007 compared to 2006 is related to a prolonged cold spell from day 85 to day 110. We have expanded this monitoring effort to include 9 AmeriFlux and Fluxnet-Canada sites and will work towards developing improved understanding of relationships between phenology and ecosystem function, particularly as related to exchanges of carbon and water. Keywords: Attribution 63: Landscape Structure Controls Soil CO2 Efflux Variability in Complex Terrain: Scaling From Point Observations to Watershed Scale Fluxes

63: Landscape Structure Controls Soil CO2 Efflux Variability in Complex Terrain: Scaling From Point Observations to Watershed Scale Fluxes Diego A. Riveros-Iregui, Montana State University & University of Colorado - Boulder, riveros@colorado.edu (Presenting) Brian L. McGlynn, Montana State University, bmcglynn@montana.edu (Presenting) Howard E. Epstein, University of Virginia, hee2b@virginia.edu Daniel Welsch, Canaan Valley Inst., danny.welsch@canaanvi.org Ryan Emanuel, Appalachian State Univ., emanuelre@appstate.edu Daniel Muth, University of Virginia, djm7f@virginia.edu Understanding the spatial variability of soil CO2 efflux depends upon knowledge of the physical and biogeochemical processes leading to soil CO2 production and transport. Particularly in complex terrain, the interactions among spatially variable soil temperature, soil water content, vegetation, substrate, and soil physical properties induce large heterogeneity in the magnitude of soil CO2 efflux. We investigated the spatial and temporal variability of soil CO2 efflux measured at 62 sites of a moderately complex watershed of the northern Rocky Mountains. The sites were distributed across a 393-ha watershed and were characteristic of the spatial heterogeneity of the landscape (e.g., slope, aspect, upslope accumulated areas [UAA]). Growing season (83-day) cumulative soil CO2 efflux varied from ~300 g CO2 m2 to ~2000 g CO2 m2, depending upon landscape position, with a median of 879.8 g CO2 m2. Highest rates of soil CO2 efflux were observed in areas with persistent high soil water content (riparian meadows), whereas lower rates of soil CO2 efflux were observed on forested uplands (98% of the watershed). Furthermore, we found that UAA, a surrogate measure of the lateral redistribution of soil water, was positively correlated with seasonal soil CO2 efflux at all upland sites (r2 = 0.51), increasing in explanatory power when sites were separated by the two major aspects of the watershed (SE aspects r2 = 0.65; NW aspects r2 = 0.61). Using the empirically developed UAA-soil CO2 efflux relationship, we up-scaled measured soil CO2 efflux to the entire watershed and found watershed-scale soil CO2 efflux of 799.45 ± 151.1 g CO2 m-2 over 83 days. These estimates compared well (within 2%) with independent eddy-covariance estimates of nighttime ecosystem respiration measured over the forest canopy for the same period (absolute error of 11.7 g CO2 m-2 over 83 days). Our study represents an empirical quantification of seasonal watershed-scale soil CO2 efflux and demonstrates that UAA (i.e., catchment area) is an important control on large-scale (~km2) variability of soil CO2 efflux particularly in semi-arid, subalpine ecosystems. Keywords: Attribution, Site-level Synthesis

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64: Snow, Soil Freeze/Thaw Dynamics, and the Carbon Cycle

64: Snow, Soil Freeze/Thaw Dynamics, and the Carbon Cycle Kevin Schaefer, National Snow and Ice Data Center, kevin.schaefer@nsidc.org (Presenting) Tingjun Zhang, National Snow and Ice Data Center, tzhang@nsidc.org Lixin Lu, Cooperative Institute for Research in Environmental Sciences, lixin@atmos.colostate.edu We analyzed output from the Simple Biosphere Carnegie-Ames-Stanford Approach (SiBCASA) model to evaluate how snow cover, soil temperature, and soil freeze-thaw processes influence terrestrial net carbon flux. We ran SiBCASA globally with the NCEP reanalysis at 2x2 degrees and locally at eddy covariance flux towers with the NARR reanalysis. Net Ecosystem Exchange (NEE) is R - GPP, where R is respiration and GPP is Gross Primary Productivity or photosynthesis. GPP for plant growth removes CO2 from the atmosphere while R due to the decay of dead plants returns CO2 to the atmosphere. Variations in winter snow depth are preserved as variations in soil temperature, producing time-delayed effects on R and GPP and modulating NEE for the entire year. Deeper snow in winter insulates the soil, resulting in warmer soil temperatures the following spring and summer, increasing R and GPP, but at different magnitudes throughout the year. In spring and fall, warmer soils increase R, but GPP is low, resulting in increased NEE. The magnitude of the effect of winter snow depth on summer NEE depends on what limits GPP. In permafrost, active layer depth limits GPP, so warmer winter soil temperatures increase active layer depth in summer, increasing GPP and decreasing NEE. In boreal forests, summer GPP is limited by water availability, so winter snow depth influences spring and fall NEE by modulating R, but exerts a weaker influence on summer NEE. Keywords: Diagnosis, Attribution, Site-level Synthesis, Regional/Continental Synthesis 65: Spatial and Temporal Variability of Frozen Ground and Snow Cover in the Northern Hemisphere

65: Spatial and Temporal Variability of Frozen Ground and Snow Cover in the Northern Hemisphere Tingjun Zhang, National Snow and Ice Data Center, University of Colorado, tzhang@nsidc.org (Presenting) James McCreight, National Snow and Ice Data Center, University of Colorado, mccreigh@nsidc.org Kevin Schaefer, National Snow and Ice Data Center, University of Colorado, kevin.schaefer@nsidc.org (Presenting) Changes in soil thermal regime and soil freeze/thaw cycle have significant impact on carbon exchange between the atmosphere and the land surface. Snow cover plays a critical role on soil thermal regime and soil freeze/thaw status in cold seasons/cold regions, thus has dramatically impact on ecosystem and carbon cycle as a whole. The ultimate goal of this study is to investigate spatial and temporal variability of seasonally frozen ground and snow cover in the Northern hemisphere and then to further study how changes in frozen ground and snow conditions influence ecosystem and carbon exchange. To archive this goal, we collected all available frozen ground and snow data from various sources and develop a comprehensive frozen ground and snow depth data time series over Northern Hemisphere. We have obtained in-situ snow depth and snow water equivalent (SWE) data from more than 6000 stations. We also obtained soil temperatures at various depths and soil freeze/thaw depth data from more than 2000 stations. Daily snow depth/SWE derived from passive microwave satellite remote sensing data from 1978 through 2005 were obtained from the National Snow and Ice Data Center, University of Colorado at Boulder. Using NSIDC frozen soil algorithm, daily area extent of near-surface soil freeze-thaw status was derived over the period from 1978-2005 using passive microwave satellite remote sensing data. Based on in-situ data at stations where both snow depth/SWE are available, we have obtained monthly snow density climatology and its standard deviation for five different snow types over North America. We further grided monthly snow density across NA with resolution of 25 km. Finally, we use daily snow depth/SWE from SMMR and SSM/I data as background and in-situ daily snow depth/SWE as control to generate a combined daily snow depth/SWE data product. We will conduct detailed analysis on their spatial and temporal variability in the past few decades over NH. We will present all details of frozen ground and snow products and discuss their potential applications for ecosystem and carbon exchange studies. Keywords: Attribution 66: Interannual variation of carbon fluxes from a tropical, a temperate, and a boreal evergreen forest: the role of forest dynamics and climate

66: Interannual variation of carbon fluxes from a tropical, a temperate, and a boreal evergreen forest: the role of forest dynamics and climate Carlos A Sierra, Oregon State University, carlos.sierra@oregonstate.edu (Presenting) Mark E Harmon, Oregon State University, Mark.Harmon@oregonstate.edu Interannual variation of carbon fluxes can be attributed to different biotic and abiotic controls that operate at different spatial and temporal scales. The type and frequency of disturbance, forest dynamics, and climate regimes are important sources of variability. Assessing the variability of carbon fluxes from these specific sources can enhance the interpretation of past and current observations. Being able to separate the variability caused by stand dynamics from that induced by climate will also give us the ability to determine if the current observed carbon fluxes are within an expected range or by contrast, other non-tested factors affect the annual variation in the overall carbon flux. Sources of interannual variation in ecosystem carbon fluxes were explored using the simulation model STANDCARB from three evergreen forest ecosystems, a tropical forest, a temperate coniferous forest, and a boreal forest. We identified key processes that introduced variation in annual carbon fluxes, but their relative importance differed among the ecosystems studied. In the tropical site, forest dynamics contributed ~30% of the total variation among annual carbon fluxes. In the temperate and boreal sites, where many forest processes occur over longer temporal scales than those at the tropical site, climate controlled more of the variation among annual carbon fluxes. These results suggest that climate-related variability affects the internal rates of carbon exchange differently among sites. Simulations in which climate varied from year-to-year (based on historical records of climate variation) had less net carbon storage than simulation in which climate was held constant (based on historical records of monthly average climate); a result caused by the shape of the relationship between temperature and respiration. This suggests that under a more variable temperature regime larger respiratory fluxes become more frequent and enough to cause reduction in carbon stores. Keywords: Site-level Synthesis 67: Identification of greenhouse gas source signatures in the San Francisco Bay area using in situ aircraft measurements

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67: Identification of greenhouse gas source signatures in the San Francisco Bay area using in situ aircraft measurements Anna Karion, University of Colorado and NOAA/ESRL, anna.karion@noaa.gov Marc Fischer, Lawrence Berkeley Laboratory, mlfischer@lbl.gov Doug Day, Scripps/UCSD, daday@ucsd.edu Colm Sweeney, University of Colorado and NOAA/ESRL, colm.sweeney@noaa.gov (Presenting) Tom Sherwood, KalScott Engineering, tom.sherwood@kalscott.com Nenad Zagorac, UC Davis, nezagorac@ucdavis.edu Suman Saripalli, KalScott Engineering, suman.saripalli@kalscott.com Ian Faloona, UC Davis, icfaloona@ucdavis.edu Stephen Montzka, NOAA/ESRL, stephen.a.montzka@noaa.gov Ben Miller, University of Colorado and NOAA/ESRL, ben.r.miller@noaa.gov Lloyd Miller, STC and NOAA/ESRL, lloyd.miller@noaa.gov Chuanfeng Zhao, Lawrence Berkeley Laboratory, czhao@lbl.gov Janusz Eluszkiewicz, Atmospheric and Environmental Research, Inc, jel@aer.com Thomas Nehrkorn, Atmospheric and Environmental Research, Inc, nehrkorn@aer.com Quantification of specific sources and sinks of greenhouse gases is necessary for validation of emission flux estimates and supports recent efforts to regulate greenhouse gas emissions. In situ atmospheric measurements provide a valuable contribution to the effort of quantifying sources and sinks. In this study, continuous in situ measurements of carbon dioxide, methane, and carbon monoxide were made from a light aircraft in the San Francisco Bay area between June 17 and June 24, 2008. In addition to the continuous measurements, twelve flask samples were taken on each flight using NOAA/ESRL Programmable Flask Packages. These samples provided measurements of a variety additional atmospheric trace gases, including N2O, H2, benzene, HCFCs, and additional halocarbons. Atmospheric transport and footprints for the flight tracks have been computed using the Stochastic Time-Inverted Lagrangian Transport (STILT) model driven by customized output from the Weather Research and Forecasting (WRF) model, allowing for an analysis of the origin of the various air masses observed. Large signals were observed during the campaign: urban air plumes with highly correlated CO2, CH4 and CO, as well as agricultural signatures with enhanced CH4 coincident with depleted CO2. The last two days of flights, on June 23-24, captured a large signal from the northern California wildfires as well, enabling the comparison of the signatures from the fires to those of other sources. Keywords: Attribution 68: Temperature responses of soil carbon dynamics and its implication for regional carbon balance in Yukon River Basin, Alaska

68: Temperature responses of soil carbon dynamics and its implication for regional carbon balance in Yukon River Basin, Alaska Bo Tao, Mendenhall Postdoctoral Fellow, U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, Sioux Falls, SD 57198, USA, taobo.eco@gmail.com (Presenting) Shuguang Liu, U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, Sioux Falls, SD 57198, USA, sliu@usgs.gov Zhengxi Tan, ARTS, Contractor to USGS EROS Center, Sioux Falls, SD 57198, USA, Work performed under USGS contract 08HQCN0007, ztan@usgs.gov The acceleration of Soil Organic Matter (SOM) decomposition with climate warming is a major concern in regional and global carbon budgets. Due to variability in soil profile composition (e.g., moss, organic layer, mineral layer, and permafrost) and various disturbances (e.g., land fire) in boreal areas, the response of soil carbon dynamics to warming may vary greatly within different soil layers and across landscape. Most model parameterizations for soil carbon decomposition rely heavily on our understanding from non-boreal regions through the use of constant Q10 coefficient, and do not have robust hydro-thermal algorithms to simulate the compounding effects of soil water fluctuation, permafrost degradation, and temperature change on soil carbon dynamics and ecosystem change. In this study, we adapted a physically-based multi-layer soil hydro-thermal module from the Integrated BIosphere Simulator (IBIS) and coupled it with the Erosion-Deposition-Carbon Model (EDCM) to investigate the evolution of soil profile under the impacts of disturbances and succession, and the role of soil carbon in deep layers in ecosystem carbon balance at two boreal forest eddy covariance flux tower sites in the Alaskan Yukon River Basin. Compared to a simple bulk modeling method (one single layer), our results showed more soil carbon release and exemplified seasonal fluctuations in deep layers at both sites. The deeper soil layers exhibited more sensitivity to increasing temperatures than do upper layers, and improved soil moisture and drainage conditions due to active layer thickening accelerated soil carbon release. These results suggest that more attention should be paid to improve simulations of the responses of soil moisture and temperature profiles to global climate change and disturbances at the site to regional scales to reduce uncertainties in the estimation of carbon fluxes and stocks in the Arctic region.

Keywords: Attribution, Site-level Synthesis 69: Seeing the trees for the forest: Nitrogen deposition alters tree carbon gain and survival across the northeastern U.S., responses vary by species.

69: Seeing the trees for the forest: Nitrogen deposition alters tree carbon gain and survival across the northeastern U.S., responses vary by species. R. Quinn Thomas, Cornell University, rqt2@cornell.edu (Presenting) Charles D. Canham, Cary Institute of Ecosystem Studies, canhamc@ecostudies.org Kathleen C. Weathers, Cary Institute of Ecosystem Studies, weathersk@ecostudies.org Christine L. Goodale, Cornell University, clg33@cornell.edu Assessments of regional forest carbon (C) balance have long speculated a role for atmospheric nitrogen (N) deposition. To date, however, evidence for an N effect has been restricted to plot-level fertilization and 15N experiments, biogeochemical modeling studies, and recent and controversial correlations between nitrogen deposition and C balance across 20 intensive C monitoring sites. These studies have yielded widely varying conclusions on the magnitude and even the direction of response (positive or negative effects on C storage). We assessed the effects of N deposition on forest growth and survival using forest inventory data from > 160,000 trees, spanning a 19-state region of the northeastern United States, and estimates of total (wet and plot-specific dry) inorganic N inputs (N deposition to the plots ranged from 3.2 to 11 kg N ha-1 y-1). The growth rates of 14 of the 24 region’s 24 most common tree species responded to N deposition. Nine species showed a monotonic increase in aboveground growth rates across the range of N deposition and some of these species experienced a doubling of

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growth rates. Four species showed humped-shaped responses. A single species, Pinus resinosa (red pine), showed a monotonic decline in growth across the range of deposition. Species responsiveness to N deposition increased with mean growth rate of the species. In the analysis of survival, 13 of the 24 species responded to N: eight species showed a monotonic decrease, 3 showed a monotonic increase and 1 showed a humped-shape response in survival. The stand-level analysis showed a distinctly humped-shaped relationship between N deposition and aboveground C increment, peaking at 6 kg N ha-1 yr-1, which can likely be explained by the distribution of species and their individual growth and mortality responses. Overall, our data suggest that moderate levels of N deposition have enhanced aboveground C accumulation in temperate forests of the northeastern U.S., but the shape and trajectory of the response is species-specific. Keywords: Attribution, Regional/Continental Synthesis 70: Attributing and predicting changes in regional carbon budget in Southeastern US during 1900-2050 through data-model integration

70: Attributing and predicting changes in regional carbon budget in Southeastern US during 1900-2050 through data-model integration Hanqin Tian, Auburn University, tianhan@auburn.edu (Presenting) Chi Zhang, Auburn University, zhangch@auburn.edu Guangsheng Chen, Auburn University, chenguq@auburn.edu Mingliang Liu, Auburn University, liuming@auburn.edu Wei Ren, Auburn University, renwei1@auburn.edu Xiaofeng Xu, Auburn University, xuxiaof@auburn.edu Chaoqun Lu, Auburn University, czl0003@auburn.edu Art Chappelka, Auburn University, chappah@auburn.edu Ge Sun, USDA Forest Service, ge_sun@ncsu.edu Shufen Pan, Auburn University, panshuf@auburn.edu Bray Bray Beltran Villarreal, Auburn University, bjb0008@auburn.edu Xia Song, Auburn University, xzs0002@auburn.edu Terrestrial ecosystems in the southeastern United States have experienced a complex set of multiple changes in climate, atmospheric composition, land use and natural disturbances in the 20th century. These multiple changes in the 21st century are expected to continue, which may alter the structure and functioning of terrestrial ecosystems and hence affect the regional carbon budget in the southeast. Using the Dynamic Land Ecosystem Model (DLEM) forced by multiple environmental factors, at first, we have examined how carbon fluxes and storage in southeastern United States have changed during 1900-2005 as a result of multiple stresses/changes and interactions among those stresses including land-cover/land use change, climate variability, atmospheric composition (carbon dioxide and tropospheric ozone), precipitation chemistry (nitrogen composition), and natural disturbances. Then we use the same model in conjunction with the scenarios of future climate, atmospheric composition and land use, further to investigate potential impacts of these multiple changes on carbon sources and sinks across the southeast in the first half of 21st century. Our analysis suggests that the net carbon exchange of terrestrial ecosystems with the atmosphere in this region show substantially interannual and spatial variations in the past. Forest recovery after cropland abandonment and natural disturbances have resulted in a carbon uptake, but rapid urbanization and rising tropospheric ozone pollution have led to a significant reduction in carbon storage in the southeast. Land-use change appears to be an important control over regional carbon dynamics in this area in the 20th century. The future patterns of regional carbon budget in the southeast will be controlled by changes in climate, atmospheric composition and land use and their interactions. Keywords: Diagnosis, Attribution, Prediction, Site-level Synthesis, Regional/Continental Synthesis, non-CO2 Greenhouse Gases Synthesis, Coastal Synthesis 71: Regional-Scale Airborne Observations of 14CO2 over North America and Adjacent Oceans

71: Regional-Scale Airborne Observations of 14CO2 over North America and Adjacent Oceans Stephanie A. Vay, NASA Langley Research Center, stephanie.a.vay@nasa.gov (Presenting) Stanley C. Tyler, University of CA - Irvine, styler@uci.edu Donald R. Blake, University of CA - Irvine, drblake@uci.edu Yonghoon Choi, National Institute of Aerospace, yonghoon.choi-1@nasa.gov Nicola J. Blake, University of CA - Irvine, nblake@uci.edu Glen W. Sachse, National Institute of Aerospace, glen.w.sachse@nasa.gov Glenn S. Diskin, NASA Langley Research Center, glenn.s.diskin@nasa.gov We present results of measurements of the 14C content in atmospheric CO2 during the 2006 MILAGRO/INTEX-B, and 2008 ARCTAS campaigns. Our findings for whole air samples collected onboard the NASA DC-8 during the April - May 2006 Pacific portion of the INTEX-B campaign indicated that the Asian outflow ambient 14C content in CO2 was ca. 62±6‰ (n=22). This is in good agreement with recent Northern Hemispheric studies of background CO2 in European and Alaskan air during the same time period. In contrast, ambient 14C content in CO2 over Mexico City and the surrounding region during the March 2006 MILAGRO mission had a surprisingly high average value of delta 14C = 72±26‰ (n=21). Furthermore, the majority of samples over Mexico were significantly higher than background for 14C while also higher in background CO2 mixing ratio. That result was quite unexpected as elevated CO2 concentration, particularly in urban regions, is normally associated with fossil fuel sources and would necessarily lead to depleted rather than elevated 14C content. One likely explanation, supported by a two-component isotope mixing curve of fossil fuel and biomass burning sources, is that CO2 from biomass burning, where the fuel source is stored biocarbon with age sufficient to have a higher 14CO2 value than current background air, contributes to elevated CO2 mixing ratios and a somewhat higher than average background 14C content. Biomass burning plumes were observed and tracked in the Mexico City region during MILAGRO. Other explanations requiring further investigation include the possibility of a 14C source from cement plants licensed for waste incineration within Mexico, 14CO2 transported from the Laguna Verde nuclear reactor facility in Vera Cruz, Mexico, or as yet unidentified 14CO2 sources. Analysis of the radiocarbon samples collected during the ARCTAS mission is underway and the results will be compared to those from earlier campaigns. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 72: Climate and Disturbance Effects on Forest Productivity in Oyster River and Chibougamau Study Areas

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72: Climate and Disturbance Effects on Forest Productivity in Oyster River and Chibougamau Study Areas Ziyu Wang, University of Alberta, ziyu.wang@ales.ualberta.ca (Presenting) Robert F. Grant, University of Alberta, robert.grant@ales.ualberta.ca Altaf Arain, McMaster University, arainm@mcmaster.ca Pierre Bernier, Canadian Forest Service, Laurentian Forestry Centre, pbernier@rncan.gc.ca Bin Chen, McMaster University, chenb9@univmail.cis.mcmaster.ca Jing Chen, University of Toronto, chenj@geog.utoronto.ca Nicholas Coops, University of British Columbia, nicholas.coops@ubc.ca Ajit Govind, University of Toronto, Ajit.govind@utoronto.ca Luc Guindon, Canadian Forest Service, Laurentian Forestry Centre, lguindon@cfl.forestry.ca Robbie Hember, University of British Columbia, robbie@hember.name Werner Kurz, Canadian Forest Service, Pacific Forestry Centre, Wkurz@pfc.cfs.nrcan.gc.ca Changhui Peng, University of Quebec at Montreal, peng.changhui@uqam.ca David Price, Canadian Forest Service, Northern Forestry Centre, dprice@nrcan.gc.ca Graham Stinson, Canadian Forest Service, Pacific Forestry Centre, gstinson@pfc.cfs.nrcan.gc.ca Jianfeng Sun, University of Quebec at Montreal, jianfeng_sun@yahoo.ca Tony Trofymow, Canadian Forest Service, Pacific Forestry Centre, ttrofymow@pfc.cfs.nrcan.gc.ca Jagadeesh Yeluripati, McMaster University, yjbabu@gmail.com The objective was to conduct landscape-level simulations of forest carbon dynamics for Oyster River and Chibougamau areas for several decades from the past to the present using historic inventory, disturbance and climate data for the purpose of applying and testing process-based vs. inventory-based modelling approaches. Models CBM-CFS3, Ecosys, C-CLASS, Can-IBIS and 3PG were used for Oyster River and models CBM-CFS3, Ecosys, C-CLASS, CAN-IBIS, TRIPLEX and INTEC were used for Chibougamau. The daily weather data constructed from meteorological records during 1920 – 1997 for Oyster River and 1928-2003 for Chibougamau, and then from 1998 to 2005 for Oyster River and 2004 to 2005 for Chibougamau under half-hourly weather data recorded at flux towers. The GIS data layers of soil, vegetation, harvesting, fire and fertilization were converted to 100m × 100m grid cells. For the Oyster River area, the model results showed that the annual average above-ground biomass(AGB) of the 2500 grid cells decreased sharply, losing 20,000~23,000 gCm-2 during 1928 to 1943 due to harvesting and slash burn in 1928, 1929, 1932, 1936, 1937, 1940, 1944, a fire in 1942 and harvesting with fires in 1938 and 1942. A gradual recovery of ecosystem carbon stocks followed this high disturbance period. The decline in above ground biomass from 1997 to 2005 resulted from the onset of a second harvesting. For Chibougamau area, the annual average AGB of all 6275 grid cells decreased sharply, losing 400~600 gCm-2 in 1963 since 666 grid cells were clearcut, 36 grid cells lost to infrastructure and 92 grid cells were partially cut. A gradual recovery of ecosystem carbon stocks followed this intense harvesting. The interannual variability in net biome productivity(NBP) from the process models was caused by interannual variability in weather. The disturbances of harvesting (clearcut and partial cut) and fire (slash burn and human caused burn) negatively affected forest AGB and NBP. Keywords: Attribution, Site-level Synthesis, Regional/Continental Synthesis 74: North American Vegetation Phenology Derived From Temporally Smoothed and Gap-Filled MODIS data

74: North American Vegetation Phenology Derived From Temporally Smoothed and Gap-Filled MODIS data Robert E Wolfe, NASA GSFC, robert.e.wolfe@nasa.gov (Presenting) Bin Tan, ERT @ NASA GSFC, btan@ertcorp.com Jeffery T Morisette, USGS, morisettej@usgs.gov Feng Gao, ERT @ NASA GSFC, fgao@ltpmail.gsfc.nasa.gov Gregory A Ederer, SAIC @ NASA GSFC, gederer@ltpmail.gsfc.nasa.gov Joanne M Nightingale, Inovim @ NASA GSFC, jaonne.m.nightingale@nasa.gov Jeffery A Pedelty, NASA GSFC, jeffery.a.pedelty@nasa.gov At seasonal to interannual time scales, vegetation phenology reflects dynamics of the Earth’s climate and hydrological regimes, and is diagnostic of coupling between the Earth’s biosphere and atmosphere. Reginal-scale phenology is useful for studies of seasonal and interannual variability in carbon exchange and vegetation-climate interactions over North America. Remote sensing provides a key means of measuring and monitoring phenology at continental scales. An enhanced TIMESAT algorithm was applied to the Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices (VIs) over North America continent to produce temporally and spatially smoothed and gap-filled data. A side benefit of the temporal fitting is a set of estimated phenology metrics. The phenology product contains twenty-five phenology parameters (Greenup date, Brown-down date, Integral VI values, etc.) and two ancillary parameters (Quality Assessment and Land cover type). The first three MODIS vegetation indices that this algorithm has been applied to are Leaf Area Index (LAI, 1km), Normalized Difference Vegetation Index (NDVI, 250m/500m), and Enhanced Vegetation Index (EVI, 250m/500m). Because of the use of the temporally and spatially smoothed and gap-filled MODIS data as input, the derived phonology product has a more complete spatial coverage than many other phenology products. The entire datasets are available through the web-based distribution system that includes many post-process options that are being used by the NACP and general Earth science community. In this poster we review the enhanced TIMESAT and related smoothing and phenology algorithms, describe the phenology product parameters, and compare the phenology metrics estimated from different VIs. Keywords: Diagnosis, Regional/Continental Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 75: Satellite based analysis of recent changes in ET and the terrestrial water balance over Canada and Alaska: Implications for vegetation productivity and the northern carbon cycle

75: Satellite based analysis of recent changes in ET and the terrestrial water balance over Canada and Alaska: Implications for vegetation productivity and the northern carbon cycle Ke Zhang, Flathead Lake Biological Station, The University of Montana, zhang@ntsg.umt.edu (Presenting) John S Kimball, Flathead Lake Biological Station, The Univeristy of Montana, johnk@ntsg.umt.edu (Presenting) E. H. Hogg, Northern Forestry Centre, Canadian Forest Service, Natural Resources Canada, thogg@nrcan.gc.ca Kyle C. McDonald, Jet Propulsion Laboratory, California Institute of Technology, kyle.mcdonald@jpl.nasa.gov

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Walter C. Oechel, Global Change Research Group, Biology Department, San Diego State University, oechel@sunstroke.sdsu.edu We applied a satellite remote sensing based evapotranspiration (ET) algorithm using AVHRR (GIMMS) NDVI, regionally corrected NCEP/NCAR reanalysis daily surface meteorology and NASA/GEWEX solar radiation inputs to assess spatial patterns and temporal trends in ET over Canada and Alaska from 1983 to 2005. We then analyzed associated changes in the regional water balance (P-ET), where precipitation (P) was defined from Global Precipitation Climatology Project (GPCP) monthly precipitation. We also assessed linkages between the regional water balance and vegetation net primary production (NPP) derived using a satellite remote sensing based production efficiency model. The satellite based ET results agree well (RMSE=21 W m-2, R2=0.76) with in situ measurements from northern grassland, boreal forest and tundra flux towers. The ET results showed generally positive trends over most of the region, and corresponded with regional warming, vegetation greening and increasing NPP. Negative ET trends occurred over 29% of the region, primarily in boreal forests of western and central Canada and southern Alaska. Approximately 66% of boreal forest and northern grassland exhibited below-average water balance during the growing season (May to October) from 2001 to 2003, of which 35% showed anomalies that were more than one standard deviation below 23-year average conditions. These recent large annual water deficits in boreal regions agree well with regional drought records and explain recent satellite observations of anomalous declines in annual NDVI and NPP. Our results also show that the regional water balance is changing in complex ways in response to global warming, with direct feedbacks to regional vegetation productivity, composition and distribution. This work was performed at the University of Montana and Jet Propulsion Laboratory, California Institute of Technology under contract to NASA. Keywords: Attribution, Site-level Synthesis, Regional/Continental Synthesis

Tools/Instruments/Data Posters76: Modeling and Synthesis Support for the North American Carbon Program

76: Modeling and Synthesis Support for the North American Carbon Program Robert B. Cook, Oak Ridge National Laboratory, cookrb@ornl.gov (Presenting) Wilfred M. Post, Oak Ridge National Laboratory, wmp@ornl.gov Peter E. Thornton, Oak Ridge National Laboratory, thorntonpe@ornl.gov Latha M. Baskaran, Oak Ridge National Laboratory, baskaranl@ornl.gov Lisa M. Olsen, Oak Ridge National Laboratory, olsenlm@ornl.gov Michele M. Thornton, Oak Ridge National Laboratory, thorntonpe@ornl.gov Carroll N. Curtis, Oak Ridge National Laboratory, cncurtis@crosslink.net Jerry Y. Pan, Oak Ridge National Laboratory, pany@ornl.gov Yaxing Wei, Oak Ridge National Laboratory, weiy@ornl.gov Steve L. Campbell, Oak Ridge National Laboratory, campbellsl1@ornl.gov The Modeling and Synthesis Thematic Data Center (MAST-DC) supports the North American Carbon Program (NACP) by providing data products and data management services needed for modeling and synthesis activities. A number of data products have been compiled for North America, including sub-pixel land-water content and daily meteorological data. Users can find these and additional data using an internet -based WebGIS system that enables users to browse, query, display, subset, and download spatial data using a standard web browser. As part of the interim NACP synthesis, MAST-DC is leading and supporting several grass-roots model-data comparison activities, including a site-level synthesis and a regional / continental synthesis. MAST-DC also provides data management support to the Mid-continental Intensive and Non-carbon dioxide Greenhouse Gas Interim Syntheses. MAST-DC Web Site: http://nacp.ornl.gov/mast-dc/ Keywords: Diagnosis, Attribution, Site-level Synthesis, Regional/Continental Synthesis, MCI Synthesis, non-CO2 Greenhouse Gases Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 77: The Wildland Fire Emissions Information System: Providing information for carbon cycle studies with open source geospatial tools

77: The Wildland Fire Emissions Information System: Providing information for carbon cycle studies with open source geospatial tools Nancy HF French, Michigan Tech Research Institute, Michigan Technological University, nancy.french@mtu.edu Tyler A Erickson, Michigan Tech Research Institute, Michigan Technological University, tyler.erickson@mtu.edu (Presenting) Donald McKenzie, Pacific Wildland Fire Sciences Lab, USDA Forest Service, dmck@u.washington.edu A major goal of the North American Carbon Program is to resolve uncertainties in understanding and managing the carbon cycle of North America. As carbon modeling tools become more comprehensive and spatially oriented, accurate datasets to spatially quantify carbon emissions from fire are needed, and these data resources need to be accessible to users for decision-making. Under a new NASA Carbon Cycle Science project, Drs. Nancy French and Tyler Erickson, of the Michigan Technological University, Michigan Tech Research Institute (MTRI), are teaming with specialists at the USDA Forest Service Pacific Northwest Research Center’s Fire and Environmental Research Applications (FERA) lab to provide information for mapping fire-derived carbon emissions to users. The project focus includes development of a web-based system to provide spatially resolved fire emissions estimates for North America in a user-friendly environment. The web-based Decision Support System will be based on a variety of open source technologies. The Fuel Characteristic Classification System (FCCS) raster map of fuels and MODIS-derived burned area vector maps will be processed using the Geographic Data Abstraction Library (GDAL) and OGR Simple Features Library. Tabular and spatial project data will be stored in a PostgreSQL/PostGIS, a spatially enabled relational database server. The browser-based user interface will be created using the Django web page framework to allow user input for the decision support system. The OpenLayers mapping framework will be used to provide users with interactive maps within the browser. In addition, the data products will be made available in standard open data formats such as KML, to allow for easy integration into other spatial models and data systems. Keywords: Attribution, Decision Support, Regional/Continental Synthesis, Software Tools, Instruments, Data Management, Programmatic

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Topics 78: Exploring Research Contributions of the North American Carbon Program using Google Earth

78: Exploring Research Contributions of the North American Carbon Program using Google Earth Peter Griffith, NASA GSFC / SSAI, peter.c.griffith@nasa.gov (Presenting) Lisa Wilcox, NASA GSFC / SSAI, lisa.e.wilcox@nasa.gov Amy Morrell, NASA GSFC / SSAI, amy.l.morrell@nasa.gov The central objective of the North American Carbon Program (NACP), a core element of the US Climate Change Science Program, is to quantify the sources and sinks of carbon dioxide, carbon monoxide, and methane in North America and adjacent ocean regions. The NACP consists of a wide range of investigators at universities and federal research centers. Although many of these investigators have worked together in the past, many have had few prior interactions and may not know of similar work within knowledge domains, much less across the diversity of environments and scientific approaches in the Program. Coordinating interactions and sharing data are major challenges in conducting NACP. The Google Earth Collection on the NACP website (www.nacarbon.org) provides a geographical view of the research products contributed by each core and affiliated NACP project. Other relevant data sources (e.g. AERONET) can also be browsed in spatial context with NACP contributions. Each contribution links to project-oriented metadata, or “project profiles”, that provide a greater understanding of the scientific and social context of each dataset and are an important means of communicating within the NACP and to the larger carbon cycle science community. Project profiles store information such as a project's title, leaders, participants, an abstract, keywords, funding agencies, associated intensive field campaigns, expected data products, data needs, publications, and URLs to associated data centers, datasets, and metadata. Data products are research contributions that include biometric inventories, flux tower estimates, remote sensing land cover products, tools, services, and model inputs / outputs. Project leaders are be asked to identify these contributions to the site level whenever possible, either through simple latitude/longitude pair, or by uploading a KML, KMZ, or shape file. After post-processing, research contributions are added to the NACP Google Earth Collection to facilitate discovery and use in synthesis activities of the Program.

Keywords: Software Tools, Instruments, Data Management, Programmatic Topics 79: Measuring Gross Ecosystem PRoduction Directly from Remote Sensing

79: Measuring Gross Ecosystem PRoduction Directly from Remote Sensing Forrest G Hall, UMBC/GSFC/JCET, fghall@ltpmail.gsfc.nasa.gov (Presenting) Thomas Hilker, U British Columbia, thilker@interchange.ubc.ca Nicholas C Coops, U British Columbia, nicholas.coops@ubc.ca We show that observed co-variations at sub-hourly time scales between the photochemical reflectance index (PRI) and canopy light use efficiency (LUE) over a Douglas-fir forest result directly from sub-hourly leaf reflectance changes in a 531 nm spectral window roughly 50 nm wide. We conclude then, that over a forest stand we are observing the direct effects of photosynthetic down-regulation on leaf-level reflectance at 531 nm. Key to our conclusion is our ability to simultaneously measure the LUE and reflectance of the Douglas-fir stand as a function of shadow fraction from the “hot spot” Measurements over a nearly 6 month period show that at a forest stand scale, only two NDRIs (both containing a band near 570 nm) vary with shadow fraction and are correlated with LUE; an NDRI with a band centered at 531 nm roughly 50 nm wide, and another near 705 nm. Therefore, we are able to conclude that only these two bands' reflectance differ between the sunlit and the shaded elements of the canopy. Their reflectance changes on time scales of a few minutes or less. These results demonstrate that the observed sub-hourly changes in foliage reflectance at 531 nm and 705 nm can only result from corresponding variations in photosynthetic rates. The importance of our results are as follows: (1) We show that variations in PRI with LUE are a direct result of rapid changes in foliage reflectance at 531 nm resulting from photosynthetic down-regulation, and can be observed at forest scales. (2) Our findings also suggest a new sensor and methodology for the direct retrieval from space of changes in forest LUE by measuring PRI as a function of shadow fraction using a multi-angle spectrometer simultaneously retrieving both shadow fraction and PRI.

Keywords: Site-level Synthesis 80: The Carbon-Land Model Intercomparison Project (C-LAMP): A Protocol and Metrics for Model-Data Comparison

80: The Carbon-Land Model Intercomparison Project (C-LAMP): A Protocol and Metrics for Model-Data Comparison Forrest M Hoffman, Oak Ridge National Laboratory, forrest@climatemodeling.org (Presenting) James T Randerson, University of California, Irvine, jranders@uci.edu Inez Y Fung, University of California, Berkeley, ifung@berkeley.edu Peter E Thornton, Oak Ridge National Laboratory, thorntonpe@ornl.gov Curtis C Covey, Lawrence Livermore National Laboratory, covey1@llnl.gov Gordon B Bonan, National Center for Atmospheric Research, bonan@ucar.edu Steven W Running, University of Montana, swr@ntsg.umt.edu The Carbon-Land Model Intercomparison Project (C-LAMP) began as a project to intercompare terrestrial biogeochemistry models in the Community Climate System Model (CCSM) framework. A collaboration between the CCSM Biogeochemsitry Working Group and the U.S. Dept. of Energy Scientific Discovery through Advanced Computing (SciDAC) Program, C-LAMP has evolved into an international protocol and set of metrics for grading the scientific performance of models by comparison with best-available observational datasets, from satellite to leaf-scale measurements. In the first set of experiments, the models are forced with an improved NCEP/NCAR reanalysis climate data set to examine the ability of the models to reproduce surface carbon and energy fluxes at multiple sites and to examine the influence of climate variability, prescribed atmospheric CO2 and nitrogen deposition on terrestrial carbon fluxes during the 20th century. An active atmosphere model is used in the second set of experiments with prescribed atmospheric CO2 concentrations. The objective of these simulations is to examine the effect

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of a coupled biosphere-atmosphere for carbon fluxes and climate during the 20th century. Presented will be results from these coupled experiments using two models, CLM3-CASA' and CLM3-CN, in the CCSM framework. Keywords: Diagnosis, Attribution, Prediction, Decision Support, Regional/Continental Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 81: News and Notes from the Land Processes Distributed Active Archive Center

81: News and Notes from the Land Processes Distributed Active Archive Center Calli B. Jenkerson, Land Processes Distributed Active Archive Center, jenkerson@usgs.gov (Presenting) David J. Meyer, Land Processes Distributed Active Archive Center, dmeyer@usgs.gov The Land Processes Distributed Active Archive Center (LP DAAC) was established as part of NASA's Earth Observing System (EOS) Data and Information System (EOSDIS) initiative to process, archive, and distribute land-related data collected by EOS sensors, thereby promoting the inter-disciplinary study and understanding of the integrated Earth system. The role of the LP DAAC includes the higher-level processing and distribution of ASTER data, and the distribution of MODIS land products derived from data acquired by the Terra and Aqua satellites. This poster provides status on important activities occurring at the LP DAAC. These include changes in data holdings, the transition from a near-line, tape-based archive to an on-line, disk-based archive, enhanced data discovery and delivery services, and the redesigned LP DAAC website. Keywords: Software Tools, Instruments, Data Management, Programmatic Topics 82: Spatial Data Services and Forest Inventory and Analysis Data

82: Spatial Data Services and Forest Inventory and Analysis Data Elizabeth LaPoint, USDA Forest Service, Forest Inventory and Analysis, elapoint@fs.fed.us (Presenting) The USDA Forest Service, Forest Inventory and Analysis program (FIA) collects, analyzes and reports on forest resource trends across the conterminous United States. The FIA database, containing information collected on over 125,000 permanent ground plots, can be used to produce estimates of the amount of forest acreage, forest volume, biomass, and other forest attributes. These measures are a valuable input into current North American Carbon Program research projects. FIA data, with its georeferenced plot locations, has great utility as a source of ground truth for remote sensing and modeling projects. Although FIA plot locations are protected from disclosure by the Food Security Act of 1985, there are methods of using the data that do not violate the law. Spatial Data Services (SDS) is a team dedicated to facilitating the use of FIA data by non-Forest Service researchers and organizations. SDS has been successful in meeting the needs of hundreds of researchers from a variety of institutions. Keywords: Software Tools, Instruments, Data Management, Programmatic Topics 83: Open-Path Gas Analyzer for Eddy Covariance Measurements of Methane Flux

83: Open-Path Gas Analyzer for Eddy Covariance Measurements of Methane Flux George Burba, LI-COR Biosciences, george.burba@licor.com Tyler Anderson, LI-COR Biosciences, tyler.anderson@licor.com Donatella Zona, San Diego State University, dzona@sciences.sdsu.edu Jessica Schedlbauer, Florida International Univesity, jschedlb@fiu.edu Steven Hastings, Barrow Arctic Science Consortium, steve.hastings@arcticscience.org Hiroki Ikawa, San Diego State University, hikawa@sunstroke.sdsu.edu Dayle McDermitt, LI-COR Biosciences, dayle.mcdermitt@licor.com (Presenting) Steven Oberbauer, Florida International Univesity, oberbaue@fiu.edu Walter Oechel, San Diego State University, oechel@sunstroke.sdsu.edu Gregory Starr, Alabama State University, gstarr@bama.ua.edu Cove Sturtevant, San Diego State University, csturtevant@projects.sdsu.edu Liukang Xu, LI-COR Biosciences, liukang.xu@licor.com Methane is an important greenhouse gas with a warming potential of about 23 times that of carbon dioxide over a 100-year cycle (Houghton et al., 2001). Measurements of methane fluxes from the terrestrial biosphere have mostly been made using flux chambers, which have many advantages, but are discrete in time and space and may disturb surface integrity and air pressure. Open-path analyzers offer a number of advantages for measuring methane fluxes, including undisturbed in-situ flux measurements, spatial integration using the Eddy Covariance approach, zero frequency response errors due to tube attenuation, confident water and thermal density terms from co-located fast measurements of water and sonic temperature, and remote deployment due to lower power demands in the absence of a pump. The prototype open-path methane analyzer is a VCSEL (vertical-cavity surface-emitting laser)-based instrument. It employs an open Herriott cell and measures levels of methane with RMS noise below 6 ppb at 10 Hz sampling in controlled laboratory environment. Field maintenance is minimized by a self-cleaning mechanism to keep the lower mirror free of contamination. Eddy Covariance measurements of methane flux using the prototype open-path methane analyzer are presented for the period between 2006 and 2008 in three ecosystems with contrasting weather and moisture conditions: (1) Fluxes over a short-hydroperiod sawgrass wetland in the Florida Everglades were measured in a warm and humid environment with temperatures often exceeding 25oC, variable winds, and frequent heavy dew at night; (2) Fluxes over coastal wetlands in an Arctic tundra were measured in an environment with frequent sub-zero temperatures, moderate winds, and ocean mist; (3) Fluxes over pacific mangroves in Mexico were measured in an environment with moderate air temperatures high winds, and sea spray.

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Presented eddy covariance flux data were collected from a co-located prototype open-path methane analyzer, LI-7500, and sonic anemometer at a 10 Hz rate. Data were processed using EdiRe software following standard FluxNet methodology, including stationarity tests, frequency response, and Webb-Pearman-Leuning density terms. Keywords: Attribution, Software Tools, Instruments, Data Management, Programmatic Topics 84: Mountaintop Inter-Comparison Of NOAA/ESRL Trace Gas Measurement Systems

84: Mountaintop Inter-Comparison Of NOAA/ESRL Trace Gas Measurement Systems D. Neff, NOAA/ESRL, CIRES, don.neff@noaa.gov (Presenting) Results from field inter-comparison experiments of several different trace-gas measurement systems in current use at the National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA/ESRL) will be presented. Near-simultaneous real air samples were obtained near the summit of Mt. Evans (elevation ~ 4350 m; located ~ 50 miles west of Denver, Colorado) using the NOAA/ESRL Programmable Flask Package (PFP) sampling systems and the manual 2.5L flask portable sampler (PSU). This general PSU design has been in use for more than 10 years in the ESRL/GMD Cooperative Global Air Sampling Network, and network measurements from PSU samples have been well characterized. In addition, inter-comparisons of continuous measurements were obtained for CO2 and CH4 for a subset of these samples. The mixing ratios of six atmospheric trace species (CO2, CH4, CO, H2, N2O, SF6) were compared from these flask systems to provide estimates of measurement uncertainties associated with the PFP systems for each of these six species and to look for potential biases between all sampling systems. The field location was chosen in order to sample atmospheric air relatively free of influence from nearby sources or sinks, with low variability over the sampling timescale, in order to provide for better sample inter-comparison. Keywords: Software Tools, Instruments, Data Management, Programmatic Topics 85: Developing an accuracy assessment protocol for Forest Inventory and Analysis (FIA) geospatial datasets

85: Developing an accuracy assessment protocol for Forest Inventory and Analysis (FIA) geospatial datasets Rachel Riemann, USFS Northern Research Station, rriemann@fs.fed.us (Presenting) Barry Tyler Wilson, USFS Northern Research Station, barrywilson@fs.fed.us Forest Inventory and Analysis (FIA) is in the process of developing geospatial datasets of forest characteristics such as biomass and tree species importance and is in need of standardized methods for assessing these datasets. Such information would improve dataset utility by contributing a documented description of dataset characteristics and its limits of use for particular purposes and at particular scales. As FIA and others continue to generate new models and geospatial datasets of forest characteristics, there is a need for a standard way to assess where and in what ways the two datasets are different and which may be better, either overall or for a particular purpose. The accuracy assessment conducted in this study is a comparative assessment of estimates derived from the geospatial datasets vs. the FIA plot data, as inventory data will frequently be the only extensive dataset available for such assessments. Differences in sample unit size and sampling intensity are taken into account in the assessment. Geospatial datasets are used for a wide variety of purposes--e.g. for point estimation, area summaries, landscape pattern assessments, overlay with other spatial datasets where locational accuracy is critical, and stratification--and the suite of assessment metrics assembled should respond to as many of these as possible. In this study we examine a modeled geospatial datasets in both Minnesota and New York. Assessments include analyzing distributions of values, predictions at point and area locations, and assessments by region to distinguish variations in accuracy across the dataset. Results are examined for interpretability, exhaustiveness, effectiveness at highlighting differences, and utility of the information provided for determining dataset appropriateness for a particular task. Keywords: Diagnosis, Decision Support, Software Tools, Instruments, Data Management, Programmatic Topics 86: Accurate retrievals of forest structure and biomass from the Echidna® ground-based, upward-scanning lidar

86: Accurate retrievals of forest structure and biomass from the Echidna® ground-based, upward-scanning lidar Alan Strahler, Boston University,, alan@bu.edu Curtis Woodcock, Boston University, curtis@bu.edu Crystal Schaaf, Boston University, schaaf@bu.edu (Presenting) David Jupp, CSIRO, david.jupp@csiro.au Darius Culvenor, CSIRO, darius.culvenor@csiro.au Glenn Newnham, CSIRO, glenn.newnham@csiro.au Wenge Ni-Meister, Hunter College of CUNY, wenge.ni-meister@hunter.cuny.edu Feng Zhao, Boston University, zhao26@bu.edu Tian Yao, Boston University, tianyao@bu.edu Xiaoyuan Yang, Boston University, xiaoyuan@bu.edu A new ground-based lidar technology, Echidna®, provides the ability to inventory the structural properties of forests rapidly and accurately using a hemispherical-scanning, near-infrared laser with full-waveform signal digitizing. Work from New South Wales (Australia), New England, and California’s Sierra Nevada Range shows that the Echidna® Validation Instrument (EVI), the first such lidar so constructed, can accurately retrieve such variables as canopy height, mean tree diameter, tree stem count density, basal area, biomass, leaf area index, and foliage profile from stands ranging from Australian eucalypts to mature Eastern hardwoods to California conifer stands. Moreover, by registering overlapping scans from different viewpoints using tomographic techniques, it is possible to construct a 3-D model of the forest, allowing direct measurement of both above-ground wood and branch volume and leaf scattering volume for estimates of both standing and green biomass. Structural parameters of forest stands are normally retrieved with accuracies of 5-10 percent, as compared to manual measurements. Standing biomass also requires a separate, quick sample of larger stems to determine the proportions of the stand in hardwoods or softwoods. The Echidna® concept and the Echidna® Validation Instrument were designed and developed by Australia’s CSIRO. Echidna® lidar data and structural parameter retrievals for a number of sites will be available at the Oak Ridge DAAC. Keywords: Diagnosis, Software Tools, Instruments, Data Management, Programmatic Topics

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87: Non-Destructive Belowground Carbon Observations from Organic Soils to Mine Overburden: Recent Progress

87: Non-Destructive Belowground Carbon Observations from Organic Soils to Mine Overburden: Recent Progress Lucian Wielopolski, Brookhaven National Laboratory, lwielo@bnl.gov (Presenting) The Earth’s carbon budget is in imbalance, with North America (Canada, the USA, and Mexico) being a significant contributor to it. However, some scientific evidence points to the vegetation and soils of this region as a possible important sink for atmospheric CO2 , thus partially mitigating its generation from fossil-fuel sources; nevertheless , the contribution of North America to that sink is highly uncertain. Understanding the North American carbon budget, both sources and sinks, is critical to meeting the goal of the U.S. Climate Change Science Program, viz., providing the best recent scientific information to support both public discussions of, and decision-making by the government and the private sector on key climate-related issues. Inelastic Neutron Scattering (INS) technology offers a rapid non-destructive method for analyzing the soil’s content of carbon and other nutrients. It can statically probe large volumes of soil, >200 kg, or alternatively, scan arbitrarily large areas. These unique INS capabilities enable true sequential measurements at the same spot, and provide an interface for integrating all above-ground calculations and measurements of carbon flux, including remote sensing, with direct below-ground carbon measurements at the same pixel size. INS also revolutionizes the present sampling paradigm on the landscape or regional scales, while simultaneously reducing the required effort. We applied INS in a series of detailed field studies to demonstrate its capability to collect measurements in highly variable landscapes and soil types. They varied from organic soils with very low bulk density up to the rocky overburdens of active strip-mining lands. Similarly, scans were undertaken on flat fields, and over highly slopped landscapes. This paper summarizes our results, and discusses the present status of the INS system and future tasks. Keywords: Diagnosis, Decision Support, Software Tools, Instruments, Data Management, Programmatic Topics

Prediction Posters 88: Simulation of Terrestrial Ecosystem Dynamics, Past and Future: A Nested Scale Experiment (NeScE), a Mythical Beast

88: Simulation of Terrestrial Ecosystem Dynamics, Past and Future: A Nested Scale Experiment (NeScE), a Mythical Beast Ronald P Neilson, USDA Forest Service, neilson@fsl.orst.edu James M Lenihan, USDA Forest Service, lenihan@fsl.orst.edu Dominique Bachelet, Oregon State University, bachelet@fsl.orst.edu (Presenting) Raymond J Drapek, USDA Forest Service, drapek@fsl.orst.edu Chris Daly, Oregon State University, daly@nacse.org John R Wells, Oregon State University, john.r.wells@oregonstate.edu Maureen McGlinchy, Oregon State University, maureen.mcglinchy@oregonstate.edu Brendan Rogers, Oregon State University, brendan.rogers@oregonstate.edu Guy Pinjuv, Oregon State University, guy.pinjuv@oregonstate.edu Patrick Gonzalez, The Nature Conservancy, pgonzalez@tnc.org Accurate forecasting of the potential impacts of climate change on terrestrial ecosystems using Dynamic General Vegetation Models (DGVMs) is of critical importance for numerous reasons, depending in part, on the scale of interest. Global to continental-scale carbon balance and vegetation change could enhance or diminish climate change over the next century via trace gas and other biophysical feedbacks. These feedbacks are of critical concern for international negotiations on the controls of greenhouse gas emissions. However, at landscape to regional scales land managers are deeply concerned about potential forest dieback, changes in species composition, possible catastrophic disturbances and decline or changes in ecosystem services. Data to validate DGVMs are taken at various scales from site measurements to global (trace gases, remote sensing). As with climate models, DGVMs are based on fundamental concepts and, in theory, should operate at all spatial and temporal scales. However, limitations in basic knowledge and computational resources force the use of ever more coarse grid resolutions at larger spatial scales, forcing some processes to be ‘parameterized’, rather than explicitly simulated. Yet, smaller domains with higher resolution may require explicit simulation of processes, such as dispersal, fire spread and hydrologic routing. We present a Nested Scale Experiment (NeScE) from global to landscape and from 1900 to the present of observed monthly climate data and on to 2100 under 9 future climate scenarios (3 GCMs X 3 SRES Emissions Scenarios). Using the MC1 DGVM, we explore potential feedbacks, impacts and uncertainties associated with these multi-scale simulations. Consistency of impacts and feedbacks (both past and future), as well as sources of uncertainty, will be explored across four spatial resolutions in this preliminary investigation and presented for use by both scientists and natural resource managers. We present NeScE as an open-investigator framework for model testing, validation and impacts and feedback assessments. Keywords: Diagnosis, Attribution, Prediction, Decision Support, Regional/Continental Synthesis 89: Incorporating landscape-scale edaphic variation into regional ecosystem forecasts using ED2

89: Incorporating landscape-scale edaphic variation into regional ecosystem forecasts using ED2 Michael Dietze, University of Illinois, Urbana-Champaign, mdietze@illinois.edu (Presenting) Paul Moorcroft, Harvard University, paul_moorcroft@harvard.edu Andrew Richardson, University of New Hampshire, andrew.richardson@unh.edu Ecologists have long recognized consistent vegetation patterns at the landscape-scale due to edaphic variation in topography, hydrology, and soils. Despite the recognition that different portions of the landscape function differently and may respond differently to climate change (e.g. upslope migration), current regional and global scale vegetation models do no capture this heterogeneity. In general, the scale of variability (10-1000m) is orders of magnitude finer than model grid resolution (0.25-1 degree). We report on an approach to capture subgrid spatial heterogeneity in regional models that accounts for topographic variability in soils, microclimate, solar radiation, and lateral hydrology. We are validating this approach in the Ecosystem Demography (ED v2.1) model using a combination of data from the the Harvard Forest, Bartlett Experimental Forest, and Howland Forest eddy-covariance towers (daily-interannual ecosystem fluxes), the Hubbard Brook experimental

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water sheds (hydrology, multidecadal vegetation dynamics and heterogeneity), and the USFS Forest Inventory and Analysis (regional and edaphic gradients in growth and mortality). We will present results on the model's ability to capture watershed hydrology, ecosystem fluxes, and edaphic gradients in vegetation dynamics for New England. Also, unlike empirical studies where edaphic variables are often highly correlated, the mechanistic modeling approach allows us to estimate the separate contributions of different edaphic factors. Using this approach we will present a partitioning of the effects of microclimate, lateral hydrology, and hillshading on the carbon and water fluxes of New England. Keywords: Attribution, Prediction, Site-level Synthesis 90: N Limitation and Terrestrial C Storage: Scaling from microns to the globe through data synthesis and modeling.

90: N Limitation and Terrestrial C Storage: Scaling from microns to the globe through data synthesis and modeling. Adrien C. Finzi, Boston University, afinzi@bu.edu (Presenting) Peter E. Thornton, Oak Ridge National Lab, thorntonpe@ornl.gov Christine L. Goodale, Cornell University, clg33@cornell.edu Nitrogen (N) limitation is widespread in the terrestrial biosphere, placing a major constraint on carbon sequestration. Although the science of the N cycle has been a major avenue of research in biogeochemistry for well over three decades, the implementation of global change experiments has greatly advanced our understanding of the processes regulating the N cycle. As a result of these advances, N limitation is increasingly being represented in coupled climate-carbon cycle models, models that have traditionally been driven solely by biophysical attributes of the earth system. In this plenary, we propose to evaluate the empirical and modeling bases for N limitation in terrestrial ecosystems. We will focus specifically on biotic (e.g. belowground carbon allocation) and abiotic (e.g. climate variability, N deposition) factors that tend exacerbate or relax N limitation, and analyze their consequences for C storage with rising concentrations of carbon dioxide and a changing climate. We will use a series of well-characterized case studies to address these questions, drawing from global change experiments, eddy flux data sets, and the results of model simulations. This analysis will show (1) that small spatial and temporal scale belowground processes have a major impact on regional to global scale exchanges of carbon dioxide between the atmosphere and biosphere, and (2) that the implementation of a new conceptual model of the terrestrial N cycle may improve the accuracy of C storage estimates for the 21st century. Keywords: Attribution, Prediction, Site-level Synthesis, Regional/Continental Synthesis 91: Towards detection of the changing North America carbon sink

91: Towards detection of the changing North America carbon sink Inez Fung, UC Berkeley, ifung@berkeley.edu (Presenting) Nir Krakauer, CCNY, nir@ce.ccny.cuny.edu Zan Stine, UC Berkeley, zan@atmos.berkeley.edu Abby Swann, UC Berkeley, aswann@atmos.berkeley.edu The US is strong emitter and a weak or neutral sink of anthropogenic CO2. This paper summarizes the signatures of the changing North American sink and presents challenges to top-down inversions, from changes in fossil fuel CO2 emission patterns and atmospheric circulation, to changing dynamics of terrestrial ecosystems. We present an analysis of CO2 flux data from the Ameriflux network and suggest improvements to terrestrial carbon models coupled to global climate models. Keywords: Diagnosis, Attribution, Prediction, Regional/Continental Synthesis 92: Thermokarst dynamics and related carbon cycling in ice-rich permafrost in NW Alaska

92: Thermokarst dynamics and related carbon cycling in ice-rich permafrost in NW Alaska Guido Grosse, University of Alaska Fairbanks, ffgg1@uaf.edu (Presenting) Katey Walter, University of Alaska Fairbanks, ftkmw1@uaf.edu Lawrence Plug, Dalhousie University, ljp@dal.ca Vladimir Romanovsky, University of Alaska Fairbanks, ffver@uaf.edu Mary Edwards, University of Alaska Fairbanks, M.E.Edwards@soton.ac.uk Lee Slater, Rutgers University, lslater@andromeda.rutgers.edu Formation, growth, and drainage of thermokarst lakes in ice-rich permafrost deposits are important factors of biogeochemical dynamics in extent Arctic lowlands. An overall decrease in permafrost stability will impact the spatial and temporal dynamics of such lakes and will change biogeochemical processes related to thermokarst. In this project we use a broad array of methods (remote sensing, biogeochemistry, paleoenvironmental analysis, geomorphology, geophysics, numerical modeling) to assess and analyze the development of thermokarst lakes in thaw-vulnerable icy permafrost regions of Siberia and Alaska and their relevance for the Arctic carbon cycle. This presentation will focus on first-year results from our study sites on the northern Seward Peninsula, Alaska. The study region is characterized by continuous permafrost, a highly dissected and dynamic thermokarst landscape, uplands of Late Pleistocene permafrost deposits with high excess ice contents, and a large total volume of permafrost-stored carbon. These ice-rich deposits are highly vulnerable to permafrost degradation forced by climate warming or other surface disturbance. We will discuss the spatial and temporal patterns of methane emissions from thermokarst lakes in the region, examine processes resulting in sink/source changes, and identify potential surprises in the carbon cycling of Arctic thermokarst lakes. Keywords: Diagnosis, Attribution, Prediction 93: Interactive effects of disturbance, rising CO2 concentrations, nitrogen deposition and climate on carbon cycle dynamics of US West-Coast forests

93: Interactive effects of disturbance, rising CO2 concentrations, nitrogen deposition and climate on carbon cycle dynamics of US West-Coast forests Tara Hudiburg, Oregon State University, tara.hudiburg@oregonstate.edu (Presenting)

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Peter Thornton, ORNL, thorntonpe@ornl.gov Beverly Law, Oregon State University, bev.law@oregonstate.edu US West-Coast forests sequester significant amounts of atmospheric carbon dioxide and have the potential to either increase or decrease carbon storage under future climate and management scenarios (Hudiburg et al. 2008). Several million forested acres are at risk of catastrophic fire and management practices to reduce risk through forest thinning and removal of slash have been implemented or suggested (1072 2005). The impact of periodic partial disturbance through this type of management on carbon dynamics has not been determined. Accurate prediction of carbon dynamics will require understanding the interactions of partial disturbance with increasing levels of atmospheric CO2, climate change, and nitrogen deposition. By modeling the impacts of each factor separately and together, the contribution of each can be quantified. Data from AmeriFlux, NACP, and FIA sites were used to parameterize and validate output from the Community Land Model-CN version 3.6 (CLM-CN 3.6, Thornton and Zimmermann 2007). Periodic and catastrophic disturbances were the most influential factors on total ecosystem carbon and net ecosystem exchange (NEE). Increasing C02 and nitrogen deposition had little to no effect on NEE and total ecosystem carbon for the period from 1890 to 2005, while climate may be more influential in typically drier sites. Nitrogen deposition has been historically low (approximately 3 kgN/hectare) in the Pacific Northwest. The use of FIA, AmeriFlux, and NACP site data proved useful both in validating model output and providing high temporal and spatial resolution climate data for driving the model fluxes. Implementation of a multi-age class structure in CLM-CN would improve the model’s ability to capture the effects of partial disturbance. Results and model improvements from this study should allow for a comprehensive evaluation of the net carbon balance for the entire region. 1. Hudiburg, T., B. E. Law, D. P. Turner, J. Campbell, D. Donato, and M. Duane. 2008. Carbon dynamics of Oregon and Northern California forests and potential land-based carbon storage. Ecological Applications. In Press. 2. Oregon Senate Bill 1072. 73rd OREGON LEGISLATIVE ASSEMBLY--2005 Regular Session. 3. Thornton, P. E., and N. E. Zimmermann. 2007. An improved canopy integration scheme for a land surface model with prognostic canopy structure. Journal of Climate 20:3902-3923. Keywords: Attribution, Prediction, Decision Support, Site-level Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 94: Black Carbon Stocks as Carbon Sinks in Soils of the United States

94: Black Carbon Stocks as Carbon Sinks in Soils of the United States Verena Jauss, Cornell University, sj384@cornell.edu Johannes Lehmann, Cornell University, cl273@cornell.edu (Presenting) Peter Woodbury, Cornell University, pbw1@cornell.edu Evelyn Krull, CSIRO, evelyn.krull@csiro.au To explain the role of Black Carbon (BC) as a pool for CO2 sequestration in North American ecosystems, it is necessary to acquire information on the contribution of BC to Soil Organic Carbon (SOC) across different climatic regions. BC represents one of the few ways that carbon can be rendered relatively inert. Thus, there is a strong potential for BC to act as a significant C sink from the more rapid bio-atmospheric C cycle to the slower (long term) geological C cycle. Recent investigations indicated that up 35% of the total soil organic C in some agricultural soils of the USA consisted of BC. In spite of these findings, most recent carbon related studies focus merely on non-BC components and therefore neglect to address the long term ecological significance of BC stock changes in the global C cycle. Additionally, most available BC data is largely restricted to topsoils. If BC forms a larger than currently anticipated pool of SOC, information about pool size must be included in General Circulation Models (GCM) for prediction of climate change. To address these knowledge gaps, our project is concerned with establishing a first inventory of BC stocks in surface and subsurface soils across the U.S. using both NSF supported Long Term Ecological Research (LTER) sites as well as a national soil sampling effort by the U.S. Geological Survey. The latter consists of samples from A- and C-Horizons at over 13,000 selected sites distributed at a density of one site per 1,600km2. Specifically, our research attempt to address: (1) the changes in BC stocks in undisturbed ecosystems as well as the impacts of human intervention such as land cover changes and fire prevention measures; (2) the contribution of subsoils to total BC stocks in both native and managed ecosystems across representative landscapes throughout the U.S.; and (3) the landscape controls over BC stocks. To analyze the samples, we are using mid-infrared (MIR) and partial least-squares (PLS) analysis in conjunction with UV-NMR spectroscopic techniques. Since it is difficult to estimate the effects of positive and negative feedbacks within ecosystems while also considering spatial and temporal scales of the processes concerned, we are going to set up a GIS database of BC stocks and related data for the United States that will assist us in modeling said processes and allow us to investigate the nature of BC stocks over a range of climates as well as land-use and landscape features in the United States. Keywords: Diagnosis, Attribution, Prediction, Decision Support, Regional/Continental Synthesis 95: Quantifying variations of sources and delivery of organic carbon from continental US induced by multiple environmental stresses by using integrated system of the Dynamic Land Ecosystem Model and Nutrient Export (DLEM-NE)

95: Quantifying variations of sources and delivery of organic carbon from continental US induced by multiple environmental stresses by using integrated system of the Dynamic Land Ecosystem Model and Nutrient Export (DLEM-NE) Mingliang Liu, Auburn University, liuming@auburn.edu (Presenting) Hanqin Tian, Auburn University, tianhan@auburn.edu Chi Zhang, Auburn University, zhangch@auburn.edu Guangsheng Chen, Auburn University, chengu1@auburn.edu Bray Beltran Villarreal, Auburn University, bjb0008@auburn.edu Xiaofeng Xu, Auburn University, xuxiaof@auburn.edu Chaoqun Lv, Auburn University, czl0003@auburn.edu Wei Ren, Auburn University, renwei1@auburn.edu The magnitude of carbon export from land to aquatic ecosystem and coastal region is far from uncertain, which has been identified as a major gap in our understanding of the global carbon budget. To quantify the fluxes of organic carbon from land to aquatic ecosystems and underlying mechanisms, we have developed an integrated ecosystem model (DLEM-NE) by incorporating Nutrient Export module into the Dynamic land Ecosystem Model.

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By coupling the processes of biogeochemistry, hydrology, nutrient leaching, water transport, and vegetation dynamics, the DLEM-NE model is capable of assessing the impacts of natural and anthropogenic driving forces on organic carbon export from terrestrial system. To assess the export of organic carbon from conterminous US to aquatic system, we have constructed spatially explicit historical data sets of land-use/land-cover, land management, and nitrogen deposition by linking high-resolution remote sensing products, survey data, point emission data sets and land use model. Then we have used those spatial data sets as input of DLEM-NE for investigating how changes in climate, land use and atmospheric composition have affected organic carbon fluxes from land to sea. Simulation results have been validated against field observations at sites, river and watersheds across conterminous US. Simulation results have indicated that the spatial and temporal variations in organic carbon loading to the aquatic ecosystem are in correspondent to the responses of terrestrial ecosystems to multiple changes in climate, atmospheric compositions and land use To accurately estimate organic carbon export from land to coastal, therefore, we need to better address quantitative linkage between terrestrial ecosystem processes and coastal system. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis, Coastal Synthesis 96: Atmospheric Methane Contributions From Fractured Bedrock Aquifers

96: Atmospheric Methane Contributions From Fractured Bedrock Aquifers D.L. Marrin, Water Sciences & Insights, watersciences@earthlink.net (Presenting) Groundwater is not normally considered as an important contributor of atmospheric methane because the organic carbon content of aquifers is too low to sustain significant methanogenesis. Also, groundwater-generated methane partitions into the gas phase of the overlying soil, where it either dissolves in the pore water or is oxidized to carbon dioxide by methanotrophs. There are, however, localized conditions (related to human activities and hydrogeologic conditions) under which atmospheric contributions of groundwater-generated methane occur at the ground surface. Storing and transporting liquid petroleum products in the subsurface has resulted in the local introduction of high concentrations of degradable organic carbon and the creation of redox conditions that favor methanogenesis over more oxidative biodegradation pathways. Groundwater overlain by fractured bedrock, rather than by unconsolidated porous media, creates a situation where CH4 migrates through discrete fractures, thus limiting the soil volume and the surface area available for methanotrophic activity. The spatial distribution of methane in thin surface soils overlying bedrock suggests that CH4 migrates via fracture networks and that CH4 oxidation is a factor of about 50 less than that measured in typical unconsolidated soils. Atmospheric flux rates associated with contaminated bedrock aquifers were on the order of several grams of carbon (as CH4) per square meter, which is less than that reported for well documented sources (e.g., rice paddies) and probably represents a minor worldwide contribution. Nonetheless, these aquifers can represent an important localized source, can shift soils from a sink to a source of methane, and can permit petroleum products to load carbon (as biogenic CH4 and CO2) to the atmosphere without ever being combusted.

Keywords: Prediction 97: Carbon Consequences of Regional Land Cover Changes in North America

97: Carbon Consequences of Regional Land Cover Changes in North America Chrisotpher S.R. Neigh, SSAI, GSFC-NASA, christopher.s.neigh@nasa.gov (Presenting) Nuno Carvalhais, Department of Environmental Science and Engineering, New University of Lisbon, ncarvalhais@gmail.com G Jim Collatz, GSFC-NASA, jim.collatz@nasa.gov Compton Jim Tucker, GSFC-NASA, USGCRP, tucker@usgcrp.gov We present a modeling approach to investigate fine-scale carbon consequences of ecosystem disturbance and land cover change dynamics in regions of increased NDVI in North America, that have altered terrestrial patterns of net ecosystem productivity from 1982-2005. Terrestrial carbon fixation and respiration is substantially affected by components of land-cover/land-use change which may not be accounted for in coarse-scale simulations. The Carnegie-Ames- Stanford approach (CASA) biosphere model was run with changing fractional land cover to simulate seasonal patterns in net plant carbon fixation, biomass and nutrient allocation, litterfall, soil nitrogen mineralization, and microbial CO2 production. Carbon reallocation was based on anthropogenic and abiotic disturbances identified with multi-resolution multi-temporal remote sensing data (Landsat, IKONOS, and aerial photography). We simulated expansion of irrigated agriculture, herbivorous insect outbreaks followed by logging and subsequent recovery, and fire with subsequent recovery. Simulations found altered allocation of carbon in ecosystems with disturbance as compared to simulations without fine-scale land cover change data, and marked difference in carbon balance upwards of 30 g C m-2 yr-1 can occur when accounting for fine-scale disturbance aggregated across a region during a 24 year (1982-2005) period. Altered carbon pathways represent spatially complex transient pools of carbon in North American vegetation perturbed by abiotic and anthropogenic land cover conversions which contributed to the terrestrial Northern Hemisphere sink in locations of increased NDVI. Coarse resolution simulations could well fail to identify complex land cover processes which impact regional carbon balance. Keywords: Diagnosis, Attribution, Prediction, Regional/Continental Synthesis 98: Nitrogen Limitation is Reducing the Enhancement of NPP by Elevated CO2 in a Deciduous Forest

98: Nitrogen Limitation is Reducing the Enhancement of NPP by Elevated CO2 in a Deciduous Forest Richard J Norby, Oak Ridge National Laboratory, rjn@ornl.gov (Presenting) Jeffrey M Warren, Oak Ridge National Laboratory, warrenjm@ornl.gov

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Colleen M Iversen, Oak Ridge National Laboratory, iversencm@ornl.gov Belinda E Medlyn, Macquarie University, bmedlyn@bio.mq.edu.au Ross E McMurtrie, University of New South Wales, r.mcmurtrie@unsw.edu.au Accurate model representation of the long-term response of forested ecosystems to elevated atmospheric CO2 concentrations (eCO2) is important for predictions of future concentrations of CO2. A synthesis of forest FACE experiments reported a 23% increase in NPP in eCO2, and this result has been used as a model benchmark. Here, we provide new evidence from a FACE experiment in a deciduous forest in Tennessee that N limitation has significantly reduced the stimulation of NPP by eCO2. The Liquidambar styraciflua stand has been exposed to current ambient atmospheric CO2 or air enriched with CO2 to 550 ppm since 1998. Results from the first 6 years of the experiment indicated that NPP was significantly and consistently enhanced by eCO2, but the enhancement has declined from 24% in 2001-2003 to 9% in 2007. The diminishing response to eCO2 since 2004 coincides with declining NPP in ambient CO2 plots. The steady decline in forest NPP is closely related to changes in the N economy, as evidenced by declining foliar N concentrations. There is a strong linear relationship between foliar [N] and NPP, and the steeper slope in eCO2 indicates that the NPP response to eCO2 should diminish as foliar N declines. Increased fine-root production and root proliferation deeper in the soil have sustained N uptake, but not to an extent sufficient to benefit aboveground production. As predicted by models, photosynthesis and the response of photosynthesis to eCO2 have also declined with declining foliar [N], providing mechanistic support for the stand-level observations. It is not yet clear whether foliar [N] and NPP will continue to decline or have reached a new steady state indicative of long-term forest response to eCO2. Keywords: Prediction 99: CO2- Enhanced Precipitation Use Efficiency and Carbon Sequestration in Terrestrial Ecosystems of North America

99: CO2- Enhanced Precipitation Use Efficiency and Carbon Sequestration in Terrestrial Ecosystems of North America Yude Pan, Northern Global Change Program, USDA Forest Service, Newtown Square, PA, ypan@fs.fed.us (Presenting) Richard Birdsey, Northern Global Change Program, USDA Forest Service, Newtown Square, PA, rbirdsey@fs.fed.us Kevin McCullough, Northern Global Change Program, USDA Forest Service, Newtown Square, PA, kevinmccullough@fs.fed.us Robert Nowak, Department of Natural Resources & Environmental Science, University of Nevada-Reno, Reno, NV, nowak@cabnr.unr.edu Ram Oren, Nicholas School of the Environment, Duke University, Durham, NC, ramoren@duke.edu Free-air CO2 Enrichment (FACE) experiments provided valuable information and insight to understand responses of terrestrial ecosystems to elevated atmospheric CO2 concentration. Based on FACE experiment data cross ecosystems from desert, grasslands to warm temperate forests, we developed a new index, enhanced precipitation use efficiency (EPUEp), to examine the relationships between CO2 enhancement of aboveground net primary productivity (APP) and precipitation. A new pattern emerged to indicate that elevated CO2 enhances precipitation use efficiency of ecosystems and such an effect consistently declines from drier climates to the wetter end of the precipitation gradient. A particular advantage of this newly developed index (EPUEp) is that we were able to develop a statistically significant equation universally fit for the data derived from the FACE studies. The equation also provides a solid method to calculate APP enhancement of various ecosystems in a relatively accurate fashion. To place the result in context, we apply spatial datasets of precipitation and baseline APP at 0.5o resolution for North America and calculate the potential effect of enhanced precipitation use efficiency on the carbon sequestration in the North American terrestrial ecosystems under a high CO2 environment. To reflect the impact of chronically elevated atmospheric CO2 concentration through several decades (1950s-2000s) in the past, we also employ the Michaelis-Menton function to scale the effect of CO2 concentration on plant productivity based on the CO2 enrichment levels of FACE experiments. Thereby, we estimate the strength of C sequestration that likely has happened in terrestrial ecosystems of North America, which was singly attributed to CO2 “fertilization” effect. Keywords: Attribution, Prediction, Site-level Synthesis, Regional/Continental Synthesis 100: Climate Change Effects on Vegetation Distribution and Carbon Storage in the Pacific Northwest

100: Climate Change Effects on Vegetation Distribution and Carbon Storage in the Pacific Northwest Brendan M Rogers, Oregon State University, brog107@gmail.com (Presenting) Ronald P Neilson, USDA Forest Service, neilron1@gmail.com Predicting the vegetation distributions and carbon budgets of the U.S. Pacific Northwest is difficult because of steep topographic, edaphic, and meteorological gradients. However, given the magnitude of predicted 21st century climate changes, understanding the region’s sensitivities to changes in temperature and precipitation is of utmost importance. To assess the Pacific Northwest’s sensitivity to climate change, we downscaled data from nine general circulation model simulations (three GCMs each run at three CO2 emission scenarios) to an 800-meter resolution grid spanning the western two-thirds of Oregon and Washington. We then used MC1, a dynamic vegetation model, to simulate changes in vegetation types and carbon loads during the projected 21st century climates. MC1 simulates competition for water, nutrients, and light between plant functional types and uses a biogeographical rule base to classify vegetation type. It also contains a detailed and interactive fire module. Changes in ecosystem spatial extent and carbon storage are shown to be non-linear functions of temperature and precipitation forecasts. Responses differ by ecoregion and climatic regime. Two hydrologic factors associated with higher temperatures interact to be dominant mechanisms of change: (1) an increasing synchrony between precipitation and the beginning of the Pacific Northwest growing season, and (2) earlier snowmelt. Both act to increase the available water content at the start of the growing season but also increase the drought stress later in the summer. Keywords: Diagnosis, Attribution, Prediction, MCI Synthesis 101: A National Soil Carbon Network: Concept, organization, and participation.

101: A National Soil Carbon Network: Concept, organization, and participation. Chris Swanston, USDA Forest Service, cswanston@fs.fed.us (Presenting) John Baker, USDA Agricultural Research Station, john.baker@ars.usda.gov Richard Birdsey, USDA Forest Service, rbirdsey@fs.fed.us Ronald Follet, USDA Agricultural Research Service, ronald.follett@ars.usda.gov Jennifer Harden, US Geological Survey, jharden@usgs.gov Julie Jastrow, Argonne National Laboratory, jdjastrow@anl.gov Mark Johnson, Environmental Protection Agency, johnson.markg@epa.gov

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Johannes Lehmann, Cornell University, cl273@cornell.edu Randy Kolka, USDA Forest Service, rkolka@fs.fed.us Robert Mckane, Environmental Protection Agency, mckane.bob@epa.gov William Parton, Colorado State University, billp@nrel.colostate.edu Wilfred Post, Oak Ridge National Laboratory, wmp@ornl.gov Peter Thornton, Oak Ridge National Laboratory, thorntonpe@ornl.gov Margaret Torn, Lawrence Berkeley Laboratory, mstorn@lbl.gov Sue Trumbore, University of California, Irvine, setrumbo@uci.edu Eric Vance, National Council for Air and Stream Improvement, evance@ncasi.org Mark Waldrop, US Geological Survey, mwaldrop@usgs.gov Larry West, USDA Natural Resources Conservation Service, larry.west@lin.usda.gov We are working to establish a national soil carbon network to provide spatially explicit assessments and prediction of soil carbon turnover and vulnerability in the US. The global stock of soil carbon is immense and dynamic: about 120 Pg of carbon moves annually between soil, atmosphere, and vegetation. Soil carbon may thus play a singular but uncertain role in climate forcing during the coming decades, with significant net losses contributing to positive feedbacks, or significant sequestration helping to mitigate climate forcing. The loss of soil carbon or disruption of its cycling may also impair the ecosystem services it provides, with consequent negative impacts on society. Given the critical role that soil carbon plays in the climate cycle and ecosystems services globally, there is a strong need to conduct large scale, spatially explicit assessments of soil carbon turnover and vulnerability. Recent advances in measurement technologies, statistical applications, modeling approaches, and geographic information systems have made it possible to develop stand-to-landscape scale information in support of carbon sequestration decisions by both land managers and policy makers. This network is a response by scientists to the urgent need for better understanding of the soil resource, and reflects a particular desire for greater integration of research and data across institutional boundaries. We have developed broad principles of organization and are actively seeking participation and input from the wider community. Keywords: Decision Support 102: Evaluating Forest Disturbance for the North American Carbon Program: Ongoing Research in the North American Forest Dynamics (NAFD) Study

102: Evaluating Forest Disturbance for the North American Carbon Program: Ongoing Research in the North American Forest Dynamics (NAFD) Study Nancy E. Thomas, University of Maryland, nthomas1@umd.edu (Presenting) Samuel N. Goward, University of Maryland, sgoward@umd.edu Jeffrey G. Masek, Biospheric Sciences Branch, NASA GSFC, jeffrey.g.masek@nasa.gov Warren B. Cohen, USDA Forest Service, warren.cohen@oregonstate.edu Gretchen G. Moisen, USFS Rocky Mountain Research Station, gmoisen@fs.fed.us Chengquan Huang, University of Maryland, cqhuang@geog.umd.edu Sean Healey, USFS Rocky Mountain Research Station, sean.healey@oregonstate.edu Robert Kennedy, USDA Forest Service, robert.kennedy@oregonstate.edu Scott Powell, USDA Forest Service, scott.powell@oregonstate.edu Karen Schleeweis, University of Maryland, ska1@umd.edu Khaldoun Rishmawi, University of Maryland, rishmawi@umd.edu Adrienne Hinds, University of Maryland, ahinds2@umd.edu The North American Forest Dynamics (NAFD) study supports fundamental North American Carbon Program science goals by improving understanding of forest dynamics within North America to reduce uncertainties in carbon flux estimates. Through the NAFD project we are evaluating forest disturbance and regrowth patterns by combining U.S. Forest Service Forest Inventory and Analysis (FIA) field observations with biennial time series Landsat imagery. Phase I of the NAFD study examined forest dynamics and disturbance history from Landsat time series stacks (LTSS) for 23 sample locations within the United States. FIA field plot data were used to validate the changes mapped in the Landsat time series data by the vegetation change tracker (VCT) algorithm. Additional accuracy assessment was performed on selected sample LTSS using visual analysis of the time series compared with high resolution imagery. Results of NAFD disturbance mapping to date reveal generally high rates of forest disturbance across the U.S., with these rates varying both spatially and temporally. Ongoing work for the Phase II NAFD study expands on this initial work, in several ways, to meet NACP goals. We are adding additional sample locations in the conterminous U.S. to reduce error in nationwide estimates of disturbance. We are also now partnering with Canada and Mexico to improve our understanding of continent-wide forest dynamics. In addition, we are currently developing nationwide maps of disturbance rates from model-based estimators combined with the sample site locations to better meet the needs of carbon modelers. The NAFD project is also extending forest dynamics analyses by examining regrowth patterns. We are doing so by converting Landsat data stacks to biomass to better characterize the carbon significance of forest disturbance and regrowth. We are also employing radiative transfer modeling as a means to validate relationships between the FIA and Landsat measurements by employing the FIA field data to parameterize the RT model and compare with the actual Landsat observations. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 103: Exploring mechanisms that affect carbon storage in forest soils: Simulations from the PnET-SOM model

103: Exploring mechanisms that affect carbon storage in forest soils: Simulations from the PnET-SOM model Christina Tonitto, Cornell University, ct244@cornell.edu (Presenting) Christine L. Goodale, Cornell University, clg33@cornell.edu Scott V. Ollinger, University of New Hampshire, scott.ollinger@unh.edu Julian P. Jenkins, University of New Hampshire, julian.jenkins@unh.edu Anthropogenic forcing of the C and N cycles has caused rapid change in atmospheric CO2 and N deposition, with complex and uncertain effects on forest C and N balance. With some exceptions, models of forest ecosystem response to anthropogenic perturbation have historically focused more on aboveground than belowground processes; the complexity of soil organic matter (SOM) is often represented with abstract or incomplete SOM pools, and remains difficult to quantify. We developed a model of SOM dynamics in northern hardwood forests with explicit feedbacks between C and N cycles. The soil model is linked to the aboveground dynamics of the PnET model to form PnET-SOM. The SOM model includes: 1) physically measurable SOM pools, including humic and mineral-associated SOM in O, A, and B soil horizons, 2) empirical

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soil turnover times based on 14C data, 3) alternative SOM decomposition algorithms with and without explicit microbial processing, and 4) soluble element transport explicitly linked to the hydrologic cycle. We develop PnET-SOM as a tool for quantifying SOC storage in northeastern temperate forests. Our model simulations explore long-term SOC dynamics in response to soil N availability, litter quality, and litter quantity.

Keywords: Attribution, Prediction 104: Carbon consequences of forest disturbance and recovery across North America

104: Carbon consequences of forest disturbance and recovery across North America Christopher A Williams, Graduate School of Geography, Clark University, cwilliams@clarku.edu (Presenting) G James Collatz, NASA Goddard Space Flight Center, Hydrospheric and Biospheric Sciences Laboratory, jim.collatz@nasa.gov Jeffrey G Masek, NASA Goddard Space Flight Center, Hydrospheric and Biospheric Sciences Laboratory, jeffrey.g.masak@nasa.gov Forests of North American Terrestrial carbon are thought to be a significant long term sink for atmospheric carbon but are vulnerable to disturbances caused by fires, logging and pathogens. FIA data provides a valuable resource for estimating long-term forest sinks but the coarse spatial and temporal resolutions limit their use in atmospheric model approaches for understanding carbon sources and sinks. To overcome these limitations we parameterize a carbon cycle model using forest type, biomass, age, and productivity from FIA. We then apply disturbance recovery dynamics to maps of age since disturbance derived from analysis of biennial time series from 29 Landsat scenes across the conterminous U.S. for the period 1982-2005 (provided by the NAFD project, S. Goward PI). The resulting maps are spatially (~30 m) and temporally (~annual) explicit representations of biomass and carbon fluxes resulting from disturbance and regrowth for these representative regions. Extrapolating to the conterminous U.S. forests we show regrowth sink of ~0.22 PgC y-1 for the 2005 epoch, not accounting for emissions from biomass removals or local combustion. The largest regrowth sinks are found in the southeast, southcentral, and northwest, with spatially averaged net ecosystem productivity (NEP) of about 100 gC m-2 y-1. Despite low modern disturbance rates in the northeast and northern lakes states, the regrowth sink remains of moderate strength owing to the continued legacy of historical clearing. While broadly consistent with past findings, contemporary disturbance rates of 1 to 2 % per year tend to exceed rates inferred from the FIA <20-year age class, and thus slightly elevate the estimated forest regrowth sink. Keywords: Diagnosis, Attribution, Prediction, Regional/Continental Synthesis 105: Complexity, global climate change, and the factors controlling soil carbon cycling

105: Complexity, global climate change, and the factors controlling soil carbon cycling Devin Wixon, UW Madison, dwixon@gmail.com (Presenting) Teresa Balser, UW Madison, tcbalser@wisc.edu A proliferation of data being gathered to predict a critically important, urgent and social-policy related question leads to confusion, debate and divergent model results. This classic feature of complex systems is currently being evidenced in answering the question of a positive feedback response of soil respiration with increased temperatures due to global climate change. This research applies complex systems theory to examine the difficulty in answering the question. We follow the first four steps of soft systems modeling (SSM) to achieve a detailed analysis of the soft aspects of the question. The many confounding factors that can control temperature response are dependent on system state and scale, complicating the coherent synthesis of results. Supported by a literature review, we conclude that that varied perspectives on the system’s dynamics and its web of controlling factors have led to seemingly conflicting results for different system states. These factors are frequently referred to and depicted in the literature, but factor models are not equivalent and cannot be simply integrated. A comprehensive assessment of factors and their interactions across scales is lacking. A related conclusion is that nonequivalent models must be used to describe the system effectively, with the potential for robust predictions in areas of overlap. We use systems theory to construct a simplified hierarchy organizing the comprehensive universe of the factors that can potentially control soil microbial temperature response. Categories for factors include biotic (e.g. microbial community), abiotic (e.g. precipitation), and experimental (e.g. study duration) factors, with further levels separating criteria, indicators and metrics. This model is implemented as a relational database, including relationships between factors such as nesting and feedbacks. We conclude that although this model is limited to pairwise interactions, it provides a useful tool to assess potential interactions and factors of interest, and to quantify the system state. Keywords: Attribution, Prediction 106: Enhancing and Extending the North American Carbon Sink by Sustainable Wood Burial and Storage

106: Enhancing and Extending the North American Carbon Sink by Sustainable Wood Burial and Storage Ning Zeng, Univ Maryland, zeng@atmos.umd.edu (Presenting) Jay Gregg, Univ Maryland, gregg.jay@gmail.com Ben Zaitchik, NASA/GSFC, zaitchik@jhu.edu Brian Cook, Univ Maryland, bcook@atmos.umd.edu The North American carbon sink has played an important role in partially offsetting the accelerating fossil fuel CO2 release. This sink is largely due to forest regrowth from the abandonment of agricultural land, fire suppression and climate variability in the past century, as convincingly demonstrated in the SOCCR report. However, this carbon sink is expected to dwindle as these forests mature in the future. Here we discuss a method that has the potential to enhance and extend the lifetime of the US forest carbon sink. In this proposal, certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It is estimated that a sustainable long-term carbon sequestration potential for wood burial in the conterminous US is 0.8 GtC/y, corresponding to about 15% of the annual NPP. Burying wood can be most easily implemented for managed forests, forests recently damaged by natural disturbances such as hurricane and inset outbreaks, post-consumer wood, or where it also reduces fire danger. We will also discuss possible environmental impacts such as nutrient lock-up.

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Based on data from North American logging industry, the cost for wood burial is estimated to be $14/tCO2 ($50/tC), lower than the typical cost for power plant CO2 capture with geological storage. The low cost for carbon sequestration with wood burial is possible because the technique uses the natural process of photosynthesis to remove carbon from the atmosphere. The technique is low tech, distributed, safe, and can be stopped at any time, thus an attractive option for large-scale implementation in a world-wide or regional carbon market such as the Regional Greenhouse Gas Initiative. Keywords: Prediction, Decision Support, Regional/Continental Synthesis 107: Enhanced sources of atmospheric C from “stable” pools of soil organic C

107: Enhanced sources of atmospheric C from “stable” pools of soil organic C Sharon Alene Billings, University of Kansas, sharonb@ku.edu Susan E. Ziegler, Memorial University of Newfoundland, sziegler@esd.mun.ca (Presenting) Because of the large size of the terrestrial soil carbon (C) pool, even a small change in rates of soil organic C (SOC) formation vs. release could have large implications for global C budgets. It is particularly unclear how transformations of relatively labile vs. stable SOC will proceed with elevated CO2, which can result in increased belowground C inputs and reduced nitrogen (N) availability. To help address these issues, we synthesize results from recent elevated CO2 experiments at Duke FACE: 1) an exploration of SOC dynamics using application of 13C-labeled substrates (glucose and vanillin) to soils from these forested plots and 2) an assessment of future stability of “stable” SOC fractions using the 13CO2 tracer applied at this site via supplied CO2. We assessed how elevated CO2 and N availability influence microbial use and subsequent fates of these tracers. Laboratory incubations reveal an increased proportion of glucose- and vanillin-C usage by actinomycetes in the unfertilized, elevated CO2 soils. These same incubations reveal lower net incorporation of glucose-derived C into the largest size fractions over one year in elevated CO2 soils, regardless of N availability. The 13C-tracer applied in the field via supplemental CO2 further suggests increased activity of fungi and actinomycetes with elevated CO2 and increasingly restricted N availability; these organisms are adept at processing SOC pools considered relatively “stable.” Combined, these data suggest: 1) elevated CO2 can stimulate SOC turnover after labile inputs have become relatively stabilized such that net retention of those inputs declines; and 2) increasing N limitation accompanying elevated CO2 may induce greater turnover of the “stable” SOC typically accessed by fungi and actinomycetes. Thus, forests of the future may not only be less able to transform SOC inputs into stable pools, but may also increasingly experience release of extant stable pools of SOC as CO2. Keywords: Attribution, Prediction, Site-level Synthesis, Regional/Continental Synthesis

Decision Support Posters108: Landscape-scale Monitoring of the Forest Carbon Cycle

108: Landscape-scale Monitoring of the Forest Carbon Cycle Richard Birdsey, US Forest Service, rbirdsey@fs.fed.us (Presenting) Coeli Hoover, US Forest Service, choover@fs.fed.us Linda Heath, US Forest Service, lheath@fs.fed.us Kenneth J. Davis, Pennsylvania State University, davis@meteo.psu.edu John Bradford, US Forest Service, jbbradford@fs.fed.us David Hollinger, US Forest Service, dhollinger@fs.fed.us Michael Ryan, US Forest Service, mgryan@fs.fed.us Yude Pan, US Forest Service, ypan@fs.fed.us John Hom, US Forest Service, jhom@fs.fed.us Kenneth Clark, US Forest Service, kennethclark@fs.fed.us Diagnosing, predicting, and managing forest carbon fluxes at scales from site to continent are essential to understanding and changing human contributions to greenhouse gases. In-situ carbon cycle measurements, ranging from the precise temporal monitoring of a flux tower to a set of landscape-scale sampling plots, provide direct measurement of the effects of climate variability and discrete natural or human-induced events such as insect defoliation or timber harvest. These measurements are characterized as “tier 2” (landscape-scale carbon cycle measurements) in the NACP science implementation plan. Though there are many such observation studies and networks operating at any given moment, the collective effort is insufficient to represent the range of landscape conditions and is insecure with respect to continuity observations. Here we review the current sampling network of the North American in-situ observation system, the measurements taken and the major data gaps, and their contribution to answering the 4 major questions of the North American Carbon Program. In general, these measurements enable integration of flux tower observations with satellite data, help integrate across components of the forest carbon cycle, and provide a strong foundation for understanding what is observed. In applications, these measurements may be used as ground truth, for upscaling, for model parameters, and for benchmarking in decision-support systems. Keywords: Diagnosis, Attribution, Prediction, Decision Support 109: Soil carbon storage in the Southern Appalachians across a gradient of land use: forests, pastures, and Christmas tree farms

109: Soil carbon storage in the Southern Appalachians across a gradient of land use: forests, pastures, and Christmas tree farms Samantha Chapman, Villanova University, samantha.chapman@villanova.edu (Presenting) Adam Langley, Smithsonian Environmental Research Center, langleya@si.edu Soil carbon storage depends on land-use history. We investigated the carbon storage potential of forests, pastures and Christmas tree farms in the Southern Appalachian mountains as a model of land management impacts on soil carbon. We quantified soil carbon stocks in tree farms across a chronosequence of cultivation duration and among herbicide management regimes. We referenced soil carbon stocks in farms to those in adjacent pastures and native forests to account for variability in other soil-forming factors. We partitioned soil carbon into fractions delineated by stability, an important determinant of long-term sequestration potential. We measured NDVI and soil microclimate in tree

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farms, pastures and forests in order to assess variation across sites that might contribute to soil carbon differences. Preliminarily, we have seen that soil carbon stocks in the intermediate pool are significantly greater in the tree farms under cultivation for longer periods of time than in the younger tree farms. This pool can be quite large, yet has the ability to respond to biological environmental changes on the centennial time scale. Also, soil carbon in pastures was significantly greater than both forest and tree farm soil carbon, which were not different from each other. These data can help inform land management and soil carbon sequestration strategies. Keywords: Diagnosis, Attribution, Decision Support, Site-level Synthesis 110: The transition to cellulosic biofuels under three levels of NPP

110: The transition to cellulosic biofuels under three levels of NPP Francis J Pierce, Washington State University, fjpierce@wsu.edu Harold P Collins, USDA-ARS, Prosser, WA, hal.collins@ars.usda.gov (Presenting) Daniel S Long, USDA-ARS, Pendleton, OR, dan.long@ars.usda.gov Stephan L Albrecht, USDA-ARS, Pendleton, OR, stephan.albrecht@oregonstate.edu Stephen J Fransen, Washington State University, fransen@wsu.edu Eileen M Perry, Washington State University, eileen_perry@wsu.edu Stephen L Young, Washington State University, steve_young@wsu.edu The production and removal of biomass for energy production will significantly change the agricultural landscape in the United States and will likely occur in a short time span. The implications for below ground soil processes are considerable since the removal of crop residues, a change to biomass energy crop production, and an increase in the use of marginal lands will all impact C and nutrient budgets over large areas of the US. This research provides a quantitative assessment of soil C and nutrient dynamics during the transition to cellulosic bioenergy cropping systems in response to crop residue removal and herbaceous biomass production over a range of net primary productivity (NPP). Within different NPP levels, we are evaluating how soil C and N cycles respond to corn, mustard, and/or wheat production with and without residue removal compared with dedicated biomass energy crop production using a monoculture and a polyculture. This project was initiated in the summer of 2007 with the installation of field experiments in Prosser, WA, and Pendleton, OR. The experimental treatments consist of crop type, biomass removal, and NPP level created using irrigation with corresponding fertilizer management in the low rainfall zones of the Columbia Basin. Crops include continuous corn (Zea mays L.), continuous wheat (Triticum aestivum L.), mustard (Brassica rapa L.), and two biomass energy crops, a monoculture of switchgrass (Panicum virgatum L.), and a polyculture mix consisting of switchgrass, eastern gammagrass (Tripsacum dactyloides), big bluestem (Andropogon gerardii), and Illinois Bundleflower (Desmanthus illinoensis). The 2008 growing season is the first year of this study and we have only recently completed harvest. Crop yield and biomass production will be discussed relative to changes in soil C observed as affected by NPP during the first transitional year of the shift to bioenergy crop production. Keywords: Diagnosis, Site-level Synthesis 111: Mapping Soil Organic Carbon in the U.S. Corn Belt

111: Mapping Soil Organic Carbon in the U.S. Corn Belt Paul Doraiswamy, U.S. Department of Agriculture, Agricultural Research Service, paul.doraiswamy@ars.usda.gov (Presenting) Hector Causarano, U.S. Department of Agriculture, Agricultural Research Service, hector.causarano@ars.usda.gov Cesar Izaurralde, Pacific Northwest National Laboratory and University of Maryland, cesar.izaurralde@pnl.gov Craig Daughtry, U.S. Department of Agriculture, Agricultural Research Service, craig.daughtry@ars.usda.gov Jerry L. Hatfield, U.S. Department of Agriculture, Agricultural Research Service, jerry.hafield@ars.usda.gov Soil carbon sequestration in the U.S. Con Belt was studied to evaluate the impact of land-use, soil and crop management that can play a significant role in promoting the mitigation of atmospheric CO2 and improve soil quality such as reduced erosion and also increase soil organic carbon (SOC) content. The objective of this research was to study the rate of soil carbon sequestration across the study region to understand the potential sinks and recommend soil and crop management practices to enhance or maintain soil carbon sequestration rates. The Environmental Policy Integrated Climate (EPIC) model was adapted to study the long term impact of soil and crop management practices on soil carbon sequestration in the U.S. Corn Belt. Landcover classification from Landsat imagery was use to develop the baseline soil carbon and to project the potential future trends in soil carbon sequestration rates. A detailed and computationally intensive approach integrating the EPIC model with soil, climate, land use, and management data was developed to conduct simulations at a grid-cell level of 2.59 km2. Based on the soils data, current SOC stocks are estimated to be 11 - 157 Mg C ha-1 in the top 20 cms across the study region. Uncertainties were 26 - 30% when simulations were conducted at the regional scale but reduced to 8 - 11% with site-specific simulations. The suggested potential enchantments in the rates of soil carbon sequestration are based on adaptation of long-term prescribed tillage practices, residue management, clay content, slope and elevation. A web-based decision support system was developed for end-users at the farm and regional scales to optimize management practices to maximize the potential increase in SOC and maintain crop production. Keywords: Decision Support, Site-level Synthesis, Regional/Continental Synthesis 112: An update of the organic carbon found in soils of Mexico

112: An update of the organic carbon found in soils of Mexico J. D. Etchevers, Colegio de Postgraduados, jetchev@colpos.mx (Presenting) C. O. Cruz, INEGI, carloscruzg@yahoo.com.mx C. Balbontin, Colegio de Postgraduados, cbalbontin@colpos.mx F. Paz, Colegio de Postgraduados, pellat@colpos.mx B. de Jong, Colegio d ela Frontera Sur, bjong@ecosur.mx Preliminary data on soil contribution to the Mexico’s total CO2 emissions from the LULUCF sector for the period 1993-2002 (86877 Gg y-1CO2), shows that soils were responsible for 34 % (33750 Gg y-1CO2 ) (3rd National Inventory of GHG). This figure places soils as the third CO2 emitter after biomass loss and emissions from the energy sector. Soil organic carbon (SOC) can contribute to mitigate increasing atmospheric CO2 by designing restoration programs applied to marginal land, to restoration of degraded land, faster adoption of minimum tillage programs, and other soil conservation practices. The emission data were estimated with a database of approximately 4000 soil samples. A more detailed study is underway. An additional 23010 soil profiles obtained by INEGI representing all physiographic regions of the

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country, collected during the last 39 years are available now. Preliminary analysis of the database indicate that the highest SOC are found in the eutric Histosols of the Southern Gulf part and the coastal plains of the Pacific (13.9% SOC) , the mollic Solochaks and Gleysols of the Yucatan Peninsula (12.6 % SOC) and the humic Andosol of Mexico’s Transvolcanic Belt (5.3 % SOC). The lowest SOC values were found in the Sonora Desert and Baja California soils, and in Yermosols of Durango and Coahuila. One problem with the current database is the high uncertainty related to bulk density values. A national sampling strategy is underway to solve this problem. The information currently available will serve as a base line to start long-term studies on the dynamics of SOC under various land-use systems that will eventually improve significantly our estimations of soil related CO2 emissions from land use and land use change. Keywords: Decision Support, Regional/Continental Synthesis 113: Selective Stabilization of Root and Leaf-Derived Lignin and Aliphatic Biopolymers among Soil Organic Matter Fractions: Comparison of Ambient and Elevated Atmospheric CO2 Rings in the Sweetgum Free Air CO2 Enrichment (FACE) Experiment.

113: Selective Stabilization of Root and Leaf-Derived Lignin and Aliphatic Biopolymers among Soil Organic Matter Fractions: Comparison of Ambient and Elevated Atmospheric CO2 Rings in the Sweetgum Free Air CO2 Enrichment (FACE) Experiment. Timothy R. Filley, Department of Earth and Atmospheric Sciences and the Purdue Climate Change Research Center, Purdue University, filley@purdue.edu (Presenting) Julie D. Jastrow, Biosciences Division, Argonne National Laboratory, jdjastrow@anl.gov Sarah L. O'Brien, Department of Biological Sciences, University of Illinois, Chicago, moran@anl.gov Kelly K. Moran, Biosciences Division, Argonne National Laboratory, moran@anl.gov Thomas W. Boutton, Department of Ecosystem Science & Management, Texas A&M University, boutton@acs.tamu.edu Responses of soil organic matter pools to elevated CO2 must be characterized in order to accurately predict/model the carbon cycle at ecosystem and global scales. Here we address mechanisms responsible for increased belowground C storage at the sweetgum FACE experiment at Oak Ridge National Laboratory. Plant C fixed under ambient and elevated CO2 was traced into microaggregated and non-microaggregated particulate organic matter (POM), silt, and clay using alkaline CuO-extractable biopolymers (i.e. lignin phenols and aliphatic biopolymer substituted fatty acids-SFA). Sweetgum leaf litter and roots exhibited distinct concentrations of octadecyl and hexadecyl-substituted fatty acids allowing us to track their relative contributions to SOM. Soils from all rings, both ambient and elevated, showed consistent relationships among fractions in that lignin phenols were elevated in microaggregated POM as well as fine and coarse non-microaggregated POM with the lowest contents associated with microaggregated clays. Ratios of SFA indicated that root-derived tissue was quantitatively more important for non-microaggregated POM while foliar tissue is selectively accrued in microaggregates and microaggregated POM. Over the course of 5 y large difference in the nature and quantity of lignin and SFA among the fractions developed in the experiments. In the ambient rings most fractions showed a trend to selective enrichment of lignin to SFA while this was only true for microaggregated POM in the elevated rings. In all rings silts and clays showed progressive shifts to foliar aliphatic input while microaggregated POM exhibited shifts to root derived material. The latter shift was particularly striking in the elevated CO2 rings. These results illustrate the dynamic nature of carbon accrual and the potential role of root and leaf tissue in selective stabilization. Keywords: Attribution, Prediction, Decision Support, Site-level Synthesis 114: A method for measuring and monitoring carbon stores in the above and belowground compartments of two vegetation types of the tropical subhumid regions of Mexico

114: A method for measuring and monitoring carbon stores in the above and belowground compartments of two vegetation types of the tropical subhumid regions of Mexico Jesus David Gomez, Universidad Autonoma Chapingo, dgomez@correo.chapingo.mx (Presenting) Jorge Dionicio Etchevers, Colegio de Postgraduados, jetchev@colpos.mx Julio Campo, Universidad Nacional Autonoma de Mexico, jcampo@ecologia.unam.mx Alejandro Ismael Monterroso, Universidad Autonoma Chapingo, aimrivas@correo.chapingo.mx A methodology was established to measure C stores in the above and belowground fractions of two main types of vegetation, one from dry deciduous tropical forest and another from an oak forest, both of three different ages, approximately 10, 20 and 40 years, in the “Sierra de Huautla” Biosphere Reserve, Morelos, Mexico. C in the aerial part of the system was estimated from the dry weight of the components. The biomass of woody plants with diameters at breast height (DBH) >2.5 cm was estimated using alometric equations generated specifically for this purpose for the species with higher importance index in three 1000 m2 plots for each sampling condition. Dry weight of the litter and humus components was measured by sampling directly over the entire plot, at twelve sites measuring 1.0 m2. C accumulated in the underground fraction (soil and roots) was measured in soil samples at 15 cm increases in depth up to 90 cm, or up to the depth the soil structure permitted. Measured in these samples were fine roots, bulk density and total C associated with soil mineral. Thick roots (>0.5 cm) were measured in a pit located at the center of the plot, with dimensions of 2.0 m2. Roots were collected at intervals of 15 cm to estimate their dry weight and the C associated with them. The highest quantity of total C was found in the oak forest, and within this, the highest was in the 40 year-old vegetation (147.6 Mg ha-1 C); the lowest quantity was in conditions of the dry deciduous tropical forest with the lowest value for the age of 10 years (11.3 Mg ha-1). In all of the oak forest cases, the largest volume of C was found in the arborous stratum and, for the conditions of dry deciduous tropical forest, in the soil. Keywords: Decision Support, Site-level Synthesis 115: Rapid Assessment and Modeling of Soil Carbon Pools across Florida

115: Rapid Assessment and Modeling of Soil Carbon Pools across Florida Sabine Grunwald, University of Florida, sabgru@ufl.edu (Presenting) Brenton D. Myers, University of Florida, myersdb@ufl.edu Willie G. Harris, University of Florida, apatite@ufl.edu Nicholas B. Comerford, University of Florida, nbc@ufl.edu Gregory L. Bruland, University of Hawai’i Mānoa, bruland@hawaii.edu It has been estimated that the total global soil carbon pool is four times the biotic pool and about three times the atmospheric pool. Hence, even relatively small changes in soil carbon storage per unit area could have a significant impact on the global carbon balance. The soils carbon reservoir is complex due to many overlapping ecosystem processes that continually reshape labile, recalcitrant and total carbon pools

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in space and time. Land use/land cover and climate change have been suggested to modulate carbon pools. These shifts are prominent in Florida and may impact soil carbon sequestration and attainable soil carbon stocks in the future. Our project objectives are to: (i) Determine soil carbon pools in various ecosystem types across a large southeastern landscape (Florida) cutting across soil nutrient, LC/LU and climatic/hydrologic gradients; (ii) Investigate the strength and magnitude of relationships between environmental landscape properties and corresponding carbon pools within a GIS; (iii) Derive functional models relating measured soil carbon fractions to soil spectra in the visible/near-infrared (VNIR) range to develop rapid and cost-effective soil carbon prediction models; (iv) Model change trajectories, i.e. assess historic and actual soil carbon stocks and turnover rates in various ecotypes; and (v) Upscale site-specific VNIR-derived and laboratory-measured soil carbon pools to the landscape scale by modeling spatial autocorrelations and covariations with environmental landscape properties; and validate the derived geospatial soil carbon models using an independent dataset. We present results from a subset region in north-eastern Florida (~3,500 km2) for which spectral carbon prediction models were developed for SOC with R2 of 0.86, and various carbon fractions and carbon mineralization rate using partial least squares regression and boosted regression trees. Geospatial soil carbon distribution patterns were derived using hybrid geostatistical methods combining SOC, carbon fractions and environmental covariates. The total soil organic carbon ranges from less than 0.5 to 61 kg m-2. A total of 16.513, 6.576, 7.498 and 4.549 million metric tons of carbon are stored in 0-30, 30-60, 60-120 and 120-180 cm soil depth, respectively. Land use/land cover change effects were modeled using back and forecasting techniques Keywords: Attribution, Decision Support, Regional/Continental Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 116: Synthesis of Forest Carbon Dynamics at the Landscape Level

116: Synthesis of Forest Carbon Dynamics at the Landscape Level Sean P. Healey, US Forest Service (Forest Inventory and Analysis), seanhealey@fs.fed.us (Presenting) Todd Morgan, University of Montana, Bureau of Business and Economic Research, todd.morgan@business.umt.edu Shawn Urbanski, US Forest Service, (Fires, Fuels, Smoke Program; Rocky Mountain Research Station), surbanski@fs.fed.us Loeffler Dan, US Forest Service, drloeffler@fs.fed.us Greg Jones, US Forest Service (Human Dimensions Program; Rocky Mountain Research Station), jgjones@fs.fed.us Blackard Jock, US Forest Service (Forest Inventory and Analysis), jblackard@fs.fed.us Moisen Gretchen, US Forest Service (Forest Inventory and Analysis), gmoisen@fs.fed.us DeBlander Larry, US Forest Service (Forest Inventory and Analysis), ldeblander@fs.fed.us Frescino Tracey, US Forest Service (Forest Inventory and Analysis), tfrescino@fs.fed.us The carbon dynamics of forest ecosystems in the United States have been estimated and modeled at both national and regional levels. However, the monitoring of more local landscapes in policy- and management-relevant ways has been limited by the complexity, local variation, and interaction of the processes involved. Relevant processes include: tree growth, disturbance, and forest product utilization. We have developed a system by which a number of nationally available monitoring resources are brought to bear in a specific landscape to track and harmonize different components of the carbon cycle. Specifically, we use Landsat image time series via the North American Forest Dynamics project, forest inventory data from the Forest Service’s Forest Inventory and Analysis unit, carbon pool heuristics also developed by the Forest Service, a spatially explicit fire effects model, regional timber utilization data, and Timber Product Output data that tracks timber harvesting at the mill level. This system, which is being piloted in Ravalli County, Montana, creates the ability to track the intake of carbon on the landscape through growth, the release of carbon through disturbance and decay, and the temporary sequestration of carbon in forest products. Because the system is spatially explicit, with known locations of harvests and mill destinations, this system can also track fossil carbon emissions related to timber harvest and transport. In addition to creating a monitoring system sensitive to variation in harvest and fire patterns, integration of this type should provide insight into the relative importance of these and other factors in driving a landscape’s overall carbon balance. Further, because this system reflects processes specific to a particular landscape, it will in the future provide opportunities to simulate alternative management and climate scenarios. Keywords: Decision Support, Site-level Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 117: Carbon Consequences of Thinning: Initial Results from Long-Term Studies on Experimental Forests

117: Carbon Consequences of Thinning: Initial Results from Long-Term Studies on Experimental Forests Coeli M Hoover, US Forest Service, Northern Research Station, choover@fs.fed.us (Presenting) The increased interest in forest carbon sequestration and management leads to a need for reliable estimates of standing forest carbon stocks, knowledge about the rate of change of those stocks, and a set of management guidelines designed to preserve and enhance the forest carbon storage. The Forest Service has a rich legacy of long-term silvicultural experiments on which we can draw to begin to understand the impacts of various management practices and other factors on forest carbon storage. This poster uses data from a number of long-term studies in various forest types across the US to assess the carbon consequences of thinning treatments on carbon stocks and changes in those stocks. These long-term studies, begun in the past, can lead us toward management guidelines to enhance forest carbon sequestration in the future. It is unlikely that a 'one size fits all' strategy will emerge; carbon storage is one management objective among many, and factors such as forest type, site history, age structure, and short-term vs. long-term goals need to be considered. Analysis of long-term research records will begin to point out the critical variables in carbon management that can be integrated into a decision support framework. Keywords: Decision Support, Site-level Synthesis 118: The National Biomass and Carbon Dataset 2000: A high-resolution baseline of conterminous U.S. Biomass and Carbon Stocks from InSAR/Optical Fusion

118: The National Biomass and Carbon Dataset 2000: A high-resolution baseline of conterminous U.S. Biomass and Carbon Stocks from InSAR/Optical Fusion Josef Kellndorfer, Woods Hole Research Center, josefk@whrc.org (Presenting) Wayne Walker, Woods Hole Research Center, wwalker@whrc.org Katie Kirsch, Woods Hole Research Center, kkirsch@whrc.org Greg Fiske, Woods Hole Research Center, gfiske@whrc.org

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Elizabeth LaPoint, USDA-Forest Service Forest Inventory and Analysis (FIA), elapoint@fs.fed.us Mike Hoppus, USDA-Forest Service Forest Inventory and Analysis (FIA), mhoppus@fs.fed.us James Westfall, USDA-Forest Service Forest Inventory and Analysis (FIA), jameswestfall@fs.fed.us One of the goals of the North American Carbon Program (NACP) is to develop a quantitative scientific basis for regional- to continental-scale carbon accounting to reduce uncertainties about the carbon cycle component of the climate system. In support of this goal, the National Biomass and Carbon Dataset 2000 (NBCD 2000), a high-resolution, ecoregional database of circa-2000 vegetation canopy height, above ground biomass, and carbon stocks for the conterminous U.S., has been completed. Area-based estimates of terrestrial biomass and carbon are best captured when biophysical measures of both horizontal and vertical vegetation structure are obtained. Given the complementary nature and quasi-synchronous data acquisition of the InSAR 2000 Shuttle Radar Topography Mission (SRTM), the Landsat-based 2001 National Land Cover Database (NLCD), and data sets from the national LANDFIRE project, this project exploits the synergy afforded by the fusion of these high-resolution, spatially explicit data sources. Whereas the thematic layers of the NLCD and LANDFIRE projects were suitable for characterizing horizontal structure (i.e., cover type, canopy density, etc.), the SRTM acquisition, in conjunction with the National Elevation Dataset (NED), provided information relating to the vertical structure, i.e., primarily height. To produce maps of canopy height and aboveground biomass from these remotely sensed data sources, field reference data obtained from the USDA Forest Service - Forest Inventory and Analysis (FIA) network of sample plots were used to develop tree-based regression models for use in height and biomass predictions. The NBCD 2000 project followed the same ecoregional mapping zone approach employed by the NLCD and LANDFIRE projects. For each of the 66 ecoregional mapping zones comprising the conterminous U.S., high-resolution (30 m) raster maps of canopy height and aboveground biomass together with error estimates are now available online (http://whrc.org/NBCD). Keywords: Diagnosis, Prediction, Decision Support, Software Tools, Instruments, Data Management, Programmatic Topics 119: Is Iowa Currently a Carbon Sink? GEMS Simulated Changes in Ecosystem Carbon Stocks and Fluxes from 1972 to 2007

119: Is Iowa Currently a Carbon Sink? GEMS Simulated Changes in Ecosystem Carbon Stocks and Fluxes from 1972 to 2007 Shuguang Liu Liu, USGS EROS Center, sliu@usgs.gov (Presenting) Zhengxi Tan, ARTS, contractor to USGS EROS Center, ztan@usgs.gov Zhengpeng Li, ARTS, contractor to USGS EROS Center, zli@usgs.gov Shuqing Zhao, ARTS, contractor to USGS EROS Center, szhao@usgs.gov Wenping Yuan, US National Research Council (NRC) Postdoctoral Fellow, wyuan@usgs.gov Upscaling the spatial and temporal changes of carbon stocks and fluxes from sites to regions is a critical and challenging step toward improved understanding and quantifying the dynamics of carbon sources and sinks over large areas. This study, as part of the North American Carbon Program (NACP) Mid-Continent Intensive Campaign (MCI) Interim Synthesis of Regional CO2 Fluxes, simulated carbon dynamics in Iowa from 1972 to 2007 using the General Ensemble Biogeochemical Modeling System (GEMS). GEMS is capable of spatially simulating the impacts of agricultural practices (e.g., conservation practices, irrigation, fertilization, drainage, crop rotation, and genetics) over large areas. It simulates soil organic carbon dynamics in the entire soil profile rather than just in the top soil layer. GEMS can produce uncertainty estimates through ensemble simulations which transfer uncertainty from inputs to outputs. GEMS successfully captured the spatial and temporal variability of historical grain yield in Iowa. Results indicated that Iowa soil has been a carbon source since 1972. This was largely caused by the installation of a massive drainage system in the region which led to the release of soil carbon in deep soil layers that was previously protected by poor drainage conditions. Management practices (e.g., conservation practices) have slowed down the total release of carbon from the soils but could not reverse the general trend of net soil carbon release in the region. At the ecosystem level, Iowa has been a large atmospheric carbon sink. However, this sink did not lead to long-term carbon sequestration in soil and vegetation. Most of the carbon absorbed by terrestrial ecosystems has been harvested as stalk and grain and subsequently transported to other places. Keywords: Diagnosis, Attribution, Decision Support, Regional/Continental Synthesis, MCI Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 120: The Legacy of Invasive Species on Ecosystem Carbon Dynamics in a Restored Tallgrass Prairie

120: The Legacy of Invasive Species on Ecosystem Carbon Dynamics in a Restored Tallgrass Prairie Roser Matamala, ANL, matamala@anl.gov (Presenting) Scott Graham, UIC, sgraha3@uic.edu David R Cook, ANL, drcook@anl.gov Miquel A Gonzalez-Meler, UIC, mmeler@uic.edu Michael Ritchie, ANL, mtritsche@anl.gov Restoration of degraded grassland and prairie ecosystems represents a target sink for offsetting rising atmospheric CO2 levels by increasing carbon sequestration in C-depleted soils, as two-thirds of the biomass is allocated belowground. When considering controls on ecosystem C cycling, biodiversity-led productivity has the potential to be a strong biotic influence. However, invasive species can disrupt ecosystem processes by exhibiting functional characteristics which are distinct from their native counterparts. Invasibility has been linked to disturbance history, which might lead to additional vulnerability of managed lands. The restoration of tallgrass prairie at Fermilab, Batavia, IL, is a known C sink, accruing soil organic matter at rates 43 g C m-2 s-1 during the past 20 years. This rate integrates environmental, climatic and vegetation variations that occurred over this period. Typically, the tallgrass prairie is dominated by warm season grasses and forbs with sporadic but recurrent years when invasive species increase productivity. We measured net ecosystem exchange, net ecosystem production (NEP) and soil C at a 19-year-old restored tallgrass prairie in a four year study where plant species dominance varied. In the first year, the prairie restoration was a strong C sink with a NEP 438 g C m-2 despite a pronounced spring drought. During the second year, dominance of the invasive biannual Melilotus alba, led to a shorter growing season that resulted on a 47% reduction in NEP from the previous year. NEP did not recover in the third year, even when M. alba was present but not dominant and a number of prairie species re-emerged, showing the legacy of the previous year disturbance. At this time soil C for all years and a fourth NEP year is being analyzed. These data suggest that biotic factors can exert large memory effects on NEP and possibly influence the sink capacity of restored ecosystems. Management strategies should aim to control biotic limitations to NEP in order to maximize long term C sequestration of restorations. Keywords: Attribution, Prediction, Decision Support 121: Biotic and Abiotic Factors Controlling Soil Respiration Partitioning in a Tall Grass Prairie

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121: Biotic and Abiotic Factors Controlling Soil Respiration Partitioning in a Tall Grass Prairie Nuria Gomez-Casanovas, UIC, nuriagomezcas@hotmail.com Roser Matamala, ANL, matamala@anl.gov (Presenting) David R Cook, ANL, drcook@anl.gov Miquel A Gonzalez-Meler, UIC, mmeler@uic.edu Soil respiration is a major component of ecosystem respiration, and small changes in soil CO2 efflux can have a major impact on the amount of carbon released back to the atmosphere. Contributions to soil respiration come both from free-living soil microorganisms decomposing soil organic matter (heterotrophic respiration) and from roots and rhizosphere microorganisms (autotrophic respiration). Little is known about the factors underlying the partitioning of soil respiration into auto- and heterotrophic components, although increasing evidence shows that these components respond differently to vegetation, climate and environmental factors. Improving our understanding about factors controlling the partitioning of soil respiration is a major concern to predicting ecosystem respiration in global change scenarios. We investigated biotic and abiotic factors that affect auto- and heterotrophic respiration in a 19-year-old restored tall grass prairie at Fermi National Accelerator Laboratory in Batavia, IL. Four automated soil respiration chambers continuously measured soil CO2 efflux during the growing season. Total soil respiration was separated into its heterotrophic and autotrophic components by using a stable-isotope mass balance technique based on the differential 13C/12C ratio of the respired CO2 from roots and soil at the site. Keeling plot measurements and root and soil incubations were conducted every three weeks at midday and at night to detect temporal changes in the end members that affect mass balance calculations during the growing season. Continuous measurements were also made of soil moisture, soil temperature, and net ecosystem exchange derived from eddy correlation techniques. Preliminary results show that the proportion of autotrophic respiration to total respiration was larger during the earlier part of the growing season, while the proportion of heterotrophic respiration to total respiration increased later in the growing season. Our results suggest that differential controlling factors for soil respiration components might be operating differently in time. Keywords: Attribution, Prediction, Decision Support 122: Temporal Changes in C and N Stocks of Restored Prairie. Implications for C Sequestration Strategies

122: Temporal Changes in C and N Stocks of Restored Prairie. Implications for C Sequestration Strategies Roser Matamala, ANL, matamala@anl.gov (Presenting) Julie D Jastrow, ANL, jdjastrow@anl.gov Michael R Miller, ANL, rmmiller@anl.gov Charles Jr T Garten, ORNL, gartenctjr@ornl.gov The recovery of ecosystem C and N dynamics after disturbance can be a slow process. Chronosequence approaches offer unique opportunities to use space-for-time substitution to quantify the recovery of ecosystem C and N stocks and estimate the potential of restoration practices for C sequestration. We studied the distribution of C and N stocks in two chronosequences that included long-term-cultivated lands, 3 to 26 y old prairie restorations, and remnant prairie on two related soil series. Results from the two chronosequences did not vary significantly and were combined. Based on modeling predictions, the recovery rates of different ecosystem components varied greatly. Overall, C stocks recovered faster than N stocks, but both C and N stocks recovered more rapidly for aboveground vegetation than for any other ecosystem component. Aboveground C and N reached 95% of remnant levels in only 13 y and 21 y, respectively, after planting to native vegetation. Belowground plant C and N recovered several decades later, while microbial biomass C, soil organic C (SOC), and total soil N recovered on a century time scale. In the cultivated fields, SOC concentrations were depleted within the surface 25 cm, coinciding with the depth of plowing, but cultivation apparently led to redistribution of soil C, increasing SOC stocks deeper in the soil profile. The restoration of prairie vegetation was effective at rebuilding soil organic matter (SOM) in the surface soil. Accrual rates were maintained at 43 g C m-2 y-1 and 3 g N -2 y-1 in the surface 0.16 Mg m-2 soil weight during the first 26 y of restoration and were predicted to reach 50% of their storage potential (3500 g C m-2) in the first 100 y. We conclude that restoration of tallgrass prairie vegetation can restore SOM lost through cultivation and has the potential to sequester relatively large amounts of SOC over a sustained period of time. Whether restored prairies can retain the C apparently transferred to the subsoil by cultivation practices remains to be seen. Keywords: Prediction, Decision Support 123: Fuel loading and consumption models for assessing carbon release from wildland fires

123: Fuel loading and consumption models for assessing carbon release from wildland fires Don McKenzie, US Forest Service, dmck@u.washington.edu (Presenting) Roger D Ottmar, US Forest Service, rottmar@fs.fed.us Nancy French, Michigan Technological University, nancy.french@mtu.edu Total carbon released from wildland fires can be estimated from area burned, fuel loading, fuel consumption, and pollutant specific emission factors. Two factors alone -- fuel loading and fuel consumption -- account for up to 80 percent of the error associated with estimating total carbon. We show how ground-based estimates of these factors can be extrapolated to the continental scale by combining satellite-based vegetation layers with two software tools, the Fuel Characteristic Classification System (FCCS) and Consume 3.0. The FCCS quantifies fuelbed layers, including canopy, shrubs, nonwoody, woody, litter/lichen/moss, and duff, via an explicit linkage to vegetation types. FCCS fuelbeds represent the United States, including Alaska and Hawai’i, Canada, and a portion of Mexico. We present a fuelbed classification for the continental US (CONUS) at 1-km resolution, and show how this can be extended to cover North America. Fuel loadings are calculated from this classification and MODIS vegetation layers, including LAI (Leaf-Area Index) and VCF (Vegetation Continuous Fields). At each cell we calculate fuel consumption and emissions using Consume 3.0, which imports fuelbed data directly from the FCCS. We embed the models in a decision-support system to estimate both real-time consumption and carbon release from specific fire events and potential values given specific parameters for fire weather or fire intensity. Ground-based estimates of fuel loading and consumption complement and potentially validate remotely sensed estimates, thereby enhancing both real-time decision support and continental-scale modeling. Keywords: Decision Support, Regional/Continental Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 124: Storage and fluxes of carbon in the United States predicted from satellite data, ecosystem modeling, and inventory summaries: Synthesis and new focus on linkages to NASA’s Orbiting Carbon Observatory (OCO) Mission

124: Storage and fluxes of carbon in the United States predicted from satellite data, ecosystem modeling, and inventory

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summaries: Synthesis and new focus on linkages to NASA’s Orbiting Carbon Observatory (OCO) Mission Christopher Potter, NASA Ames Research Center, chris.potter@nasa.gov (Presenting) Steven Klooster, California State University, sklooster@gaia.arc.nasa.gov The NASA-CASA (Potter et al., 2007) plant and soil simulation model based on satellite observations of vegetation and climate data over the past decade has been used to estimate the fluxes of CO2 and carbon pools in biomass across all ecosystems of the conterminous United States. These modeled estimates of vegetative carbon potential in forests were compared to aggregated measurements of standing wood biomass from the U. S. Forest Service’s national Forest Inventory and Analysis (FIA) data set and the Carbon Online Estimator (COLE) to understand: 1) predominant geographic variations in tree growth rate and 2) local land cover and land use history including the time since the last stand-replacing disturbance (e.g., from wildfire or harvest). Net primary production in rangelands (and MCI croplands) was predicted across the country, with special attention to impacts of wildfires, shrubland and grassland carbon dynamics in the Interior West, and biofuel crop effects on land cover change and soil carbon pools. We also report on initial comparisons of spatially gridded data sets for both fossil fuel emissions and terrestrial ecosystem production fluxes of CO2 for the conterminous United States land surface. Hourly products from the Purdue University Vulcan Project were aggregated to monthly and annual anthropogenic source products. Comparison results indicate extensive carbon sink fluxes in ecosystem regions of the U. S. located far enough from most fossil fuel emission sources to provide well-isolated biosphere CO2 flux signals for future detection by the NASA OCO mission. Synthesis results from our ecosystem modeling coupled with satellite observations of the atmosphere, land cover, and green plant density will enable NACP synthesis to uniquely differentiate areas with a high potential for vegetative carbon storage at relatively fine spatial resolution. Potter, C., S. Klooster, A. Huete, and V. Genovese, 2007, Terrestrial carbon sinks for the United States predicted from MODIS satellite data and ecosystem modeling, Earth Interactions, 11: 1-21. Keywords: Diagnosis, Attribution, Decision Support, Site-level Synthesis, Regional/Continental Synthesis, MCI Synthesis, non-CO2 Greenhouse Gases Synthesis 125: Carbon Dynamics and Models on Land-use/cover Basis: Analysis from a Himalayan Watershed

125: Carbon Dynamics and Models on Land-use/cover Basis: Analysis from a Himalayan Watershed Purnima Sharma, 2478, NE Julep Street,Issaquah, WA-98029; USA, purnimas74@yahoo.com S C Rai, Department of Geography; Delhi School of Economics; University of Delhi, India, raisc1958@rediffmail.com (Presenting) Abstract Watershed is regarded as a functional unit for management in hills. Different land-use/covers are hydro-ecologically linked in watersheds. Carbon storage and flux are good indicators of productivity, soil fertility and sustainability of systems as well as of climate change. Mamlay watershed, having an elevational range of 300-2650 m with a total area of 3014 ha covering nine revenue blocks (34 villages) in Sikkim, was selected for this study. The main land-use/covers in the watershed are forests (50%), cash-crop based agroforestry (4%), cropped land (31%) and wasteland (15%). Agriculture has increased by more than 100% for the 13 years period, while wasteland increased by about 149% at the cost of forest cover. The total forest cover (temperate natural forest dense, temperate natural forest open and subtropical natural forest open) decreased by 28% during 1988 to 2001. Carbon storage and fluxes were estimated in different land-use/covers in the watershed. The forest conversion during the 13 years period resulted into large amounts of carbon release from vegetation and soil. The converted agriculture and wasteland showed rapid turnover and increased flux relative to stored carbon. The soil carbon levels drastically declined from forest to cropped area. The carbon loss through soil erosion was highest from cropped area and lowest from forest. A mathematical model for the circulation of carbon in the watershed ecosystem is developed on land-use basis to know the best land-use practices.

Keywords: Decision Support 126: Regional Environmental Impacts of Biofuel Feedstock Production—Scaling Biogeochemical Cycles in Space and Time

126: Regional Environmental Impacts of Biofuel Feedstock Production—Scaling Biogeochemical Cycles in Space and Time Andy David VanLoocke, University of Illinois, andyvanl@uiuc.edu (Presenting) Carl J Bernacchi, University of Illinois, bernacch@uiuc.edu Tracy E Twine, University of Minnesota, twine@umn.edu Recently there has been increasing socio-economic and scientific interest in the use of alternative sources of energy to offset the negative effects of current fossil fuel dependence and consequent greenhouse gas emissions. Currently, one of the most popular alternatives is to use ethanol produced from domestically grown crops for use as fuel in the transportation sector. In 2007, over 7.5 billion gallons of ethanol were produced in the U.S. from corn, a traditional food crop. Recent research indicates that it may be logistically impractical, ecologically counterproductive (i.e. a net carbon source), and economically devastating to produce ethanol from crops previously grown to produce food. The EBI (Energy Biosciences Institute, at University of California Berkley and University of Illinois Urbana-Champaign) is now conducting research to assess the ability of traditional crops as well as dedicated biofuel feedstocks (e.g. Panicum virgatum (switchgrass), Miscanthus x Giganteus (Miscanthus), and Saccharum spp (sugar cane)) to provide a productive and sustainable alternative to fossil fuel. This is an important step to take before implementing the large-scale growth necessary to meet U.S. energy needs .A process-based terrestrial ecosystem model, Agro-IBIS (Agricultural Integrated Biosphere Simulator) was adapted to simulate the growth of Miscanthus. The model was calibrated using data collected from sites at the University of Illinois south farms. Simulations indicated significant implications on the regional carbon and water budgets. Next this locally validated method will be extrapolated to simulate the regional scale growth of Miscanthus in the Midwestern U.S. and sugarcane in Brazil and a similar analysis will be conducted for switchgrass. The results should provide insight on optimal land-use decisions and legislation that regard meeting energy demands and mitigating climate change in the near future. Keywords: Diagnosis, Attribution, Decision Support, Site-level Synthesis, Regional/Continental Synthesis 127: Predicting Net Carbon Flux with Expected Changes in U.S. Agriculture: Some Potential Impacts of Bioenergy Crops in the U.S. Carbon Budget

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127: Predicting Net Carbon Flux with Expected Changes in U.S. Agriculture: Some Potential Impacts of Bioenergy Crops in the U.S. Carbon Budget Tristram O West, Oak Ridge National Laboratory, westto@ornl.gov (Presenting) Craig C Brandt, Oak Ridge National Laboratory, brandtcc@ornl.gov Chad M Hellwinckel, University of Tennessee, chellwin@utk.edu Robert D Perlack, Oak Ridge National Laboratory, perlackrd@ornl.gov Latha M Baskaran, Oak Ridge National Laboratory, baskaranl@ornl.gov Daniel G De La Torre Ugarte, University of Tennessee, danieltu@utk.edu Mark E Downing, Oak Ridge National Laboratory, downingme@ornl.gov Bradly S Wilson, University of Tennessee, driver8@utk.edu Richard G Nelson, Kansas State University, rnelson@ksu.edu Estimates of past and current net carbon flux (including net ecosystem exchange) are being developed using bottom-up approaches. Net carbon fluxes can be predicted for future years by integrating economic and land-use change modeling into bottom-up inventory approaches. Changes in cropland management associated with the adoption of carbon sequestration strategies bioenergy crop production are expected to be the predominant changes in US agriculture. We are estimating annual changes in net carbon flux from present to 2025, based on anticipated changes in crop production under the Energy Independence and Security Act of 2007. We will present changes in carbon flux and carbon inventories (e.g., soil, plant, and fossil emissions) associated with the use of grain, crop residues, and dedicated perennial feedstocks. These annual estimates will be presented for the entire nation at 1km resolution. Estimates presented here will contribute to core NACP research areas of prediction and decision support. Keywords: Prediction, Decision Support, MCI Synthesis 128: Impacts of Future Scenarios of Land Cover and Climate Change on Ecosystem Carbon Sequestration in the Southeastern United States

128: Impacts of Future Scenarios of Land Cover and Climate Change on Ecosystem Carbon Sequestration in the Southeastern United States Shuqing Zhao, ASRC Research and Technology Solutions, Contractor to U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, szhao@usgs.gov (Presenting) Shuguang Liu, USGS EROS, sliu@usgs.gov Zhengpeng Li, ASRC Research and Technology Solutions, Contractor to USGS EROS, zli@usgs.gov Terry Sohl, ASRC Research and Technology Solutions, Contractor to USGS EROS, sohl@usgs.gov There is a strong need for estimating biological carbon sequestration potential under various land use management and climate change scenarios to formulate strategies to mitigate global climate change. We used the General Ensemble biogeochemical Modeling System (GEMS) to simulate and compare ecosystem carbon dynamics for the southeastern United States from 1992 to 2050 under different future climate and land cover change scenarios. GEMS, which is capable of dynamically assimilating land use information into the simulation process across large spatial extents, was driven by unique combinations of spatial and temporal dynamics of major driving forces, such as climate, soil properties, nitrogen deposition, and land use and land cover changes. We used consistent, high-quality, and spatially explicit land cover change databases at 250- by 250-m resolution from 1992 to 2050 that were developed by the FOREcasting SCEnarios of future land cover (FORE-SCE) model. Based on this land cover dataset, we created two more scenarios with increased clearcutting because of forest aging and/or biofuel opportunities (a forest rotation of 25 years with a maximum initial clearcutting rate of 6% and a forest rotation of 25 years with a maximum initial clearcutting rate of 8%). We used three future climate scenarios that included business as usual, and low and high rates of greenhouse gas emissions. Our results indicated that carbon sequestration in the southeastern United States from 1992 to 2007 was about 1 Mg C ha-1 yr-1.The future carbon source/sink strength varied greatly, from a small sink to a strong source, depending on the path of land use changes. Climate variability and change had significant impacts on the interannual variability of carbon sinks and sources. Keywords: Prediction, Decision Support, Regional/Continental Synthesis

Site Synthesis Posters 129: A decadal study of soil carbon cycling on decadal time scales

129: A decadal study of soil carbon cycling on decadal time scales Eric A Davidson, The Woods Hole Research Center, edavidson@whrc.org (Presenting) Susan E Trumbore, University of California, Irvine, setrumbo@uci.edu Changes in soil carbon stocks are potentially an important biospheric feedback to climate change at decadal time scales. However, estimates of changes in soil C that cycles with mean residence times (MRTs) of several years to decades requires either confidence in model predictions or observations made over many years or both. The first objective of our study is to estimate the MRTs of soil C by remeasuring 14C fractions that were first measured more than a decade ago. Resampling of well-drained soils at the Harvard Forest in central Massachusetts shows a reduction in radiocarbon signature of O-horizon C and bulk soil C to depths of 20 cm from 1996 to 2007. This decline in radiocarbon contents is in general agreement with our projections based on a model constrained by 1996 measurements of soil fractionations and a carbon budget. A second objective is to estimate decadal trends in root and soil microbial respiration. On average, measured values of soil 14CO2 efflux fall along a line that is roughly parallel but elevated above the atmospheric 14CO2 line, indicating that the major sources of soil respiration include at least two components - one source that declines with the atmosphere (recently fixed C) and other sources that have 14C signatures 20-50 per mil higher than the atmosphere - i.e. with MRTs averaging decades. No change in the relative proportion of these sources has been detected during the last 12 years. A third objective is to estimate soil C pools susceptible to increased rates of decomposition in a soil warming experiment. No treatment effect on soil 14CO2 efflux has been detected after two years of warming, indicating no change in the mean age of total respired C. Taken together, these data permit quantification of the sizes and temperature sensivities of MRTs of soil C pools.

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Keywords: Attribution, Site-level Synthesis 130: Biometric and Eddy-Covariance Methods: Integrated Carbon Flux Analysis in a Mid-Latitude Deciduous Forest

130: Biometric and Eddy-Covariance Methods: Integrated Carbon Flux Analysis in a Mid-Latitude Deciduous Forest Danilo Dragoni, Indiana University, ddragoni@indiana.edu (Presenting) Craig A Wayson, Indiana University, cwayson@indiana.edu James C Randolph, Indiana University, randolph@indiana.edu Hans Peter Schmid, Institute of Meteorology and Climate Research - Germany, HaPe.Schmid@imk.fzk.de In this study, we compare eight years (1998-2005) of carbon budget estimates obtained by two independent methods: the micrometeorological approach based on eddy-covariance measurements, and the biometric method based on carbon stock increment measurements in a mixed deciduous forest in the Morgan-Monroe State Forest, Indiana, USA. Even though the cumulative estimates of both methods for the eight-year period are within 1% of each other, differences between biometric estimates of net ecosystem productivity (NEPBM) and the corresponding eddy covariance based estimates (NEPEC) were variable on annual basis (up to 27% in some cases). We focus our analysis on years with large differences between annual NEPEC and NEPBM estimates. We interpret our results in terms of inter-annual and seasonal meteorological variability (like late-spring or early-fall frost and intense and prolonged droughts) and consequences for allocation to different carbon pools. This work confirms the importance of using both approaches to reduce overall uncertainty of NEP estimates, increase the understanding of carbon partitioning among different compartments of the forest ecosystem, and helps to explain observed inter-annual variability. Keywords: Diagnosis, Attribution 131: Interannual Variation in Net Ecosystem Productivity of Canadian Forests as Affected by Regional Weather Patterns - a Fluxnet-Canada Synthesis

131: Interannual Variation in Net Ecosystem Productivity of Canadian Forests as Affected by Regional Weather Patterns - a Fluxnet-Canada Synthesis Robert F. Grant, University of Alberta, robert.grant@afhe.ualberta.ca (Presenting) Alan G. Barr, Meteorological Service of Canada, barr,alan [nhrc] alan.barr@ec.gc.ca T. Andrew Black, University of British Columbia, andy black andrew.black@ubc.ca Hank A. Margolis, Laval University, hank.margolis@sbf.ulaval.ca Allison L. Dunn, Worcester State College, allison.dunn@worcester.edu Shusen Wang, Canada Centre for Remote Sensing, shusen.wang@ccrs.nrcan.gc.ca Pierre Y. Bernier, Natural Resources Canada Canadian Forest Service, pbernier@rncan.gc.ca Large-scale weather patterns are known to cause substantial interannual variation in the net ecosystem productivity (NEP) of tropical, temperate and boreal forests. In earlier work, high air temperatures (Ta) during an El Niño event were shown to reduce annual NEP as derived from eddy covariance (EC) measurements over a Douglas fir stand in British Columbia. More persistent North Pacific SST anomalies, largely driven by PDO, ENSO and their interactions, have been associated with summer droughts that reduced forest productivity, particularly of deciduous stands, in Alberta, Saskatchewan and Manitoba. The lengthening instrumental record of CO2 exchange at EC flux towers along a transcontinental transect of forest stands in the Fluxnet-Canada Research Network (FCRN) now provides an opportunity to test model hypotheses for impacts on regional forest CO2 exchange of Ta and precipitation associated with large-scale weather patterns. We have built upon earlier FCRN modelling work by attributing interannual variability in NEP to changes in Ta and precipitation associated with large-scale weather events at all mature sites in the FCRN over the entire period of EC measurements to the end of 2006. Attribution is made through the ecosystem model ecosys, corroborated by eddy covariance measurements of CO2 and energy fluxes, wood growth increments from inventory studies, and from remotely-sensed vegetation indices recorded at or near FCRN sites during this period. Collectively, results from this study indicate that continental-scale patterns of weather are reflected in those of NEP, although these patterns may vary depending on local climate, topography and forest type. Thus El Niño may lower NEP of a coastal temperate forest stand but raise that of continental boreal forest stands, or drought may lower NEP in a well-drained boreal forest stand but not in a poorly-drained one. Keywords: Diagnosis, Attribution, Site-level Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 132: Estimates of terrestrial carbon cycle model parameters by assimilation of FLUXNET data: Do parameter variations cause bias in regional flux estimates?

132: Estimates of terrestrial carbon cycle model parameters by assimilation of FLUXNET data: Do parameter variations cause bias in regional flux estimates? Daniel M Ricciuto, Oak Ridge National Laboratory, ricciutodm@ornl.gov (Presenting) Anthony W King, Oak Ridge National Laboratory, kingaw@ornl.gov Lianhong Gu, Oak Ridge National Laboratory, lianhong-gu@ornl.gov Wilfred M Post, Oak Ridge National Laboratory, wmp@ornl.gov Although estimates of the magnitude of the North American terrestrial carbon sink are converging, the interannual variability of this sink and its driving mechanisms are still poorly understood. Confronting terrestrial carbon cycle models with observational data improves model predictions, allows for statistical quantification of uncertainties and aids model development by limiting parametric uncertainty and highlighting structural errors. We perform data assimilation on the Local Terrestrial Ecosystem Carbon (LoTEC) model using net ecosystem exchange, latent heat flux and available ancillary data from twenty-five FLUXNET sites with multiyear records in North America covering five key biomes. Parameters estimated include those associated with photosynthesis, heterotrophic and autotrophic respiration, phenology, hydrology and initial carbon pools. We find that assimilated parameter values deviate significantly from prior assumptions, vary spatially within a single biome and vary temporally at a single site. The traditional assumption in many regional biogeochemical models of a uniform parameter set within a biome is therefore invalid, but the uncertainty in regional flux predictions resulting from this error is difficult to quantify. If parameter variations are random, errors will average out and the regional flux uncertainty will be small; however, if parameter variations are correlated with driving variables such as temperature or precipitation, large biases may occur within a region and uncertainties will be larger. We test for correlations of assimilated parameters with driving variables and quantify the resulting regional uncertainty in the LoTEC model using a pseudodata experiment. Keywords: Attribution, Prediction, Site-level Synthesis

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133: Improving carbon flux predictions in North America from the bottom up: The current state of eddy covariance based model-data fusion

133: Improving carbon flux predictions in North America from the bottom up: The current state of eddy covariance based model-data fusion Daniel M Ricciuto, Oak Ridge National Laboratory, ricciutodm@ornl.gov (Presenting) Kenneth J. Davis, Pennsylvania State University, davis@meteo.psu.edu Ankur R Desai, University of Wisconsin - Madison, desai@aos.wisc.edu Andrew M Fox, University of Sheffield, a.m.mfox@sheffield.ac.uk Michael C Dietze, University of Illinois, mdietze@life.illinois.edu Shuguang Liu, USGS Earth Resources Observation and Science Center, sliu@usgs.gov Yiqi Q Luo, University of Oklahoma, yluo@ou.edu Andrew D Richardson, University of New Hampshire, andrewr@solo.sr.unh.edu Kevin Schaefer, National Snow and Ice Data Center, University of Colorado, kevin.schaefer@nsidc.org Mathew Williams, University of Edinburgh, mwilliam@staffmail.ed.ac.uk Data from research sites that use the eddy covariance method are proving to be indispensible for characterizing the carbon and energy budgets of ecosystems, for testing and improving terrestrial carbon cycle models, and for bridging the gap between process-level understanding and regional-scale carbon dynamics. Recent advances in computational tools and data assimilation algorithms have enabled a wide array of model-data fusion techniques in which carbon cycle observations are used to constrain model parameters. These parameters generally include photosynthetic parameters associated with a Farquhar or light-use efficiency model, heterotrophic and autotrophic respiration parameters, hydrological parameters and sometimes initial conditions. The data assimilation techniques (e.g., Ensemble Kalman Filter (EnKF) and Markov Chain Monte Carlo (MCMC)) and models vary greatly in complexity and parameterization. Model data-fusion studies generally report greatly improved model performance in carbon fluxes from diurnal to seasonal timescales with mixed results in other variables such as long-term carbon pools. However, a recent intercomparison indicates that model-data fusion results are highly dependent upon methodology, initial conditions, cost function and other simplifying assumptions. Much work remains to translate estimated model parameters to reliable predictions of future carbon fluxes. Accurate predictions of future fluxes also require data constraints beyond eddy covariance observations such as forest inventory data and remote sensing. Despite these challenges, model-data fusion can provide improved model parameterizations, easier identification of model structural insufficiencies, optimal new observation strategies, and regional flux predictions with statistically-based uncertainty estimates that are currently lacking. Here we synthesize recent progress in eddy covariance based model-data fusion studies. We also present preliminary results from an interim synthesis activity designed to quantify model and methodological uncertainty by inviting participants to use a common set of drivers and constraints at several North American eddy covariance sites with long data records. Keywords: Attribution, Prediction, Site-level Synthesis 134: Site Level Evaluation of MODIS Albedo and Reflectance Anisotropy Gap-free Products for NACP

134: Site Level Evaluation of MODIS Albedo and Reflectance Anisotropy Gap-free Products for NACP Crystal B. Schaaf, Center for Remote Sensing, Boston University, schaaf@bu.edu (Presenting) Miguel O. Román, Center for Remote Sensing, Boston University, mroman@bu.edu Qingling Zhang, Center for Remote Sensing, Boston University, zql@bu.edu Zhuosen Wang, Center for Remote Sensing, Boston University, wangzhs@bu.edu Xiaoyuan Yang, Center for Remote Sensing, Boston University, xiaoyuan@bu.edu Curtis Woodcock, Center for Remote Sensing, Boston University, curtis@bu.edu Alan H. Strahler, Center for Remote Sensing, Boston University, alan@bu.edu Measuring changes in satellite-derived albedo and reflectance anisotropy through time provides the best quantitative means for tracking land surface variability and measuring changes in terms that can be directly utilized by global and regional carbon and energy balance applications. Gap-free 500m reflectance anisotropy models of North America have been prepared to provide albedo and nadir BRDF-adjusted reflectance (NBAR) values for use in NACP investigations. These products use the annual temporal cycle of the retrieved surface anisotropy (BRDF) model at each pixel to estimate missing periods and capture the full phenological and radiation regimes of the surface. The reconstructed surface reflectance anisotropy models can then be used to estimate clear-sky albedo and NBAR values under realistic atmospheric and illumination conditions. Evaluation of these satellite-derived biophysical quantities has been undertaken at a number of Ameriflux, ARM and SURFRAD/BSRN tower sites using a rigorous upscaling scheme that combines in-situ and MODIS retrievals in a geostatistical framework. Semivariogram functions, derived from high resolution scenes (e.g. ETM+ and ASTER), are used to assess whether each of the tower-measured footprints are representative samples of the larger landscapes that surround them. The suitability of such assessments needs to be assessed at least seasonally to capture the annual variability of each site. Accordingly, MODIS retrievals can then be evaluated either (1) against ground observations that consistently match the sensor’s field of view or reflect a homogeneous spatial distribution; or (2) by partitioning MODIS retrievals according to a PFT-based classification as generally adopted by ecosystem, climate, and weather forecast models. These evaluations will provide improved pixel-specific accuracies for regional and global modeling efforts. A summary of the current status of the field validation efforts, as well as an overview of on-going dataset applications and anticipated enhancements, will be presented.

Keywords: Site-level Synthesis, Regional/Continental Synthesis 135: A geostatistical synthesis study of factors affecting net ecosystem exchange in different ecosystems of North America

135: A geostatistical synthesis study of factors affecting net ecosystem exchange in different ecosystems of North America Vineet Yadav, The University of Michigan, vineety@umich.edu (Presenting) Anna M Michalak, The University of Michigan, amichala@umich.edu Kim Mueller, The University of Michigan, kimlm@umich.edu Plant ecosystem dynamics are multifaceted and have a significant impact on global carbon fluxes (Net ecosystem exchange). Laboratory scale, process level understanding of plant function and physiology has improved considerably over last half century; however, the understanding of different process pathways and their sensitivity to environmental controls at various temporal scales is fragmented and uncertain. This study contributes to reducing this uncertainty through the application of a geostatistical regression in a linear and non-linear

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framework, coupled with Bayesian model selection, to assess the contribution of different environmental stimuli, energy fluxes, and indirect indices of plant physiology, to observed variability in carbon flux at nine AmeriFlux sites throughout North America. A total of 12 covariates were considered, including (1) Composed LAI (2) Composed FPAR (3) Composed EVI (4) Composed NDVI (5) Vapor pressure deficit (6) Global radiation (7) Air temperature (8) Precipitation (9) Soil temperature (10) Soil water content (11) Sensible heat index and (12) Latent heat index. Observed carbon fluxes were analyzed at daily, eight day and monthly time scale, for the period 2001 to 2005. Global radiation was found to be the dominant control influencing carbon flux for all examined sites. Apparent controls of carbon flux differed significantly, even for similar vegetation types separated by short distances. In addition, the presented approach was able to explain a larger fraction of the observed variability for sites exhibiting strong seasonality. Keywords: Attribution, Site-level Synthesis 136: Uncertainties in carbon residence time and sequestration in terrestrial ecosystems of the conterminous USA: A Bayesian approach

136: Uncertainties in carbon residence time and sequestration in terrestrial ecosystems of the conterminous USA: A Bayesian approach Xuhui Zhou, University of Oklahoma, zxuhui14@ou.edu (Presenting) Tao Zhou, Beijing Normal University, tzhou@bnu.edu.cn Yiqi Luo, University of Oklahoma, yluo@ou.edu Carbon (C) residence time is one of the key factors determining the capacity of C storage in plant and soil pools. However, uncertainties of C residence times have not been well quantified, especially at regional scales. In this study, the Bayesian probability inversion and Markov Chain Monte Carlo (MCMC) technique were applied to a regional terrestrial ecosystem (TECO-R) model to quantify C residence times and assess their uncertainties in the conterminous USA. Our results show that almost all parameters are nearly Gaussian distributed but with considerably different variability. Most parameters with large variability were related to litter pools due to lack of experimental data. Estimated ecosystem C residence times ranged from 16.6 ± 1.8 (Cropland) to 85.9 ± 15.3 years (Evergreen needleleaf forest, ENF) with an average of 56.8 ± 8.8 years in the conterminous USA. The ecosystem C residence times and their standard deviations were spatially heterogeneous and varied with vegetation types and climate conditions. Large uncertainties, representing by coefficient of variance (CV), appeared in the southern and eastern USA. Driven by current increases in net primary production (NPP), terrestrial ecosystems in the conterminous USA sequestered 0.20 ± 0.06 Pg C yr-1. The spatial pattern of ecosystem C sequestration was closely related to the greenness map in the summer, ranging from -60 to 140 g C m-2 yr-1 with larger sequestration in central and southeast regions. Uncertainties of C residence times were spatially related to distribution of data points, while uncertainties of ecosystem C sequestration were related to C residence times and NPP. Our results suggest that the Bayesian approach with MCMC inversion provides an effective tool to estimate spatially distributed C residence time and assess their uncertainties in the conterminous USA. Keywords: Diagnosis, Attribution

Regional Synthesis Posters 137: The North-South gradient of CO2 in the free troposphere during summer: Implications for surface exchange.

137: The North-South gradient of CO2 in the free troposphere during summer: Implications for surface exchange. Gretchen Keppel Aleks, California Institute of Technology, gka@gps.caltech.edu (Presenting) Paul O Wennberg, California Institute of Technology, wennberg@caltech.edu (Presenting) Tapio Schneider, California Institute of Technology, tapio@gps.caltech.edu Stephanie A Vay, NASA LaRC, stephanie.a.vay@nasa.gov Ground-based remote sensing and in situ observations made in the free troposphere during summer reveal surprisingly large North-South gradients in atmospheric CO2. Ground-based FTS data from the TCCON site at Park Falls Wisconsin demonstrate that approximately 1/2 of the variability in total column CO2 can be explained simply by advection of free tropospheric air by weather fronts. This finding is corroborated by free tropospheric aircraft data obtained during summer 2004 as part of INTEX-NA. We use the AM2 general circulation model to infer the N-S distribution of surface fluxes required to produce the observed atmospheric gradient. We find that standard estimates of surface exchange (e.g. CASA) significantly underestimate uptake of CO2 at mid and northern latitudes during the growing season. Keywords: Diagnosis, Regional/Continental Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 138: Validation of High Temporal Density Landsat Time Series Disturbance Maps to Constrain Carbon Flux Estimates from NACP Ecosystem Process Models

138: Validation of High Temporal Density Landsat Time Series Disturbance Maps to Constrain Carbon Flux Estimates from NACP Ecosystem Process Models Warren B. Cohen, USDA Forest Service, warren.cohen@oregonstate.edu (Presenting) Zhiqiang Yang, Oregon State University, zhiqiang.yang@oregonstate.edu Robert E. Kennedy, Oregon State University, robert.kennedy@oregonstate.edu David P. Turner, Oregon State University, david.turner@oregonstate.edu Bev E. Law, Oregon State University, bev.law@oregonstate.edu Samuel N. Goward, University of Maryland, sgoward@umd.edu Jeffrey G. Masek, NASA Goddard, Jeffrey.G.Masek@nasa.gov Gretchen G. Moisen, USDA Forest Service, gmoisen@fs.fed.us Chengquan Huang, University of Maryland, cqhuang@umd.edu Jim Collatz, NASA Goddard, jim.collatz@nasa.gov Ecosystem process models ingest Landsat-based maps of forest disturbance to constrain estimates of carbon flux. Validating these forest disturbance maps helps with our understanding of the contributions of error from these maps in the overall error associated with estimates of

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carbon flux. Within NACP, we are working on two projects (ORCA and NAFD) where annual-density Landsat time series are being used to derive forest disturbance maps, which are then used to model carbon flux at regional and national scales over the past several decades. Landsat has always been well suited for change detection, but algorithms to process annual time series are new. We have developed two such algorithms, but validating the maps resulting from their use remains a critical need. Our poster will describe a tool developed to provide this validation. The tool (TimeSync) uses geographic coordinates for an area of interest to extract image chips from a time series stack for that area and its neighborhood. The times series of chips is displayed for easy viewing, along with a spectral plot of raw bands and indices over the time series for the area of interest. Using these two data visualization windows, one identifies changes that have occurred, if any, within the area of interest and uses a series of pick-lists associated with a relational database to label segments in the spectral profiles that are associated with cover changes in the area of interest. The process involves selection of time-series vertices that identify dates associated with start and end points of change segments, and the segments are labeled according to the cause of the observed change. The tool is linked to Google Earth which displays a recent high resolution image for detailed spatial reference (commonly a georeferenced aerial photograph or high resolution satellite image). Examples from Landsat datasets used on both our regional and national projects will be presented. Keywords: Attribution, Regional/Continental Synthesis 139: Modeling Global Atmospheric CO2 Fluxes and Transport Driven by Assimilated Meteorology

139: Modeling Global Atmospheric CO2 Fluxes and Transport Driven by Assimilated Meteorology S R Kawa, NASA's Goddard Space Flight Center, stephan.r.kawa@nasa.gov G James Collatz, NASA's Goddard Space Flight Center, jim.collatz@nasa.gov (Presenting) A Scott Denning, Colorado State University, denning@atmos.colostate.edu David J Erickson, Oak Ridge National Laboratory, erickson@ornl.gov Steven C Wofsy, Harvard University, swofsy@seas.harvard.edu Arlyn E Andrews, NOAA ESRL, arlyn.andrews@noaa.gov As we enter the new era of satellite remote sensing for CO2 and other carbon cycle-related quantities, advanced modeling and analysis capabilities are required to fully capitalize on the new observations. Model estimates of CO2 surface flux and atmospheric transport are required for initial constraints on inverse analyses, to connect atmospheric observations to the location of surface sources and sinks, and ultimately for future projections of carbon-climate interactions. It is desirable that these models are accurate and unbiased at time scales from less than daily to multi-annual and at spatial scales from several kilometers or finer to global. Here we focus on simulated CO2 fluxes from terrestrial vegetation and atmospheric transport mutually constrained by analyzed meteorological fields from the Goddard Modeling and Assimilation Office for the period 1998 through 2006. Use of assimilated meteorological data enables direct model comparison to observations across a wide range of scales of variability. The biospheric fluxes are produced by the CASA model at 1x1 degrees on a monthly mean basis, modulated 3-hourly with analyzed temperature and sunlight. Both physiological and biomass burning fluxes are derived using satellite observations of vegetation, burned area (as in GFED-2), and analyzed meteorology. For the purposes of comparison to CO2 data, fossil fuel and ocean fluxes are also included in the transport simulations. In this presentation we evaluate the model’s ability to simulate CO2 flux and mixing ratio variability in comparison to in situ observations at sites in North America and the continental tropics. The influence of key process representations is inferred. In general, the high degree of fidelity in these simulations leads us to anticipate incorporation of real-time, highly resolved observations into a multiscale carbon cycle analysis system that will begin to bridge the gap between top-down and bottom-up flux estimation, which is a primary focus of NACP. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis, MCI Synthesis 140: Contrasting the seasonal patterns of ecosystem-level photosynthesis, gross light-use efficiency and respiration across the circumpolar boreal region - a first cut

140: Contrasting the seasonal patterns of ecosystem-level photosynthesis, gross light-use efficiency and respiration across the circumpolar boreal region - a first cut Guillaume Drolet, University Laval,, Quebec City, Canada, guillaume.drolet.1@ulaval.ca (Presenting) Hank A. Margolis, University Laval,, Quebec City, Canada, hank.margolis@sbf.ulaval.ca Elizabeth M. Middleton, NASA-Goddard Space Flight Center, elizabeth.m.middleton@nasa.gov Anders Lindroth, Swedish University of Agricultural Sciences, anders.lindroth@nateko.lu.se David Hollinger, USDA Forest Service, davidh@hypatia.unh.edu Northern terrestrial ecosystems encompass a wide range of age classes, structures, disturbance histories, climate regimes, and plant functional types. All these factors contribute, alone or together, to shaping the seasonality and magnitude of carbon (C) fluxes and this has important implications for predicting the dynamics of C sources and sinks . Here, we compare the temporal patterns of gross ecosystem productivity (GEP), gross light-use efficiency (LUE), and ecosystem respiration (Reco) derived from data collected at more than 45 eddy covariance sites in the circumpolar boreal zone. We present the similarities and differences between these patterns and relate them to physical (e.g. climate, soil, latitude), biological (e.g. plant functional type, leaf area), or historical conditions (e.g., land use, disturbance) associated with the study sites. To explain the differences and similarities between the temporal patterns of GEP, LUE, and (Reco), we also contrast their environmental response functions to key variables well-known for their controls on ecosystem-level C cycling. All results presented here were extracted from the Fluxnet-La Thuile standardized dataset of eddy covariance, meteorological, and ancillary data coming from several flux stations distributed over North America, Iceland, Scandinavia, and Russia. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 141: Ensemble Ecosystem Model Experiment and Intercomparison using the Terrestrial Observation and Prediction System (TOPS)

141: Ensemble Ecosystem Model Experiment and Intercomparison using the Terrestrial Observation and Prediction System (TOPS) Weile Wang, NASA Ames Research Center/ORAU, weile.wang@gmail.com Jennifer L. Dungan, NASA Ames Research Center, jennifer.l.dungan@nasa.gov (Presenting) Andrew Michaelis, Cal. State Univ. Monterry Bay/NASA Ames Research Center, amac@hyperplane.org Hirofumi Hashimoto, Cal. State Univ. Monterry Bay/NASA Ames Research Center, hirofumi.hashimoto@gmail.com Ichii Kazuhito, Fukushima University, Japan, kichiijp@yahoo.co.jp Ramakrishna Nemani, NASA Ames Research Center, rama.nemani@nasa.gov

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Numerous efforts have begun to characterize a variety of sources of uncertainty in carbon flux estimates from both forward modeling and inverse modeling approaches. One source of uncertainty is structural, created by the variety of approaches taken to select and characterize the most important biogeochemical processes. To begin to explore this structural uncertainty, we have used an ensemble of well-known models including CASA, LPJ, and Biome-BGC with a consistent set of inputs for the period 1982-2006 for North America. The ensemble was run using input climate data interpolated from two sets of National Climate Data Center stations, Global Summary of the Day and NCDC Cooperative Summary of the Day, respectively. Model output variables (e.g. GPP) were analyzed according to their distributions in the climatological temperature-precipitation domain (that is, we bin simulation results of grid cells according to their “climate coordinates” instead of their geographic locations). These distributions concisely characterize the dynamics of different ecosystem models and thus facilitate comprehensive model intercomparisons as well as model-observation comparisons. Applying this method to analyze model-simulated carbon fluxes (GPP, NPP, and NEE) and flux-net measurements indicates general agreement but also remarkable differences, arising from the diverse approaches to characterize and parameterize ecosystem processes. Uncertainty due to the choice of a relatively sparse or dense climate station network was smaller than the structural uncertainty due to model choice. These results serve to highlight the problem inherent in relying on only one modeling approach to map surface carbon fluxes. They also emphasize the pressing necessity of expanded and enhanced monitoring systems to narrow critical structural and parametric uncertainties among ecosystem models. Keywords: Diagnosis, Regional/Continental Synthesis 142: CO2 Exchange and Budget of Natural and Agricultural Ecosystems across the Great Plains of North America: Integration of Flux Tower Data

142: CO2 Exchange and Budget of Natural and Agricultural Ecosystems across the Great Plains of North America: Integration of Flux Tower Data Tagir G Gilmanov, South Dakota State University, tagir.gilmanov@sdstate.edu (Presenting) Larry L Tieszen, USGS EROS Center, tieszen@usgs.gov Bruce K Wylie, USGS EROS Center, wylie@usgs.gov Li Zhang, CEODE CAS, lizhang@ceode.ac.cn John M Baker, USDS-ARS, john.baker@ars.usda.gov Carl J Bernacchi, Illinois State Water Survey, bernacch@uiuc.edu David P Billesbach, University of Nebraska Lincoln, dbillesbach1@unl.edu James A Bradford, USDA-ARS, jim.bradford@ars.usda.gov David R Cook, Argonne National Laboratory, drcook@anl.gov Richard L Coulter, Argonne National Laboratory, rlcoulter@anl.gov Andrew G Detwiler, South Dakota School of Mines and Technology, andrew.detwiler@sdsmt.edu William A Dugas, Texas AgriLife Research, w-dugas@tamu.edu Lawrence B Flanagan, University of Lethbridge, larry.flanagan@uleth.ca Albert B Frank, USDA-ARS, franka@bis.midco.net Timothy J Griffis, University of Minnesota, tgriffis@soils.umn.edu Marshall R Haferkamp, USDA-ARS, marshall@larrl.ars.usds.gov Jay M Ham, Kansas State University, jayham@ksu.edu James L Heilman, Texas A&M University, j-heilman@tamu.edu Mark W Heuer, ATTD/NOAA, mark.heuer@noaa.gov Steven E Hollinger, Illinois State Water Survey, hollingr@uiuc.edu Roser Matamala, Argonne National Laboratory, matamala@anl.gov Tilden P Meyers, ATTD/NOAA, tilden.meyers@noaa.gov Patricia C Mielnick, Blackland AREC, patm@tamu.edu Jack A Morgan, USDA-ARS, jack.morgan@aars.usda.gov Clenton E Owensby, Kansas State University, owensby@ksu.edu John H Prueger, National Soil Tilth Laboratory, john.prueger@ars.usda.gov Phillip L Sims, USDA-ARS, psims@spa.ars.usds.gov Margaret S Torn, Lawrence Berkeley National Laboratory, mstorn@lbl.gov The Great Plains are important for understanding continental carbon budgets. They encompass broad climate gradients of temperature and moisture and include native tallgrass, mixedgrass, and shortgrass systems, grazing lands, and land that has been converted to more intensive agricultural use. We partitioned data sets of CO2 exchange Fc measured at 29 flux-tower sites representing 32 ecosystems and 88 site-years into gross primary productivity Pg and ecosystem respiration Re components using the light-temperature-response method for gap filling. Annual totals of gross primary production, ecosystem respiration, and net CO2 exchange were calculated to characterize the temporal dynamics and geographic patterns of sink/source activity in the Great Plains. Numerical estimates of major ecosystem-scale physiological parameters (apparent quantum yield, photosynthetic capacity, daytime ecosystem respiration rate, and light-use and water-use efficiencies) were derived and their geographic patterns described. Multivariate statistics and time-series analyses identified relationships between Pg and Re at the daily and 8-day steps and the major on-site environmental variables measured at the tower sites: weather (incoming radiation, temperature, relative humidity, precipitation/soil moisture), vegetation (aboveground phytomass, leaf area index, C3/C4 composition), soil (texture, moisture, chemistry), management treatments, and remotely sensed spectral indices (normalized difference vegetation index NDVI, normalized difference water index NDWI, etc.). Data-driven multivariate phenomenological models Pg = Fp(Xi1, Xi2, …, Xim) and Re = Fr(Xj1, Xj2, …, Xjn) were constructed to describe the effect of factors-predictors Xij on gross primary productivity and ecosystem respiration. Appropriate GIS layers Xij) were characterized at the USGS EROS Center and the GIS-based methods were developed to apply these models to scale-up tower measurements to the ecoregions of the Great Plains, generate spatial and temporal maps of CO2 exchange, and calculate carbon budgets. This phenomenological approach yielded robust and physiologically meaningful results that complement the detailed process-based simulation modeling systems. Keywords: Diagnosis, Attribution, Decision Support, Site-level Synthesis, Regional/Continental Synthesis 143: The ORCA West Coast Regional Project - Constraining Carbon Budgets on Regional Scales using Atmospheric Inverse Modelling Techniques

143: The ORCA West Coast Regional Project - Constraining Carbon Budgets on Regional Scales using Atmospheric Inverse Modelling Techniques Mathias Goeckede, Oregon State University, College of Forestry, mathias.goeckede@oregonstate.edu (Presenting)

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Anna Michalak, University of Michigan, Department of Civil and Environmental Engineering, and, Department of Atmospheric, Oceanic and Space Sciences, anna.michalak@umich.edu Dean Vickers, Oregon State University, College of Oceanic and Atmospheric Sciences, vickers@coas.oregonstate.edu David Turner, University, College of Forestry, david.turner@oregonstate.edu Beverly Law, University, College of Forestry, bev.law@oregonstate.edu The ORCA project aims at determining the regional carbon balance of Oregon, California and Washington, with a special focus on the effect of disturbance history and climate variability on carbon sources and sinks. ORCA provides a regional test of the overall NACP strategy by demonstrating bottom-up and top-down modeling approaches to derive carbon balances at subregional to regional scales. The ORCA top-down modeling component has been set up to capture flux variability on the regional scale at high temporal and spatial resolution. Atmospheric transport is simulated coupling the mesoscale model WRF (Weather Research and Forecast) with the STILT (Stochastic Time Inverted Lagrangian Transport) footprint model. Continuous atmospheric CO2 concentration data are taken from high-precision monitoring sites and flux sites from the AmeriFlux network. Terrestrial biosphere carbon fluxes are simulated at a spatial resolution smaller than 1km and subdaily timesteps, considering effects of ecoregion, land cover type and disturbance regime on the carbon budgets. Flux computation assimilates high-resolution remote sensing products (e.g. LandSat, MODIS) and interpolated surface meteorology (DayMet, SOGS, PRISM). We present results on West Coast regional carbon budgets that have been optimized using Bayesian inversion and the information provided by the network of CO2 observation sites. We address the influence of spatial and temporal resolution in the general modeling setup, and test the level of detail that can be resolved by top-down modeling on the regional scale, given the uncertainties introduced by various sources for model-data mismatch. Application of the approach highlights the strong regional variability in CO2 exchange rates on the regional scale. For the West Coast domain, we found that this type of model must account for water availability and drought stress to avoid overestimating terrestrial sinks for CO2. Results could be further improved by systematically expanding the observation network, i.e. to sample underrepresented biomes or regions. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 144: Role of Forest 'Disturbance' and Regrowth in North American Carbon Balance

144: Role of Forest 'Disturbance' and Regrowth in North American Carbon Balance Samuel N. Goward, Geography, University of Maryland, sgoward@umd.edu (Presenting) Warren B. Cohen, U.S. Forest Service, Pacific Northwest Region, warren.cohen@oregonstate.edu Jeffery G. Masek, Biospheric Sciences, NASA Goddard Space Fight Center, warren.cohen@oregonstate.edu Gretchen Moisen, U.S. Forest Service, Rocky Mountain Region, gmoisen@fs.fed.us North America is currently a net carbon source to the atmosphere, largely because of fossil fuel emissions, with approximately 30% of these emissions offset by vegetation growth (CCSP, 2007). North American forests are thought to be a long-term sink for atmospheric carbon, with much of the sink attributed to either forest regrowth from past agricultural clearing or to woody encroachment. However, the magnitude of the North American forest sink is uncertain, because disturbance and regrowth dynamics are not well characterized or understood. Disturbance events (including harvest, fire, insect and storm damage, and disease) strongly affect carbon dynamics in many ways, including biomass removal, emissions from decaying biomass, and changes in productivity. Uncertainties related to disturbance and subsequent regrowth make it difficult to predict if North American forests and woodlands will continue to absorb atmospheric carbon for the foreseeable future. Keywords: Attribution, Regional/Continental Synthesis 145: Influences of the spatial and temporal resolutions of CO2 concentrations on model estimates of terrestrial carbon budget: Implications for the ASCENDS

145: Influences of the spatial and temporal resolutions of CO2 concentrations on model estimates of terrestrial carbon budget: Implications for the ASCENDS Lianhong Gu, Oak Ridge National Lab, lianhong-gu@ornl.gov (Presenting) Tony King, ORNL, kingaw@ornl.gov Mac Post, ORNL, wmp@ornl.gov Dan Riciutto, ORNL, ricciutodm@ornl.gov Atmospheric CO2 concentration varies in space and time due to the uneven distributions of biogenic and anthropogenic carbon sources and sinks. Such variations are particularly large (>100ppm) over continents where terrestrial plants are located and human activities are concentrated (Figure 1). These dynamics, which superimpose on the long-term anthropogenic trend, are the basis for atmospheric inversion of carbon fluxes from CO2 concentration measurements. However, global carbon cycle models in general assume uniform CO2 distribution over the earth surface and don’t resolve CO2 concentration for time scales less than a year. In this study, we investigate how the spatial and temporal resolutions of CO2 concentration affect the estimates of terrestrial carbon budgets and discuss the implications for the goal of the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission regarding the quantification of global spatial distributions of atmospheric CO2 on scales of weather models. Keywords: Attribution, Prediction, Site-level Synthesis, Regional/Continental Synthesis 146: Estimating bias of scaling effects on satellite based forest area estimation for the conterminous U.S.

146: Estimating bias of scaling effects on satellite based forest area estimation for the conterminous U.S. Daolan Zheng, University of New Hampshire, daolan.zheng@unh.edu Linda S. Heath, USFS Northern Research Station, lheath@fs.fed.us (Presenting) Mark J. Ducey, University of New Hampshire, mjducey@unh.edu We identified the scaling effects on forest area estimation for the conterminous U.S. using regression analysis and the National Land Cover Dataset 30-m satellite-derived maps in 2001 (for model development) and 1992 (for model validation). The original data were aggregated to two broad cover types (forest vs. non-forest) and two coarser resolutions (1 km and 10 km). Standard errors of the model estimates were

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2.3% for 1-km and 4.9% for 10-km resolutions respectively. At 1-km resolution, our model improved the accuracies for by 0.6% (12,556 km2) in 2001 and 1.9% (43,198 km2) in 1992, compared to the forest estimates before the adjustments. Using our model, we estimated that forest area observed from 2001 1-km MODIS (MODerate-resolution Imaging Spectroradiometer) land-cover map might differ by 80,811 km2 from what would be observed if MODIS was available at 30 m for the conterminous U.S. Of this difference, 46,870 km2 (or 58%) could be a relatively small net improvement, equivalent to 1.5% (or 1,444 Tg) of total nonsoil forest CO2 stocks. With increasing attention to accurate monitoring and evaluation of forest area changes for different regions of the globe, our results could facilitate the removal of bias from large-scale estimation based on remotely sensed information at coarse resolutions. Keywords: Regional/Continental Synthesis 147: Spatial Structure in North American Regional CO2 Fluxes Evaluated With a Simple Land Surface Model

147: Spatial Structure in North American Regional CO2 Fluxes Evaluated With a Simple Land Surface Model Timothy W Hilton, Pennsylvania State University, hilton@meteo.psu.edu (Presenting) Kenneth J. Davis, Pennsylvania State University, davis@meteo.psu.edu We evaluate spatial structure in Ameriflux CO2 flux observations using a simple diagnostic land surface model. The Vegetation Photosynthesis Respiration Model (VPRM) calculates NEE using locally observed temperature and PAR, and satellite-derived phenology and moisture. We use observed NEE from a group of 65 Ameriflux eddy covariance tower sites spanning North America to estimate VPRM parameters for these sites. We use the spatial structure of VPRM errors to investigate spatial coherence in regional CO2 fluxes at several different time scales. We find that strong spatial structure does exist in the data-model residuals. Preliminarily, this structure is not seen unless model parameters are estimated on a local basis. Finally, we use VPRM with our estimated parameter values to generate CO2 fluxes for the North American continent. We explore routes to integrate this result with atmospheric mixing ratio observations to reduce uncertainty in North American carbon dioxide fluxes. Keywords: Diagnosis, Regional/Continental Synthesis, MCI Synthesis 148: Comparing estimates of North American biospheric carbon flux from process-based models: New tools for understanding differences in predictions

148: Comparing estimates of North American biospheric carbon flux from process-based models: New tools for understanding differences in predictions Deborah N Huntzinger, University of Michigan, dnhuntzi@umich.edu (Presenting) Kim L Mueller, University of Michigan, kimlm@umich.edu Sharon J Gourdji, University of Michigan, sharongourdji@gmail.com Anna M Michalak, University of Michigan, amichala@umich.edu A number of process-based models have been developed to estimate the magnitude of carbon sources and sinks across regional and continental scales. The complexity of models varies significantly, ranging from simple associations between climate or other driver variables and carbon flux, to highly parameterized mechanistic models that include sophisticated plant physiological processes. Both the complexity of the system being modeled and the inherent differences among the various modeling approaches have made it difficult to ascertain which environmental and ecological drivers most strongly control carbon exchange and at what scale these drivers operate. This study presents the application of geostatistical tools and multi-linear regression methods to compare process-based estimates of land-atmosphere carbon exchange, with the goal of selecting methods of comparison which (1) highlight similarities and differences in the spatial and temporal distribution of estimated fluxes, and (2) which help to attribute the spatial variability in modeled fluxes to those environmental variables that appear most significant in controlling the overall trend of modeled NEE with space and time. Four biospheric or forward models are examined which range in complexity from simple (VPRM) to highly parameterized (CASA, CASA GFEDv2, and SiB 3.0). Results indicate that the examined biospheric models have significantly different spatial correlation lengths and degrees of variability when compared seasonally at the continental scale. A potential source of these differences is from regional variability in the different driver data used among the models, such as biome classification or vegetative cover class. Variable selection and regression analysis techniques indicate that, in general, the same environmental variables (e.g., evapotranspiration, radiation, temperature) appear to be correlated with estimated NEE on an annual basis, with greater than 50% of the observed variability in estimated fluxes from the models being described by simple linear relationships between key environmental drivers and flux. Keywords: Attribution, Regional/Continental Synthesis 149: Regional CO2 Fluxes Estimated over North America for 2004 using a Geostatistical Inverse Model

149: Regional CO2 Fluxes Estimated over North America for 2004 using a Geostatistical Inverse Model Sharon M Gourdji, Department of Civil & Environmental Engineering, University of Michigan, sharongourdji@gmail.com Kim L Mueller, Department of Civil & Environmental Engineering, University of Michigan, kimlm@umich.edu Deborah N. Huntzinger, Department of Civil & Environmental Engineering, University of Michigan, dnhuntzi@umich.edu (Presenting) Vineet Yadav, Department of Civil & Environmental Engineering, University of Michigan, vineety@umich.edu Adam I Hirsch, Global Monitoring Division, Earth System Research Laboratory, National Oceanic & Atmospheric Administration, adam.hirsch@noaa.gov Arlyn E Andrews, Cooperative Institute for Research in Environmental Sciences, University of Colorado, arlyn.andrews@noaa.gov Anna M Michalak, Department of Civil & Environmental Engineering, Department of Atmospheric, Oceanic & Space Sciences, University of Michigan, amichala@umich.edu Global inverse models have identified an overall CO2 sink in the Northern Hemisphere terrestrial biosphere, but the spatial distribution of the sink within the North American and Eurasian continents is still subject to high uncertainty. Regional-scale inverse models provide the opportunity to infer sub-continental scale CO2 fluxes, and have recently become feasible due to the availability of continuous atmospheric CO2 measurements at continental locations and improvements in high-resolution atmospheric transport models. In addition, the geostatistical approach to inverse modeling, in contrast to Bayesian approaches, can estimate CO2 sources and sinks at relatively fine resolution without the use of prior flux distributions from biospheric models, thereby providing an independent validation tool for bottom-up understanding of flux. The results from a regional geostatistical inversion study over North America (funded through the North American Carbon Program) are

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presented, which estimates CO2 fluxes at a 1°x1° spatial and an 8-day temporal resolution for 2004, using continuous atmospheric CO2 measurements from 9 continental tower locations and weekly flask measurements where available. Auxiliary variables significantly related to flux (e.g. Leaf Area Index, Fire Counts or Population Density) are selected using statistical variable selection techniques, and then incorporated directly into the inverse model. These variables help to constrain 1°x1° fluxes in areas under-sampled by the atmospheric measurement network, while their relationships to flux, as estimated by the inversion, provide insight into the magnitude of the processes controlling CO2 flux variability as seen through the atmospheric data. Net annual fluxes are compared to output from two biospheric models to identify regions within North America where bottom-up and top-down methods for flux estimation converge for this year. Overall, this poster will focus on the U.S. NACP science questions relating to diagnosis and attribution of the North American carbon cycle. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 150: Vulnerability of North American black spruce forests to changes in post fire succession

150: Vulnerability of North American black spruce forests to changes in post fire succession Eric S. Kasischke, University of Maryland, ekasisch@umd.edu (Presenting) Jill F. Johnstone, University of Saskatchewan, jill.johnstone@usask.ca Merritt R. Turetsky, University of Guelph, mrt@uoguelph.ca Laura L. Bourgeau-Chavez, Michigan Tech Research Institute, laura.chavez@mtu.edu Aditi Shenoy, University of Alaska, aditi.shenoy@gmail.com Knut Keilland, University of Alaska, ffkk@uaf.edu Matthew Borr, University of Maryland, mborr@umd.edu Kirsten Barrett, U.S. Geological Survey, kirstenne@gmail.com Elizabeth Hoy, University of Maryland, elizabeth.hoy@gmail.com Tatiana Loboda, University of Maryland,, tloboda@hermes.geog.umd.edu A. David McGuire, University of Alaska, ffadm@uaf.edu T. Scott Rupp, University of Alaska, ffsr@uaf.edu This NASA sponsored NACP project is focusing on understanding and quantifying factors that influence changes in post-fire succession in black spruce ecosystems, the most common forest type found in the North American boreal forest. This study involves collection and analysis of field data, analysis of spatial/temporal characteristics of fire based on an integrated assessment of geospatial data sets, monitoring post-fire variations in regeneration using satellite remote sensing data, and assessment of the impacts of variations in climate and fire severity on ecosystem distribution and carbon cycling using process based models. To date, the results from these studies have shown: (a) variations in fire severity, climate, and meta-population dynamics combine to control post-fire regeneration in black spruce forests, in particular, deciduous tree recruitment and growth does not occur unless < 3 cm of organic matter remains after a fire; (b) frequency of deep burning fires in black spruce forests is controlled by topography and seasonality of burning, with lowland and north aspect sites being most resistant to deep burning fires; and (c) black spruce forests on lowland sites burn less frequently than on upland sites. Keywords: Attribution, Site-level Synthesis, Regional/Continental Synthesis 151: Synthesizing Prediction Uncertainty From Interim Syntheses

151: Synthesizing Prediction Uncertainty From Interim Syntheses Anthony Wayne King, Oak Ridge National Laboratory, kingaw@ornl.gov (Presenting) Wilfred M Post, Oak Ridge National Laboratory, wmp@ornl.gov Dan Ricciuto, Oak Ridge National Laboratory, ricciutodm@ornl.gov The Interim Synthesis Activities of the North American Carbon Program (NACP) promise to reveal understanding of the forces responsible for temporal and geographical patterns of terrestrial and coastal ocean sources and sinks of atmospheric carbon dioxide. The Regional Interim Synthesis focuses on interannual variability in carbon sources and sinks across North America as predicted by “forward” or “bottom-up” terrestrial carbon models and “inversion” or “top-down” atmospheric models. The Site Interim Synthesis focuses on uncertainty in both the site-scale carbon dioxide fluxes observed by eddy-covariance methods and in the prediction of those fluxes by ecosystem models. Both syntheses provide useful information: what are the likely causes of interannual variability in sources and sinks (attribution) and how well – with what certainty – can we expect to simulate future sources and sinks given scenarios of future climate change (prediction). Here we provide a synthesis of the syntheses, looking for insights into attribution and prediction with uncertainty as they are used in decision support. We examine results from models used simultaneously in both the Regional and Site syntheses. What does the uncertainty analysis of the Site Synthesis “say” about model and data uncertainty surrounding the attribution analysis of the Regional Synthesis? If drought is implicated as a major driver of interannual changes in regional sources and sinks, with what certainty might these models project future changes given a prescribed future climate. For one of the models, LoTEC (Local Terrestrial Ecosystem Carbon) we also examine the understanding of uncertainty at the site-scale gained from using the model in conventional forward-modeling mode and in site-scale data assimilation mode. How does understanding of uncertainty in attribution vary between these two modes of simulation, and what are the implications of these differences for the uncertainty in predicting future changes in terrestrial sources and sinks. Keywords: Attribution, Prediction, Site-level Synthesis, Regional/Continental Synthesis 153: Measuring regional CO2 fluxes using a Lagrangian approach

153: Measuring regional CO2 fluxes using a Lagrangian approach Douglas K Martins, Purdue University, dmarti18@purdue.edu (Presenting) Colm Sweeney, National Oceanic and Atmospheric Administration, colm.sweeney@noaa.gov Brian H Stirm, Purdue University, stirmb@purdue.edu Paul B Shepson, Purdue University, pshepson@purdue.edu The difficulty of measuring regional fluxes of CO2 has limited our understanding of the global carbon budget and the processes controlling carbon exchange across politically relevant spatial scales. A Lagrangian experiment was conducted over Iowa on June 19, 2007 as part of the North American Carbon Program’s Mid-Continent Intensive using a light-weight, cost-effective aircraft to measure a net drawdown of CO2 concentration within the boundary layer. The drawdown is related to photosynthetic uptake when emission footprints are considered using a

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combination of emission inventories from the Vulcan project and HYSPLIT source contributions. Results show a total average CO2 flux of −5.3±0.7 µmol m-2 s-1. The average fluxes from fossil fuels over the measurement area are 2.8±0.4 µmol m-2 s-1. Thus, the CO2 flux attributable to the vegetation is −8.1±0.8 µmol m-2 s-1. The magnitude of the vegetative flux is comparable to other studies using the Lagrangian approach, but it is smaller than tower-based eddy covariance fluxes over the same period and measurement area. Sensitivities to analysis procedures and discrepancies between aircraft and tower-based measurements are discussed. We describe an aircraft Lagrangian experiment that offers direct, reliable, and cost-effective means for measuring CO2 fluxes at regional scales that can be used to compare to ecosystem models or to satellite measurements. Keywords: Diagnosis, Attribution, Decision Support, Regional/Continental Synthesis, MCI Synthesis 154: Modeling ecosystem-level carbon fluxes using an advanced land surface model (FAPIS) coupled to the Regional Atmospheric Modeling System (RAMS).

154: Modeling ecosystem-level carbon fluxes using an advanced land surface model (FAPIS) coupled to the Regional Atmospheric Modeling System (RAMS). Jesse N Miller, Oak Ridge National Lab, millerjn@ornl.gov (Presenting) Lianhong Gu, Oak Ridge National Lab, lianhong-gu@ornl.gov Wilfred M. Post, Oak Ridge National Lab, wmp@ornl.gov FAPIS-RAMS, is a newly developed ecosystem/atmospheric transport model. It consists of the Regional Atmospheric Modeling System (RAMS), a numerical prediction model that is used to simulate atmospheric circulations at the mesoscale, and the Fluxes and Pools Integrated Simulator (FAPIS), which is a fully-developed terrestrial ecosystem land surface model. In the FAPIS-RAMS tool LEAF2 of RAMS is replaced by FAPIS. FAPIS couples processes of radiative transfer, photosynthesis, transpiration, leaf energy balance, soil energy balance and turbulence transfer. Several unique features of FAPIS make it a preferred land surface model for studying carbon dynamics. The complete ecosystem carbon cycle, including the components of net ecosystem exchange (NEE) and especially gross primary productivity, is computed in a way that is consistent with water and energy fluxes. FAPIS uses a structured canopy with multiple layers and exchange between the canopy and the atmosphere is computed directly, taking into account within canopy gradients of CO2 concentration, temperature, humidity and winds. This allows for precise description of spatial surface fluxes. As an illustrative example, FAPIS-RAMS is run over Missouri with nested grids centered over the MOFLUX tower location. It is forced with meteorological data from the North American Regional Reanalysis and initialized with a horizontally-homogeneous CO2 concentration field. Predicted NEE is compared to measurements from the MOFLUX site. This research addresses the objectives of the NACP by providing a modeling tool that can be used to diagnose and predict short-term spatially-explicit carbon sources and sinks. In addition, FAPIS-RAMS could provide a bottom-up approach for estimating terrestrial CO2 fluxes using atmospheric concentration (tall towers, Orbiting Carbon Observatory) and land surface flux data (FLUXNET) using data assimilation methods that could be comparable to results from top-down approaches.

Keywords: Diagnosis, Attribution, Prediction, Regional/Continental Synthesis, MCI Synthesis 155: Temporal Variations of Carbon Fluxes in a Temperate Forest Ecosystem of Northern Mexico

155: Temporal Variations of Carbon Fluxes in a Temperate Forest Ecosystem of Northern Mexico Jose de Jesus Navar, CIIDIR-IPN Unidad Durango, jnavar@ipn.mx (Presenting) Forests play a key role in modulating the global carbon cycle. However, there is increasing evidence that climate modifies the rate of carbon fluxes in forest ecosystems. Statistical analysis on dasometric data of 36 permanent sampling sites measured in 1982, 1993, and 2004, located in temperate forests of central Durango, Mexico, and dendrochronological data for Pseudotsuga menziesii trees of temperate forests of Nuevo Leon, Mexico, tested the hypothesis that the variation of carbon flux would be explained partially by climate variations. Results indicated that mean carbon influxes for the periods of 1982-1993 and 1993-2004 were 1.55 and 1.25 Mg C ha-1 y-1. Mean annual radial growth for drought and wet periods are 1.18 mm and 0.82 mm y-1, respectively. Northern Mexico was hit by a drought spell in the 1990’s that reduced rainfall by 10-15% and carbon influxes were decreased by approximately 20% while radial growth of P. menziesii trees was reduced 30%. Therefore, drought spells feedback the augmenting of carbon stocks in the atmosphere and climate change. Climate change scenarios must help to understand carbon influxes in forest ecosystems and how these mechanisms feedback regional and global climates. Key words: Productivity, stand scale, climate controls, radial growth. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 156: Canopy nitrogen, carbon assimilation and albedo in temperate and boreal forests: functional linkages and potential climate feedbacks

156: Canopy nitrogen, carbon assimilation and albedo in temperate and boreal forests: functional linkages and potential climate feedbacks Scott V Ollinger, University of New Hampshire, scott.ollinger@unh.edu (Presenting) Andrew D Richardson, University of New Hampshire, andrew.richardson@unh.edu David Y Hollinger, USDA Forest Service, davidh@hypatia.unh.edu Mary E Martin, University of New Hampshire, mem@unh.edu Peter B Reich, University of Minnesota, preich@umn.edu Lucie C Plourde, University of New Hampshire, lucie.plourde@unh.edu Steve Frolking, University of New Hampshire, steve.frolking@unh.edu The availability of nitrogen represents a key constraint on carbon cycling in terrestrial ecosystems and it is largely in this capacity that the role of nitrogen in the Earth's climate system has been considered. Despite this, few studies have included continuous variation in plant N status as a driver of broad-scale carbon cycle analyses. This is partly due to uncertainties in how leaf-level physiological relationships scale to whole ecosystems and because methods for regional to continental detection of plant N concentrations have yet to be developed. Here, we show that ecosystem CO2 uptake capacity in temperate and boreal forests scales directly with whole-canopy nitrogen concentrations, mirroring a leaf-level trend that has been observed for woody plants worldwide. We further show that both CO2 uptake capacity and canopy

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nitrogen concentration are strongly and positively correlated with shortwave surface albedo. These results suggest that nitrogen plays an additional, and previously overlooked, role in the climate system via its influence on vegetation reflectivity and shortwave surface energy exchange. We also demonstrate that much of the spatial variation in canopy nitrogen can be detected using broad-band satellite sensors, offering a means through which these findings can be applied towards improved application of coupled carbon cycle-climate models. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 157: Optimizing Large Scale Carbon Fluxes for North America

157: Optimizing Large Scale Carbon Fluxes for North America Andrew E. Schuh, Colorado State University, aschuh@atmos.colostate.edu (Presenting) A. Scott Denning, Colorado State University, denning@atmos.colostate.edu K. D. Corbin, Colorado State University, kdcorbin@atmos.colostate.edu M. Ulliasz, Colorado State University, marek@atmos.colostate.edu N. C. Parazoo, Colorado State University, nparazoo@atmos.colostate.edu We combine the SiB3 biosphere model with the RAMS mesoscale meteorology model and associated Lagrangian particle dispersion model (LPDM) and use CO2 observations from a 8-tower network in 2004 to correct a priori net ecosystem exchange of carbon. This work is unique in that it assumes no biome aggregation, is based upon high scale a priori carbon fluxes and meteorology, and estimates ecosystem respiration (ER) and gross primary productivity (GPP) fluxes separately for a domain consisting of most of North America. Results are presented as weekly corrections to ER, GPP, and NEE for 2004. Mechanistic hypotheses are presented for the spatial and temporal pattern of flux optimizations which include parallel reductions in ER and GPP as well as a carbon sink when aggregated to continental scales. The sensitivities of the inversion to independently derived boundary conditions, different fossil fuel sources, and various parameters in the inversion are analyzed and discussed. Keywords: Diagnosis, Regional/Continental Synthesis 158: The NOAA/ESRL tall tower and aircraft network: insights for the NACP and a vision for the future

158: The NOAA/ESRL tall tower and aircraft network: insights for the NACP and a vision for the future Colm Sweeney, CIRES, University of Colorado, colm.sweeney@noaa.gov (Presenting) Arlyn E Andrews, NOAA Earth System Research Lab, arlyn.andrews@noaa.gov (Presenting) Pieter Tans, NOAA Earth System Research Lab, pieter.tans@noaa.gov Over the last four years a major focus in the NOAA Earth System Research Laboratory’s carbon cycle group has been to build and maintain a tall tower and aircraft network for North America that will serve as a key element of the backbone observing system for the NACP. Currently, the network includes 16 aircraft sites and 7 fully instrumented tall tower sites. At each aircraft site a profile of 12 flask samples is completed at a biweekly to monthly frequency from 500 magl to 8000 masl. Each sample is analyzed for CO2, CO, CH4, SF6, N2O and H2 and a selection of over 40 other reactive and non-reactive trace gases including halocarbons, hydrocarbons and isotopes of CO2. The tall tower sites provide continuous measurements of CO2 and CO and basic meteorological parameters, along with daily afternoon flask samples that are analyzed for the same suite of gases as the aircraft samples. Three new tower sites were added in 2007 and one new site came online in August 2008. The tower network is providing detailed information about the processes controlling CO2 and other greenhouse gases in the planetary boundary layer. The tower dataset is characterized by features like the seasonal drawdown in CO2, mid-day and nighttime vertical gradients, large-scale horizontal gradients, and pollution events with unique chemical signatures. Clear disturbance signatures are evident in the record from the tower network, such as delayed uptake in the Midwest during summer 2008 resulting from late planting after the flooding and high carbon monoxide concentrations in the Sacramento Valley associated with biomass burning during late June/early July 2008. Data collected by the aircraft network is unique because of the spatial distribution of the sampling locations - both in the vertical and horizontal direction. Regular vertical profiles over the last 4 to 10 years from the aircraft network have allowed us to evaluate inversion models from the perspective of their underlying vertical and horizontal transport as well as their priors. Additionally, the aircraft network has allowed us to make regional estimates of carbon uptake that do not depend on prior flux estimates or numerical solutions of the tracer transport equation as required by traditional inversion estimates. The NOAA ESRL aircraft and tower network will continue to produce a benchmark dataset for evaluating inversion models and future satellite measurements. With the additional planned sites for tall towers and an increase in the frequency of the aircraft measurements operated by NOAA ESRL, we expect to resolve fluxes at higher resolution. However an integral component of the baseline atmospheric CO2 measurements will be partnerships with commercial airlines, universities and other groups such as state agencies that may be interested in achieving high spatial resolution over a particular domain. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 159: Bottom-up Scaling of Net Ecosystem Production and Net Biome Production over Oregon and California

159: Bottom-up Scaling of Net Ecosystem Production and Net Biome Production over Oregon and California David Turner, Oregon State University, david.turner@oregonstate.edu (Presenting) Beverly Law, Oregon State University, bev.law@oregonstate.edu Warren B. Cohen, Oregon State University, warren.cohen@oregonstate.edu David Ritts, Oregon State University, david.ritts@oregonstate.edu Zhiqiang Yang, Oregon State University, zhiqiang.yang@oregonstate.edu Tara Hudiburg, Oregon State University, tara.hudiburg@oregonstate.edu Maureen Duane, Oregon State University, maureen.duane@oregonstate.edu Application of spatially-distributed carbon cycle process models provides a means of integrating information on climate, soils, land cover, and disturbance regime. Here we applied the Biome-BGC model over Oregon and Washington with an emphasis on the period from 1980-2004. The model was adapted to simulate disturbance and recovery from multiple intensities of fire, harvest, and insect attack. It was also adapted

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to simulate crop growth and harvest. Disturbance history was prescribed based on a time series of Landsat images. Twenty-one percent of the forested area in Oregon underwent stand replacing disturbance (fire or clear cut) between 1972 and 2004. In recent years, net ecosystem production (NEP) was positive over most of the land base. On forest land, the net biome production (NBP) was ~ 50% of NEP. Accumulation of forest products was also a significant carbon sink. The forest sector carbon sink in this region has increased significantly since the 1980s because of harvest reduction on public lands (52% of forest land) and the approach to a stable age class distribution on private lands. Direct emissions from forest fires are generally small relative to NEP and harvest removals. The ratio of NBP to fossil fuel emissions is relatively small in California but can approach 0.5 in Oregon. Keywords: Diagnosis, Attribution, Regional/Continental Synthesis 160: Estimation of Evapotranspiration (ET) and Gross Primary Production (GPP) over North America

160: Estimation of Evapotranspiration (ET) and Gross Primary Production (GPP) over North America Wenping Yuan, National Research Council Postdoctoral Fellow, U.S. Geological Survey, Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota 57198, USA, wyuan@usgs.gov (Presenting) Shuguang Liu, U.S. Geological Survey, Earth Resources Observation and Science (EROS) center, Sioux Falls, South Dakota 57198, USA, sliu@usgs.gov The quantitative simulation of Gross Primary Production (GPP) at various spatial and temporal scales has been a major challenge for quantifying the global carbon cycle. We developed a light use efficiency model, called EC-LUE, driven by only four variables: Normalized Difference Vegetation Index (NDVI), Photosynthetically Active Radiation (PAR), air temperature, and the Bowen ratio of sensible to latent heat flux. The EC-LUE model makes it possible to map daily GPP over large areas because the potential light use efficiency (LUE) is invariant across various land cover types. However, previous applications of the EC-LUE model were hampered by poor predictions of evapotranspiration (ET) at large spatial scales. Accurate knowledge of spatiotemporal variation in ET is critical for a better understanding of the interactions between land surfaces and the atmosphere, and water and land resource management. In this study, we revised the Remote Sensing Penman-Monteith (RS-PM) model for estimating ET and used data from 41 eddy covariance flux towers to calibrate and validate the revised RS-PM model. The model explained 84% and 73% of the observed variations of ET for all of the calibration and validation sites, respectively. Using estimated ET as input, the EC-LUE model also had good performance in both calibration and validation sites, explaining 78% and 74% of the observed variation of GPP, respectively. A comparison with GPP calculated from the Moderate Resolution Imaging Spectroradiometer (MODIS) indicated that the EC-LUE model had better predictions of GPP at tower sites. The models simulated GPP and ET for contemporary climate using common, spatially explicit data sets for climate, NDVI and leaf area index (LAI) over all of North America. Keywords: Diagnosis, Decision Support, Site-level Synthesis, Regional/Continental Synthesis 161: Steps towards the use of the Canadian CBM-CFS3 in Mexico

161: Steps towards the use of the Canadian CBM-CFS3 in Mexico Bernardus de Jong, El Colegio de la Frontera Sur-Villahermosa, Mexico, bjong@ecosur.mx (Presenting) Marcela Olguin, El Colegio de la Frontera Sur-Villahermosa, Mexico, molguin@ecosur.mx Werner Kurz, Natural Resources Canada, Victoria, Canada, wkurz@pfc.cfs.nrcan.gc.ca Leonel Iglesias, Comisión Nacional Forestal, Zapopan, Mexico, liglesias@conafor.gob.mx Armando Alanís, Comisión Nacional Forestal, Zapopan, Mexico, jalanis@conafor.gob.mx As a non-annex 1 country of the United Nations Framework Convention on Climate Change, Mexico is requested to report the annual greenhouse gas balance of the various sectors, among others the land use, land-use change and forestry sector in a credible, verifiable, and transparent manner. In order to improve the capacity to estimate the carbon dynamics in forest ecosystems, the governments of México and Canada signed a Partnership in 2007 that included an evaluation of the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) as a potential tool to assist in the synthesis and integration of Mexico’s data on forest carbon and forest carbon dynamics. The main objective of the analysis is to test to what extend the CBM-CFS3 can contribute to meet Mexico’s monitoring and reporting requirements of forest carbon stocks and net emissions and removals of CO2-eq greenhouse gases. In the presentation we summarize the results from workshops, data compilation and testing of the Canadian model in Mexico. Also, we outline some of the next activities and key challenges for the full implementation of the CBM-CFS3 at the stand, regional and national level in Mexico.

Keywords: Diagnosis, Regional/Continental Synthesis, Software Tools, Instruments, Data Management, Programmatic Topics 162: Carbon stocks and emissions of Mexican forests and scrublands

162: Carbon stocks and emissions of Mexican forests and scrublands Marcela Olguin, El Colegio de la Frontera Sur-Villahermosa, Mexico, molguin@ecosur.mx Bernardus H.J. de Jong, El Colegio de la Frontera Sur-Villahermosa, Mexico, bjong@ecosur.mx (Presenting) Carlos Anaya, Centro de Estudios en Ecosistemas, Morelia, Mexico, carlos.anaya@ipicyt.edu.mx René Martinez, Centro de Estudios en Ecosistemas, Morelia, Mexico, redamar@oikos.unam.mx Omar Masera, Centro de Estudios en Ecosistemas, Morelia, Mexico, omasera@oikos.unam.mx Gabriela Guerrero, Centro de Estudios en Ecosistemas, Morelia, Mexico, gguerrer@oikos.unam.mx Since 1990s, Mexico has conducted three national inventories of GHG emissions. According to these, deforestation and forest degradation are the country’s second most important source of CO2 emissions after the energy sector. The presentation is part of Mexico’s most recent effort to update GHG inventory for the Land Use-Land Use Change and Forest (LULUCF) sector. Here, we summarize forest related CO2 emissions from deforestation and re-growth of biomass, applying the revised IPCC guidelines (1996). Our results include biomass data of 16,000 plots of the national forest inventory and land use-land cover dynamics between 1993 and 2002. In 2002, total stock of biomass carbon in natural undisturbed and disturbed ecosystems was estimated at 2.6 Pg C, of which 43% occurred in tropical highland forest, 38% in tropical lowland forest, 11% in scrubland and 7% in natural grassland. From 1993 to 2002, annual emissions consisted of 64.5 (± 12%) Tg CO2 y-1 from the combustion and decay of forest biomass, 4.9 (±259%) Tg CO2 y-1 from managed forests, and the uptake of 12.9 (±36%) Tg CO2 y-1 in abandoned lands. This is the first time in Mexico that GHG emissions due to land-use change are presented with national databases and maps, which include levels of uncertainty in all major data sources. Keywords: Diagnosis, Regional/Continental Synthesis

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MCI Synthesis Posters163: Impacts of leaf phenology and water table on interannual variability of region carbon fluxes in mixed landscapes

163: Impacts of leaf phenology and water table on interannual variability of region carbon fluxes in mixed landscapes Ankur R Desai, University of Wisconsin-Madison, desai@aos.wisc.edu (Presenting) D Scott Mackay, State University of New York - Buffalo, dsmackay@buffalo.edu Brent R Helliker, University of Pennsylvania, helliker@sas.upenn.edu Paul R Moorcroft, Harvard University, paul_moorcroft@harvard.edu Attribution of the causes of interannual variability (IAV) in regional CO2 fluxes is a major challenge for the carbon cycle community. While short-term control on regional carbon fluxes are typically well-described by large-scale climate forcing, interannual controls often have indirect climate forcing (e.g., soil moisture deficit, leaf phenology, light quality) and lagged ecosystem responses as the norm rather than the exception. Temporal prediction of regional carbon fluxes will continue to be poor without a better understanding of these mechanisms and their controls on IAV. Site-level ecosystem model calibration at upland and wetland eddy covariance flux tower sites in the upper Midwest USA reveals that leaf phenology, especially in the autumn, appears to be a strong controller of IAV in CO2, due to its control on gross photosynthetic production (GPP). Additionally, for wetlands, ecosystem respiration (ER) is strongly controlled by interannual variability in the dynamics of water table depth. Subboreal landscapes feature intricate upland-lowland landscapes and we expect the responses of both phenology and hydrology to lead to complex patterns in regional IAV. A 10-yr record of regional carbon flux was computed using three independent techniques – a 1-D tall tower boundary layer budget, a forest inventory calibrated demographic ecosystem model, and an eddy covariance flux tower mesonet upscaling. Complex but consistent IAV signals in all three methods appear to be related to variation in both phonological and hydrologic processes. The site-level and regional-level results are being used to calibrate a regional upland-wetland ecosystem model (TREES) to further investigate the mechanisms and prediction of IAV.

Keywords: Attribution, MCI Synthesis 164: Carbon dioxide emissions in fallow periods of a corn-soybean rotation: eddy-covariance versus chamber methods

164: Carbon dioxide emissions in fallow periods of a corn-soybean rotation: eddy-covariance versus chamber methods Guillermo Hernandez-Ramirez, National Soil Tilth Laboratory, guillermo.hernandez@ars.usda.gov Timothy B Parkin, National Soil Tilth Laboratory, tim.parkin@ars.usda.gov Jerry L. Hatfield, National Soil Tilth Laboratory, jerry.hatfield@ars.usda.gov (Presenting) John Prueger, National Soil Tilth Laboratory, john.prueger@ars.usda.gov Tom J Sauer, National Soil Tilth Laboratory, tom.sauer@ars.usda.gov Carbon dioxide (CO2) fluxes at terrestrial surface are typically quantified using eddy-covariance (EC) or chamber (Ch) techniques; however, long-term comparisons of the two techniques are not available. This study was conducted to assess the agreement between EC and Ch techniques when measuring CO2 flux during fallow periods of a corn-soybean rotation. From 2004 to 2007, we quantified CO2 fluxes by both continuous EC and hourly Ch measurements. One flux station and at least two automated soil chambers were permanently deployed in both corn and soybean fields. In November and December, cumulative CO2 efflux by EC method was roughly 1.5-fold greater following corn crop than after soybean (37.1 ± 5.0 vs. 24.8 ± 7.2 g C m-2), whereas the period from January to April showed no differences across crops and years (78 ± 6 g C m-2). This initial difference in the late fall period may be explained by both greater residue production from corn than soybean and fall tillage of the corn field. When contrasting EC to Ch measurements for November and December of 2004, we observed 18% greater cumulative CO2 effluxes with Ch (54.3 vs. 45.9 g C m-2). However, this disagreement was not evenly distributed throughout these two months. The comparison of daily CO2 fluxes by the two techniques revealed episodic patterns of disagreement with 42% (3.5 g C m-2) of the total disagreement concentrated within five consecutive days in late November. This episodic pattern of high disagreement occurred shortly after both the fall tillage operation and an important rainfall event (20 mm d-1). Both unaccounted-for three-dimensional advective CO2 fluxes in EC and soil microclimate modification by Ch may partly explain disagreement between these two techniques. Use of different methods to quantify CO2 fluxes need to be evaluated carefully to understand the spatiotemporal patterns of the differences. Keywords: Site-level Synthesis 165: Spatial Variation of CO2 Fluxes Along Soil Transects in Corn and Soybean Canopies

165: Spatial Variation of CO2 Fluxes Along Soil Transects in Corn and Soybean Canopies Jerry L. Hatfield, USDA-ARS, National Soil Tilth Laboratory, jerry.hatfield@ars.usda.gov (Presenting) Timothy B Parkin, USDA-ARS, National Soil Tilth Laboratory, tim.parkin@ars.usda.gov Tom J Sauer, USDA-ARS, National Soil Tilth Laboratory, tom.sauer@ars.usda.gov John H Prueger, USDA-ARS, National Soil Tilth Laboratory, john.prueger@ars.usda.gov Guillermo Hernandez-Ramirez, USDA-ARS, National Soil Tilth Laboratory, guillermo.hernandez@ars.usda.gov Emission of CO2 from soils is an important component of the C balance in agricultural systems; however, there is little information available on the spatial variation in these fluxes. Development of a more complete understanding of the factors controlling in situ soil respiration requires that the interactions associated with landscape position be assessed. This study was conducted across soils along transects within corn and soybean canopies in the summer of 2007. The study was designed to measure the fluxes from the soil between the rows of the crop and along transects in an area in which the plants had been removed to allow a measurement that would represent soil respiration without

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the confounding effect of root respiration. Measurements were made with a CO2 meter attached to a portable soil chamber (27 cm diameter) at a distance of 5 m between samples. Concurrently, measurements were made of soil water content in the upper 10 cm with a TDR probe, soil temperature with a portable thermometer at a depth of 2 cm, and air temperature at the chamber height. Data were collected weekly from the end of June through the middle of August to encompass a range of soil water contents and plant growth stages. There were differences among days, between cropped and non-cropped transects, and among soils. Average values were different among transects and there were differences in the standard deviations, skewness, and kurtosis for all of the parameters. Analysis of the spatial variation was conducted using geostatistical methods and showed that there was not a consistent trend among days because of soil water differences. Understanding the spatial variation in CO2 emission from soils helps to improve our understanding the dynamics of these processes within fields and improved measurement methods to quantify these values. Keywords: Attribution, MCI Synthesis 166: Modeling the Net Ecosystem Carbon Balance of agroecosystems of the Mid-Continent Intensive campaign region during 2000-2005

166: Modeling the Net Ecosystem Carbon Balance of agroecosystems of the Mid-Continent Intensive campaign region during 2000-2005 Roberto C. Izaurralde, Joint Global Change Research Institute-PNNL, cesar.izaurralde@pnl.gov (Presenting) Allison M. Thomson, Joint Global Change Research Institute-PNNL, allison.thomson@pnl.gov Tris O. West, ORNL, westto@ornl.gov Wilfred M. Post, ORNL, wmp@ornl.gov Jimmy R. Williams, Texas A&M University, williams@brc.tamus.edu David Manowitz, University of Maryland, david.manowitz@gmail.com Daniel R. Chavas, Massachusetts Institute of Technology, drchavas@gmail.com Agroecosystems are dynamic components of the biosphere from the perspective of the carbon (C) balance because of the influence of human management on the a) size and fate of net primary productivity, b) size and longevity of the soil C pool, and c) lateral transfers and fate of C due to erosion and deposition. This work uses the EPIC (Environment Policy Integrated Climate) model to simulate the Net Ecosystem Carbon Balance (NECB) in the Mid-Continent Intensive campaign region during 2000-2005. EPIC simulates NECB as the difference between C additions (surface and subsurface litter, organic amendments) and C losses (harvest, soil respiration, soil erosion, and leaching). The spatial modeling units are selected to capture the climate, soil, and management variability at the 8-digit hydrologic unit watershed scale. Modeled soils account for ~70% of the variability in soil C. Each watershed is assigned a major cropping system based on National Resource Inventory data. Daily precipitation, temperature, solar radiation, relative humidity, and wind speed data needed to run EPIC during 2000-2005 were extracted from the NCAR Reanalysis database. NECB results are presented at the county scale for comparisons with results of atmospheric inversions. Keywords: Diagnosis, MCI Synthesis 167: Simulation of carbon fluxes and prediction of crop yields within MCI region using SiBcrop

167: Simulation of carbon fluxes and prediction of crop yields within MCI region using SiBcrop Erandathie Lokupitiya, Dept. of Atmospheric Science, Colorado State University, erandi@atmos.colostate.edu (Presenting) Scott Denning, Dept. of Atmospheric Science, Colorado State University, denning@atmos.colostate.edu Keith Paustian, Natural Resource Ecology Laboratory, Colorado State University, keithp@nrel.colostate.edu Kathy Corbin, CSIRO, Australia, kdcorbin@atmos.colostate.edu Ian Baker, Dept. of Atmospheric Science, Colorado State University, baker@atmos.colostate.edu Kevin Shaefer, National Snow and Ice Data Center, University of Colorado, Boulder, kevin.schaefer@nsidc.org Matt Hansen, South Dakota State University, Matthew.Hansen@sdstate.edu Kyle Pittman, South Dakota State University, Kyle.Pittman@sdstate.edu Simple Biosphere Model (SiB) has been used to predict fine (both temporal and spatial) resolution carbon and other land-atmosphere exchanges from a variety of ecosystems. SiBcrop, a model especially developed for croplands by incorporating crop-specific phenology and physiology within SiB, was used to predict carbon fluxes from corn, soybean, and wheat croplands in the US mid west. The performance of SiBcrop has been evaluated by testing it against the site specific observed data at several Ameriflux eddy covariance flux tower sites with a variety of crops. SiBcrop has been coupled with the regional Atmospheric Modeling System (RAMS, a model developed at Colorado State University) for predicting regional scale carbon and other fluxes. In this study, we used high resolution (1km) crop maps for soybean, corn, and wheat crops in the mid continental intensive (MCI) region under the North American Carbon program, to predict crop yields in the region. The crop maps of 1km resolution were created by processing the state level 56 m resolution AWiFS crop images produced by the cropland datalayer of the National Agricultural Statistics Service (NASS). The biomass carbon output from the model was converted to crop yields considering the fraction of carbon in biomass, percent moisture, and specific unit conversions relevant to standard crop yields reported by NASS. Finally, the yields predicted from the model were compared against the county-level crop yields reported by NASS for the counties in the MCI region. Keywords: Diagnosis, Attribution, Prediction, Site-level Synthesis, MCI Synthesis 168: Observations and modeling results of regional-scale CO2 mixing ratio during the NACP’s MidContinent Intensive

168: Observations and modeling results of regional-scale CO2 mixing ratio during the NACP’s MidContinent Intensive Natasha Miles, Penn State Univ, nmiles@met.psu.edu (Presenting) Scott Richardson, Penn State Univ, srichardson@psu.edu (Presenting) Kathy Corbin, Colorado State Univ, kdcorbin@atmos.colostate.edu Ian Baker, Colorado State Univ, baker@atmos.colostate.edu Eric Crosson, Picarro, Inc., eric@picarro.com Kenneth J. Davis, Penn State Univ, davis@met.psu.edu Scott Denning, Colorado State Univ, denning@atmos.colostate.edu The NACP’s MidContinental Intensive (MCI) sponsored a regional network of five atmospheric CO2 measurement sites on roughly a 500-km

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diameter ring centered on Iowa during April 2007 – October 2008, as well as modeling efforts to estimate the CO2 flux and concentration. The daily daytime average throughout the 2007 and 2008 growing seasons indicated a 50-ppm seasonal drawdown, with significant synoptic variability. The drawdown in this largely agricultural region (heavily influenced by corn) is significantly larger than the 20–30 ppm typically seen in forested regions. The CO2 mixing ratio at the sites nearly always differs by more than 5 ppm, while at times the inter-site difference is as large as 30–50 ppm. While variability in the regional spatial gradients is expected because of synoptic changes and differing source regions, the magnitude observed is surprisingly large given the sites’ relative proximity. This has important implications for the design of regional and perhaps continental observing systems. Modeling efforts attempted to evaluate the cause of the observed large and variable gradients, and to test the coupled model’s ability to reproduce these gradients. We simulated both CO2 fluxes and concentrations for June through August 2007 using the coupled ecosystem-atmosphere model SiB3-RAMS, focusing on the concentrations over the MCI region. To improve CO2 fluxes in this region, we coupled a crop phenology model to SiB3-RAMS, which calculates the leaf area index (LAI), fraction of photosynthetically active radiation absorbed by the plants (FPAR), and net ecosystem exchange (NEE) for corn, soybeans, and wheat. Including the crop model dramatically improved the concentrations at all the towers, reducing the root mean square errors by nearly half. The model simulation suggested that large changes in the CO2 differences between the towers during the 2007 growing season were due to a large-scale gradient between high concentrations to the south of the MCI region and low concentrations to the north.

Keywords: Diagnosis, MCI Synthesis 169: Soil Carbon Budget over the U.S. Midwest Cropland

169: Soil Carbon Budget over the U.S. Midwest Cropland Zaitao Pan, St. Louis Unifersity, panz@eas.slu.edu (Presenting) Eugene S. Takle, Iowa State University, gstakle@iastate.edu Moti Segal, Iowa State University, segal@iastate.edu David Andrade, St. Louis University, andraded@eas.slu.edu The projected climate change is likely to alter CO2 flux at the surface by increasing both biomass productivity (photosynthesis) and soil respiration. The magnitude and sign of the net CO2 flux are reflected by changes in size of soil carbon pools. In this project, we use the DayCENT model, a variant of CENTURY model with a daily time step, driven by past climate and IPCC AR4 scenario climates to project the trends of soil organic carbon (SOC) pools for the Midwest cropland under various management strategies. The B1, A1b, and A2 scenario climates from three GCMs representing respectively cold/wet, normal, and warm/dry models were selected for three time windows: 1961-2000, 2046-2065, and 2081-2100. Despite differences among the models, the three GCMs projected growing season (May-September) warming by 1.5-1.8C around the mid-21st century under the low emission B1 scenario. The moderate-high emission A2 scenario produced an additional 1C warming than the B1 scenario. The balanced A1b scenario predicted a climate that is about 0.2C colder than the A2 scenario. Future precipitation amounts during the growing season increase by 10-30% depending on individual models and scenarios. Under all these scenario climates, DayCENT simulations predict a 10-30% decline in SOC within the top 20 cm of soil profile by mid-century if a conventional tillage sachem is adopted. No-till practice combined with appropriate crop rotations and harvest methods can increase SOC by up to 20%, thereby reversing the trend of decline. The simulated SOC differences among the scenarios vary within 8% of each other, smaller than the inter-model range of 28%, underlining the uncertainty attributable to individual GCM models. Further diagnoses indicate that the SOC decline is more (less) due to heterotrophic soil respiration (NPP), suggesting the dominance of warming effects on soil microbial decomposition. Keywords: Diagnosis, Prediction, Decision Support, Regional/Continental Synthesis 170: Dynamics of below canopy nighttime CO2 profile measurements for corn and soybean

170: Dynamics of below canopy nighttime CO2 profile measurements for corn and soybean John H Prueger, USAD-ARS-NSTL, john.prueger@ars.usda.gov (Presenting) Timothy B Parkin, USAD-ARS-NSTL, tim.parkin@ars.usda.gov Jerry L. Hatfield, USAD-ARS-NSTL, jerry.hatfield@ars.usda.gov Tom J Sauer, USAD-ARS-NSTL, tom.sauer@ars.usda.gov Guillermo Hernandez-Ramirez, USAD-ARS-NSTL, guillermo.hernandez@ars.usda.gov Tagir G Gilmanov, South Dakota State University, tagir.gilmanov@sdstate.edu Nighttime respiration from soil and vegetation sources represents an important component of the carbon cycle for agricultural systems. Indeed, accurate measurement and interpretation of respiration processes remain challenging and are critical to accurately estimate Net Ecosystem Production (NEP) in spatially large agricultural ecosystems such as the Upper Midwest region. This study uses data acquired in 2007 and 2008 from an ongoing multi-year study of surface energy and mass balance exchange from two fields in central Iowa that are representative of typical agricultural production practices in the Upper Midwest for corn and soybeans. Instrumentation includes the complete surface energy and mass balance (net radiation, soil heat flux, latent and sensible heat fluxes and carbon dioxide fluxes) for both fields. Additionally, automated soil chambers and below canopy profile measurements of water vapor and carbon dioxide for each field provide hourly measurements of heterotrophic and autotrophic respiration to complement the ongoing monitoring effort. Thus we have the data to evaluate the major components of carbon dioxide exchange but will focus on below canopy profile concentrations of carbon dioxide during the nighttime. These concentrations can and will vary as functions of canopy density, soil (type, temperature, water content) and surface layer micrometeorological conditions. We will show how the range of fluctuations in temperature, turbulence and soil conditions influence dynamic and often rapid changes in respiration in the below canopy air space. During certain nighttime conditions respiration processes can indeed contribute to significant underestimation of NEP. Keywords: Attribution, Site-level Synthesis, MCI Synthesis 171: Uncertainty in Modeled Agricultural C Stock Changes in the Mid-Continent Region

171: Uncertainty in Modeled Agricultural C Stock Changes in the Mid-Continent Region

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Shannon L Spencer, Natural Resource Ecology Laboratory, Colorado State University, shannon.spencer@colostate.edu (Presenting) Stephen Ogle, Natural Resource Ecology Laboratory, Colorado State University, ogle@nrel.colostate.edu Management can have a significant influence on C stock changes in agricultural land, by changing net primary productivity and incorporation of C into soils, as well as decomposition of soil organic carbon. Yet, estimates of carbon stock changes are often based on simulation modeling and have large uncertainties. To reduce those uncertainties, soil measurements from a monitoring network are being combined with simulation modeling and remote sensing data to improve estimation of NPP. Specifically, initial samples of soil carbon were collected from 45 row-crop sites in the Mid-Continent Region between 2006 and 2007. These sites are modeled using an integrated CASA-Century modeling framework developed specifically for agricultural lands, and relying on 250m MODIS EVI data to drive the NPP estimation. A statistical modeling procedure is used to estimate uncertainty from the comparison of measurements versus modeled estimates. The Century-CASA model and resulting uncertainty estimator are applied to agricultural sites that are part of the USDA National Resources Inventory within the Mid-Continent Region to estimate regional C stock changes and associated uncertainties. Using measurements from a monitoring network and remote sensing data is expected to greatly improve estimates of regional and national C stock changes for agricultural lands, and better inform public policy. Keywords: MCI Synthesis

non-CO2 Synthesis Posters172: Constraining the Terrestrial Carbon Cycle with Atmospheric Measurements of Carbonyl Sulfide (OCS)

172: Constraining the Terrestrial Carbon Cycle with Atmospheric Measurements of Carbonyl Sulfide (OCS) Joseph A Berry, Carnegie Institution for Science, jberry@ciw.edu Stephen A Montzka, NOAA/ESRL/GMD, stephen.a.montzka@noaa.gov J Elliott Campbell, College of Engineering University of California, Merced, ecampbell3@ucmerced.edu (Presenting) S Randolph Kawa, NASA GSFC Code 613.3, kawa@maia.gsfc.nasa.gov Ian Baker, Department of Atmos. Sci., Colorado State University, baker@atmos.colostate.edu A Scott Denning, epartment of Atmos. Sci., Colorado State University, denning@atmos.colostate.edu Sheri Conner- Gausephol, epartment of Atmos. Sci., Colorado State University, sheri@atmos.colostate.edu Adam Wolf, Carnegie Institution for Science, adamwolf@stanford.edu Carbonly sulfide (OCS), an analog of carbon dioxide, is emerging as a useful atmospheric tracer of the terrestrial carbon cycle. GC-MS analysis of flask samples and IR absorption spectroscopy are used to measure OCS concentration in the atmosphere. The atmospheric lifetime and seasonal pattern of change in OCS concentration are similar to those of CO2. Oxidation of sulfur compounds produced in the oceans is the source of about 90% of the OCS to the atmosphere with biomass burning and industrial processes providing the remaining 10%. The principal sink for OCS is uptake by leaves and soils. The rate of uptake by leaves is closely linked to the rate of CO2 uptake in gross primary production (GPP), and in soils, OCS is consumed by microbial activity linked to decomposion of organic matter. We have incorporated the biochemical and biophysical mechanisms controlling OCS exchange into a land surface/terrestrial carbon cycle model (SIB), and we have used this model to simulate global OCS and CO2 fluxes and transported these together with other known sources and sinks in a chemical transport model (PCTM). The system of models shows good skill in reproducing the seasonal cycle of OCS concentration at 13 background atmospheric stations sampled by NOAA. We show that vertical profiles of OCS and CO2 measured by INTEX-NA, NOAA-ESRL and TC4 are consistent with the modeled surface fluxes and atmospheric transport. These simultaneous mesasurements of OCS and CO2 have been inverted to obtain information on the rates of photosynthesis and respiration over the North American mid-continent. We argue that support for expanded atmospheric sampling of OCS, and for studies leading to an improved understanding OCS exchange by land and ocean processes, could yield significant improvements in our understanding of the carbon cycle at the ecosystem, regional and global scales. Keywords: Diagnosis, Regional/Continental Synthesis, non-CO2 Greenhouse Gases Synthesis 173: Seasonal Variations in Methane Emissions from Central California

173: Seasonal Variations in Methane Emissions from Central California Chuanfeng Zhao, Lawrence Berkeley National Lab, CZhao@lbl.gov Arlyn E. Andrews, NOAA-Earth Science Research Laboratory, Arlyn.Andrews@noaa.gov Janusz Eluszkiewicz, Atmospheric Environmental Res. Inc., jeluszki@aer.com Adam I. Hirsch, NOAA-Earth Science Research Laboratory, Adam.Hirsch@noaa.gov Clinton MacDonald, Sonoma Technologies Inc., Clint@sonomatech.com Thomas Nehrkorn, Atmospheric Environmental Res. Inc., tnehrkor@aer.com Marc L. Fischer, Lawrence Berkeley National Lab, MLFischer@lbl.gov (Presenting) A time series comprising nearly one year of CH4 mixing ratio measurements were obtained from tall-towers in Central California. The measurements are applied in an inverse model to estimate regional seasonal variations in surface emissions of CH4 in Central California. Simulated CH4 mixing ratios are calculated based on spatially resolved annual average a priori CH4 emission estimates and simulated atmospheric transport. Atmospheric transport and surface influences (footprints) are computed using the Weather Research and Forecast (WRF) model coupled to the Stochastic Time-Inverted Lagrangia Transport (STILT) model (WRF-STILT). Initial analysis of the Oct.-Dec., 2007 period show that geometric linear regressions of modeled and measured CH4 mixing ratios yield slopes of 0.84 ± 0.12 and 0.92 ± 0.1 for the October-December, 2007 period using California specific and Edgar 3.2 emission maps respectively, suggesting that actual CH4 emissions were 10 to15% higher than the inventory estimates. A Baysian analysis of the October-December period obtains posterior scaling factors for CH4 from different source sectors, suggesting that livestock emissions are higher than a priori estimates. Using the first year of data (Oct., 2007 – Sept, 2008) we estimate the seasonal variations in total emissions and changes in relative contributions from different source sectors.

Keywords: Diagnosis, Attribution, Regional/Continental Synthesis, non-CO2 Greenhouse Gases Synthesis

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174: Soil methane and nitrous oxide dynamics as influenced by tillage and fertilizer management practices

174: Soil methane and nitrous oxide dynamics as influenced by tillage and fertilizer management practices Ermson Z. Nyakatawa, Alabama A&M University, ermson.nyakatawa@aamu.edu (Presenting) David A. Mays, Alabama A&M University, docmays@comcast.net Tom Way, USDA/ARS, thomas.way@ars.usda.gov Dexter Watts, USDA/ARS, dexter.watts@ars.usda.gov David Smith, USDA/ARS, david.smith@ars.usda.gov Allen Torbert, USDA/ARS, allen.torbert@ars.usda.gov Land application of organic and inorganic fertilizers can significantly contribute to the enrichment of the atmosphere with greenhouse gases such as methane (CH4) and nitrous oxide (N2O). This paper discusses emissions of CH4 and N2O from an agricultural soil receiving poultry manure (PM) and ammonium nitrate (AN) inorganic fertilizer in conventional tillage (CT) and no-till (NT) systems using surface (SA), soil incorporation (SI), or band (BA) fertilizer application methods, on a Decatur silt loam soil under corn (Zea mays L.) production in north Alabama. Soil gas samples were collected from the field using the static chamber method and analyzed for CH4 and N2O concentrations using a Varian CP-3800. NET soil CH4 fluxes in plots which received 150 kg Nha-1 in the form of poultry manure in NT system using surface application method (NT-PM-SA) and in plots which received 150 kg Nha-1 in the form of AN in CT system using soil incorporation application method (CT-AN-SI) were 3.6 and 5.1 µg m-2 s-1, respectively, during spring and summer of 2008. Soils under the other treatments including a grass fallow control were net sinks of atmospheric CH4. The highest NET soil N2O fluxes were observed in plots which received 150 kg Nha-1 in the form of PM in NT system using BA method (NT-PM-BA) (184.6 µg m-2 s-1), followed by plots which received the CT-AN-SI treatment (46.7 µg m-2 s-1) and then in plots which received 150 kg Nha-1 AN in CT system using surface application (CT-AN-SA) treatment (37.7 µg m-2 s-1). Our results so far suggests that among the treatments being studied, application of PM in NT system using surface or band application methods and application of AN in CT system using surface or soil incorporation methods have the greatest potential to supply CH4 and N2O greenhouse gases to the environment. Keywords: Diagnosis, Attribution, Site-level Synthesis, non-CO2 Greenhouse Gases Synthesis 175: Spatial and temporal patterns of CH4 and N2O fluxes between the atmosphere and terrestrial ecosystems over North America

175: Spatial and temporal patterns of CH4 and N2O fluxes between the atmosphere and terrestrial ecosystems over North America Hanqin Tian, Auburn University, tianhan@auburn.edu (Presenting) Xiaofeng Xu, Auburn University, xuxiaof@auburn.edu Guangsheng Chen, Auburn University, chengu1@auburn.edu Mingliang Liu, Auburn University, liuming@auburn.edu Chaoqun Lu, Auburn University, czl0003@auburn.edu Wei Ren, Auburn University, renwei1@auburn.edu Chi Zhang, Auburn University, zhangch@auburn.edu The spatial and temporal patterns of CH4 and N2O fluxes between the atmosphere and terrestrial ecosystems over North America are far from certain. In this study, we have used the Dynamic Land Ecosystem Model (DLEM) driven by natural and anthropogenic forces to quantify the magnitude and patterns of CH4 and N2O fluxes over North America for the time period from 1979 to 2005. By using a number of simulation experiments, we also quantify the relative contribution of climate variability, land-cover/land use change, atmospheric composition (carbon dioxide and tropospheric ozone) and precipitation chemistry (nitrogen composition) to the magnitude and patterns of CH4 and N2O fluxes for the same period. Our preliminary results show that temperature and precipitation are primary controls over seasonal and interannual variations in CH4 and N2O fluxes over North America. Nitrogen deposition and fertilization have resulted in a significant increase in N2O emission from land ecosystems. Keywords: Diagnosis, Attribution, non-CO2 Greenhouse Gases Synthesis 176: Methane and carbon monoxide budgets for the Los Angeles area from September 2007 through June 2008.

176: Methane and carbon monoxide budgets for the Los Angeles area from September 2007 through June 2008. Debra Wunch, California Institute of Technology, dwunch@caltech.edu (Presenting) Paul O Wennberg, California Institute of Technology, wennberg@caltech.edu Geoffrey C Toon, Jet Propulsion Laboratory, geoffrey.c.toon@jpl.nasa.gov Gretchen Keppel-Aleks, California Institute of Technology, gka@gps.caltech.edu Yael G Yavin, None, ygyavin@gmail.com We will present an urban budget of methane, carbon dioxide and carbon monoxide, from nearly a year's worth of solar absorption measurements in Pasadena, a suburb of Los Angeles, California. The data were recorded by a high-resolution Fourier transform spectrometer that is part of the Total Carbon Column Observing Network (TCCON). Pasadena is a polluted urban site, and these high-precision measurements point to significant urban sources of methane. We will discuss the implications of these urban methane sources to the regional methane budget. Keywords: non-CO2 Greenhouse Gases Synthesis

Coastal Synthesis Posters 177: Seasonal evolution of carbon sources and sinks along the western continental margin of North America

177: Seasonal evolution of carbon sources and sinks along the western continental margin of North America

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Simone Alin, PMEL/NOAA, Simone.R.Alin@noaa.gov (Presenting) Burke Hales, Oregon State University, bhales@coas.oregonstate.edu Peter Strutton, Oregon State University, strutton@coas.oregonstate.edu Previously, we have applied the artificial neuronal network approach of Saraceno et al. (2006) to objectively define biogeochemical regions along the west coast of North America from British Columbia through Central America. Remotely sensed annual climatologies of sea surface temperature (SST), chlorophyll, and wind stress data comprised the inputs used to delineate biogeochemical regions. The resulting “self-organizing map” (SOM) represents a division of the west coast into static biogeochemical regions based on long-term average conditions. Based on this SOM, it is clear that biogeochemical regions along the west coast of North America are controlled by factors that vary with both latitude and distance offshore. Within each region of the SOM, pCO2 data collected across years can be fit with property-property relationships relating pCO2 with environmental controlling variables, including the remotely sensed data, spatial information (latitude, longitude), and seasonality. The result yields a mechanistic prediction algorithm capable of extrapolating CO2 concentrations and fluxes across space and through time. Here, we extend this approach to examine temporal changes in the construction of the SOM along the western continental margin of North America. That is, rather than using annual climatologies of satellite data for inputs to the SOM, we use seasonal and monthly climatologies, resulting in satellite-based CO2 algorithms that are tuned not only in space but also in time. By better accommodating the spatial and temporal variability in the system, we can improve the satellite-based estimates of pCO2, and refine our understanding of the drivers of CO2 fluxes along continental margins. Keywords: Diagnosis, Attribution, Coastal Synthesis 178: Is Lake Superior a net carbon source or sink?

178: Is Lake Superior a net carbon source or sink? Nazan Atilla, UW-Madison, atilla@wisc.edu (Presenting) Galen A. McKinley, UW-Madison, gamckinley@wisc.edu Valerie Bennington, UW-Madison, benesh@wisc.edu Noel Urban, Michigan Technological University, nurban@mtu.edu Nobuaki Kimura, UW-Madison, nkimura3@wisc.edu Chin Wu, UW-Madison, chinwu@engr.wisc.edu Ankur Desai, UW-Madison, desai@aos.wisc.edu Carbon fluxes from large water bodies may be important to understanding regional and continental carbon budgets (Alin et al. 2007; Cole and Caraco, 1998). However, because these fluxes are poorly known, terrestrial carbon scaling techniques and models typically ignore carbon fluxes between the water and the atmosphere. With a surface area that comprises 3% of the continental United States, the Laurentian Great Lakes may play an important role in the continental carbon budget, and should be even more important to the mid-continent region. We examine mechanisms of carbon fluxes from Lake Superior at small and large spatial and temporal scales using available data. In the western arm, we consider the relationship between temperature, biological activity and pCO2 at various time scales during the summer of 2001. We find that springtime pCO2 is determined predominantly by temperature, but after the Lake warms and stratifies, biological activity can draw down CO2 and rapidly and decrease near-surface pCO2. The magnitude of the air-lake flux is considered using a reanalysis of biannual lake-wide surveys and is coupled with an assessment of our current understanding of terrestrial carbon inputs. We link our analysis to a coupled physical-biogeochemical model of the Lake to improve our understanding of the lake carbon budget and its spatial and temporal variability, and to quantitatively improve the carbon budget. Keywords: Diagnosis, Attribution, Site-level Synthesis, Regional/Continental Synthesis, Coastal Synthesis 179: Land to ocean carbon coupling between the Penobscot watershed and Gulf of Maine

179: Land to ocean carbon coupling between the Penobscot watershed and Gulf of Maine William M Balch, Bigelow Laboratory for Ocean Sciences, bbalch@bigelow.org (Presenting) George Aiken, USGS, Boulder Co, graiken@usgs.gov Andrew Barnard, WET Labs, Philomath, OR, andrew@wetlabs.com Thomas Huntington, USGS Augusta, ME, thunting@usgs.gov Christina Orrico, WET Labs, Philomath, OR, cris@wetlabs.com Collin Roesler, Darling Center, Univ. Maine, Walpole, ME, Collin.Roesler@maine.edu Huije Xue, Univ. Maine, Orino, ME, hxue@maine.edu We will describe recent efforts to document the nature (timing and flux) of carbon from the Penobscot watershed, one of Maine’s largest watersheds. We will follow the carbon down the Penobscot River into Penobscot Bay, and ultimately into the Gulf of Maine. In this talk, we will highlight the nature of the carbon flux (particulate versus dissolved), and recent major flux events associated with precipitation maxima. Optical proxies for tracking DOC will be evaluated as well as nonlinear changes in DOC associated with microbial and physical processes, as the material mixes down the salinity gradient. Recent isotope-derived ages of DOC will be used to understand turnover times of the different dissolved carbon pools. Results from this work have been incorporated into models to estimate the total flux of dissolved organic carbon from the watershed over time. Finally, we will show results of a decadel time series that document both riverine and marine sources of dissolved organic carbon in the Gulf of Maine. Keywords: Coastal Synthesis 180: Carbon Fluxes in the Gulf of Mexico – A report on the Ocean Carbon and Biogeochemistry Scoping Workshop on Terrestrial and Coastal Carbon Fluxes in the Gulf of Mexico; St. Petersburg, Florida, May 6-8, 2008

180: Carbon Fluxes in the Gulf of Mexico – A report on the Ocean Carbon and Biogeochemistry Scoping Workshop on Terrestrial and Coastal Carbon Fluxes in the Gulf of Mexico; St. Petersburg, Florida, May 6-8, 2008 Paula Coble, College of Marine Science, University of South Florida, pcoble@marine.usf.edu (Presenting) Lisa Robbins, Center for Coastal and Watershed Studies, U.S. Geological Survey, lrobbins@usgs.gov A major source of North American and global uncertainty is the Gulf of Mexico (GMx), a large semi-enclosed subtropical basin bordered by the

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United States, Mexico, and Cuba. Like many of the marginal oceans world wide, the GMx remains largely unsampled and poorly characterized in terms of its air:sea exchange of carbon dioxide and other carbon fluxes. Approximately 90 participants from 23 states and Mexico participated in a 2 ½ day workshop to develop research strategies to address the information gaps of carbon fluxes associated with the Gulf of Mexico. The Ocean Carbon and Biogeochemistry program (OCB; http://www.us-ocb.org/OCB) sponsored this workshop with support from U.S. National Science Foundation, National Oceanic and Atmospheric Administration, NASA, U.S. Geological Survey, and the University of South Florida. The goal of the workshop was to bring together researchers from across multiple disciplines- from terrestrial and aquatic to marine ecosystems- to discuss state of knowledge in Gulf of Mexico carbon fluxes, data gaps and overarching questions in the Gulf of Mexico System. The discussions at the workshop were intended to stimulate integrated studies of marine and terrestrial biogeochemical cycles and associated ecosystems that would help to establish the evolving role of the Gulf of Mexico in the carbon cycle, in the face of environmental change. The Gulf of Mexico needs to be studied as a system that includes watersheds, margins, open Gulf of Mexico, overlying atmosphere, and underlying sediments. Participants recognized that the key to understanding the GMx system required an international collaboration with scientists from countries adjacent to the GMx. Improved collaboration across existing research community boundaries is also critical and should be encouraged by funding agencies. This paper will report on the outcomes from the workshop, which included a summary of the state of knowledge on carbon dynamics within the Gulf of Mexico system, formulation of questions that will drive future research projects, recommendations on the infrastructure required to study the carbon fluxes and the modeling framework for the integration across the system, and how best for the community to move forward in designing research programs to address the important questions. Keywords: Coastal Synthesis 181: Riverine DOC Fluxes from the Northern Coastal Temperate Rainforest

181: Riverine DOC Fluxes from the Northern Coastal Temperate Rainforest Rick Edwards, PNW Research Station, US Forest Service, rtedwards@fs.fed.us (Presenting) Dave D'Amore, PNW Research Station, US Forest Service, ddamore@fs.fed.us Eran Hood, Universtiy Of Alaska Southeast, ewhood@uas.alaska.edu Frances Biles, PNW Research Station, US Forest Service, fbiles@fs.fed.us The Tongass National Forest (Tongass) is the largest national forest in the United States and contains most of the remaining unmodified Coastal Temperate Rainforest (CTR) in North America. The Tongass covers 68,748 km2 of southeast Alaska with 42,000 km of coastline. Annual rainfall averages 2.9 meters. The Tongass contains about 7% of the carbon stored in forests in the United States and 90% of the Tongass lies within 5 km of saltwater, creating a high potential for terrestrial influence on the near-shore environment. Riverine carbon from the Tongass flows into a web of estuaries and channels within the Alexander Archipelago where some is metabolized and some enters long term storage. In contrast to riverine inputs to the open ocean, Tongass carbon is likely retained near the coastline for longer duration and may exert a larger influence on coastal productivity. Combining a regional survey of riverine DOC concentrations with estimates of climatic and hydrologic factors we estimated the present DOC flux from the Tongass and extrapolated rates to similar CTR forest in Canada and the US. The preliminary flux estimate yields an annual runoff of 0.8 teragrams DOC y-1 from the Tongass. DOC flux per unit area is one of the largest reported (11.9 megagrams km2 y-1). Extrapolating to similar forests stretching from British Columbia to coastal western Alaska gives a total DOC flux of 1.5 teragrams of DOC y-1. In contrast, the Yukon River, which is about 6.5x larger than the CTR exports about one third as much DOC and has 1/10 the export per unit watershed area. These CTR flux estimates are conservative in that they do not include fluxes from large continental rivers draining inland Canada and Alaska. Impacts of climate change on CTR carbon fluxes are unknown, but increased temperatures could result in even higher losses of soil carbon.

Keywords: Diagnosis, Site-level Synthesis, Regional/Continental Synthesis, Coastal Synthesis 182: Carbon Cycle Simulations for the East Coast Continental Shelf of North America

182: Carbon Cycle Simulations for the East Coast Continental Shelf of North America Katja Fennel, Dalhousie University, katja.fennel@dal.ca (Presenting) Michael Previdi, Lamont-Doherty Earth Observatory, mprevidi@ldeo.columbia.edu John Wilkin, Rutgers University, wilkin@marine.rutgers.edu Raymond Najjar, Pennsylvania State University, najjar@essc.psu.edu We are presenting results from a nested physical-biogeochemical ocean model for the North American East Coast continental shelf and adjacent deep ocean that includes organic and inorganic carbon species and describes physical and biogeochemical processes driving air-sea exchange of CO2. Our presentation is aimed at illustrating (1) the importance of biogeochemical constraints on coastal carbon fluxes and their global relevance, (2) the challenges posed by temporal and spatial variability, and (3) the utility of nesting approaches for future inclusion of continental margin processes in global Earth System Models. Specifically, we are focusing on the biogeochemical constraints on carbon fluxes imposed by the nitrogen cycle and on interannual variability. Model simulations are critically evaluated in comparisons with available in situ and remote sensing data sets. Keywords: Diagnosis, Prediction, Coastal Synthesis 183: U.S. Eastern Continental Shelf Carbon Cycling (USECoS): Modeling, Data Assimilation and Analysis

183: U.S. Eastern Continental Shelf Carbon Cycling (USECoS): Modeling, Data Assimilation and Analysis Marjorie Friedrichs, Virginia Institute of Marine Science, marjy@vims.edu (Presenting) Eileen Hofmann, Old Dominion University, hofmann@ccpo.odu.edu Bronwyn Cahill, Rutgers University, bronwyn@marine.rutgers.edu Katja Fennel, Dalhousie University, katja.fennel@dal.ca Dale Haidvogel, Rutgers University, dale@marine.rutgers.edu Kimberly Hyde, NOAA/NMFS Narragansett Lab, kimberly.hyde@noaa.gov

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Cindy Lee, Stony Brook University, cindylee@notes.cc.sunysb.edu Antonio Mannino, NASA Goddard Space Flight Center, antonio.mannino@nasa.gov Charles McClain, NASA Goddard Space Flight Center, charles.r.mcclain@nasa.gov Ray Najjar, Pennsylvania State University, najjar@meteo.psu.edu John O'Reilly, NOAA/NMFS Narragansett Lab, joreilly@mola.na.nmfs.gov David Pollard, Pennsylvania State University, pollard@essc.psu.edu Sergio Signorini, NASA Goddard Space Flight Center, sergio.signorini@nasa.gov John Wilkin, Rutgers University, wilkin@marine.rutgers.edu Jianhong Xue, Virginia Institute of Marine Science, jxue@vims.edu Although the oceans play a major role in the uptake of fossil fuel CO2 from the atmosphere, there is much debate about the contribution from continental shelves, because many key shelf fluxes are not yet well quantified: the exchange of carbon across the land-ocean and shelf-slope interfaces, air-sea exchange of CO2, burial, and biological processes including productivity. The goal of the USECoS (U.S. Eastern Continental Shelf Carbon Cycling) project is to quantify these carbon fluxes along the eastern U.S. coast using models quantitatively evaluated by comparisons with observations, and to establish a framework for predicting how these fluxes may be modified as a result of climate and land use change. This study builds on results from our earlier NASA-funded study of carbon cycling, which resulted in development of a coupled biogeochemical-ocean circulation model configured for the U.S. eastern continental shelf. This model was extensively evaluated with in situ and remotely-sensed data. Results indicated that reduction in uncertainties in the shelf component of the global carbon cycle required 1) increased resolution of the physical model via nesting, 2) refinements to the biogeochemical model and 3) quantitatively evaluating these via assimilation of biogeochemical data (in situ and remotely-sensed). These model improvements will be described and the consequences of these for simulation of carbon cycling on the U.S. east coast continental shelf discussed. The resultant model provides a framework for better understanding and reducing estimates of uncertainties in current and future carbon transformations and cycling in continental shelf systems. Keywords: Diagnosis, Attribution, Coastal Synthesis 184: Advection of Salty low-Oxygen, low-pH Water onto the Continental Shelf from Baja California Mexico to San Luis Obispo EUA

184: Advection of Salty low-Oxygen, low-pH Water onto the Continental Shelf from Baja California Mexico to San Luis Obispo EUA Jose Martin Hernandez, Instituto de InvestigacionesOceanologicas. Universidad autonoma de Baja California, jmartin@uabc.mx (Presenting) Richard A. Feely, NOAA/PML, richard.a.feely@noaa.gov Chirstopher L. Sabine, NOAA/PML, chris.sabine@noaa.gov Debby Ianson, Fisheries and Oceans Canada, Institute of Ocean Science, iansond@pac.dfo-mpo.gc.ca Burke Hales, College of Oceanic & Atmospheric Sciences, Oregon State University, bhales@coas.oregonstate.edu During a cruise in May-June 2007 onboard the Research Ship Wecoma, we observed saltier, low oxygen, low pH water coming from the tropical Pacific observed from San Gregorio Baja California, Mexico to San Luis Obispo CA EUA. In Baja California the temperature and salinity data were considered anomalous when is compared with the climatological database. Water with oxygen concentrations lower than 150 µM was also corrosive with respect to aragonite (pH <7.8) and saltier, ranging between 34.5 and 34. This water mass reached mid-shelf depths (>40m) from the south at approximately 40 km from the coast. The lowest oxygen concentrations were detected in San Gregorio Baja California with values below 10 µM, but also with the more corrosive water (Ωarag between 0.9 to 0.7). Under this condition the duo feature low oxygen-corrosive water can seriously impact the development of many marine organisms in this region Keywords: Regional/Continental Synthesis, Coastal Synthesis 185: A biogeochemical/ecological model applied to the California Current System

185: A biogeochemical/ecological model applied to the California Current System Xin Jin, Joint Institute for Regional Earth System Science and Engineering (JIFRESSE), UCLA,, xjin@ucla.edu (Presenting) Nicolas Gruber, Institute of Biogeochemistry and Pollution Dynamics, ETH Zurich, nicolas.gruber@env.ethz.ch Curtis Deutsch, Dept. of Atmospheric and Oceanic Sciences, UCLA, cdeutsch@atmos.ucla.edu Hartmut Frenzel, Dept. of Atmospheric and Oceanic Sciences, UCLA, hfrenzel@ucla.edu Scott C. Doney, Marine Chemistry and Geochemistry Department, WHOI, sdoney@whoi.edu Zouhair Lachkar, Institute of Biogeochemistry and Pollution Dynamics, ETH Zurich, zouhair.lachkar@env.ethz.ch Damian Loher, Institute of Biogeochemistry and Pollution Dynamics, ETH Zurich, damian.loher@env.ethz.ch James C. McWilliams, Institute of Geophysics and Planetary Physics, UCLA, jcm@atmos.ucla.edu Takeyoshi Nagai, Dept. of Ocean Sciences, Tokyo University of Marine Science and Technology, tnagai@kaiyodai.ac.jp Gian-Kasper Plattner, Institute of Biogeochemistry and Pollution Dynamics, ETH Zurich, gian-kasper.plattner@env.ethz.ch The carbon cycle along the continental margins has been recognized as an important component of the global carbon cycle. The continental margins can impact the oceanic carbon cycle and ultimately atmospheric CO2 in two ways. The first pathway is through the air-sea exchange of CO2 in the continental margins. The second, more indirect pathway is the supply of (organic) carbon and nutrients to the open ocean, which can lead to downstream productivity and respiration changes that influence the air-sea CO2 balance of the open ocean. Both of these processes are poorly constrained. In this study we address these questions using an eddy-resolving physical/biogeochemical/ecological model (ROMS) to the California Current System (CCS). The biogeochemical/ecological model is the Biogeochemical Elemental Cycling model of Moore et al. (2004) (BEC). It includes four phytoplankton functional groups (picoplankton, diatoms, coccolithophores, diazotrophs (Trichodesmium spp.) with multiple nutrient limitation (N, P, Si, Fe), an adaptive zooplankton class, dissolved organic matter (including suspending particulate detritus) and sinking particulate detritus. The ecosystem is linked with an ocean biogeochemistry module based on an expanded version of the OCMIP biotic model. Full carbonate system thermodynamics are included, allowing for computation of surface water pCO2 and air-sea CO2. The model results are evaluated with both in situ and satellite data. The model is used to estimate the carbon budgets in the area and the offshore transports into open oceans. The analysis of Nagai et al. (2008) reveals the dominant roles of eddies in the offshore carbon transport, about 60-90% of the offshore transports of macro-nutrients and organic carbon in the ~ 200-800 km range is caused by the westward propagating eddies. Keywords: Diagnosis, Attribution, Coastal Synthesis

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186: Variability of carbon sinks and fluxes in coastal ecosystems

186: Variability of carbon sinks and fluxes in coastal ecosystems Bror Fredrik Jonsson, Princeton University, bjonsson@princeton.edu (Presenting) Amala Mahadevan, Boston University, amala@bu.edu Joseph Salisbury, University of New Hampshire, joe.salisbury@unh.edu We examine the temporal variability of the carbon sink in two prototypical oceanic regions on the eastern and western North American continental margins. This is done by estimating the time-evolution of net community production (NCP) in the regions using satellite fields and ocean circulation modeling. We thereby calculate the export of phytoplankton carbon from the regions, and find strong inter-annual variability in both NCP and export. Using modeling, we estimate and examine the variability in chlorophyll to carbon ratios (Chl:C) at these sites. We find that even though the spread in Chl:C changes seasonally, the mean is not significantly altered in time. Seasonal variability seems to be small as compared to event-based variability, not only on the western margin off of California, but even on the eastern continental margin in the Gulf of Maine. Keywords: Diagnosis, Regional/Continental Synthesis 187: Use of the MICA System for Coastal CO2 Research

187: Use of the MICA System for Coastal CO2 Research Xuewu Liu, University of South Florida, College of Marine Science, 140 7th Ave. South, St. Petersburg, FL 33701, liu@marine.usf.ed (Presenting) Robert H Byrne, University of South Florida, College of Marine Science, 140 7th Ave. South, St. Petersburg, FL 33701, byrne@marine.usf.edu Lisa L Robbins, U.S. Geological Survey, St. Petersburg, FL 33701, USA, lrobbins@usgs.gov Paul Knorr, pknorr@usgs.gov Geoffrey Lebon, Ocean Climate Research Division, NOAA/PMEL, 7600 Sand Point Way NE, Seattle WA 98115, geoffrey.t.lebon@noaa.gov Simone Alin, Ocean Climate Research Division, NOAA/PMEL, 7600 Sand Point Way NE, Seattle WA 98115, simone.r.alin@noaa.gov Richard A Feely, Ocean Climate Research Division, NOAA/PMEL, 7600 Sand Point Way NE, Seattle WA 98115, richard.a.feely@noaa.gov MICA is an autonomous multi-parameter flow-through CO2 system developed for simultaneous measurements of surface seawater pH, carbon dioxide partial pressure (fCO2), total dissolved inorganic carbon (DIC) and total alkalinity (TA). All of the measurements are based on spectrophotometric determinations of solution pH at multiple wavelengths using sulfonephthalein indicators. The pH and TA optical cells are machined from a PEEK polymer rod, and have a 15 cm optical pathlength. The fCO2 and DIC optical cells consist of Teflon AF 2400 (DuPont) capillary tubing sealed within a bore hole also machined from PEEK. The Teflon AF tubing, filled with a standard indicator solution that has a fixed total alkalinity, forms a liquid core waveguide (LCW). The LCW functions as both a long pathlength (15 cm) optical cell and a membrane that equilibrates the internal standard solution with either external air (providing air pCO2), seawater (providing seawater fCO2), or acidified seawater (providing DIC measurements). Both pCO2 and DIC are then determined by measuring the pH of the internal solution. The MICA system has been deployed previously to obtain high quality CO2 system datasets across ocean basins. The system makes repetitive observations with measurement frequencies on the order of seven samples per hour. Measurement precisions in the field have been evaluated as ± 0.0008 units for pH, ± 0.9 μatm for pCO2, and ± 2.4 μmol kg-1 for DIC. These precisions are close to those obtained with conventional methods in the laboratory. In this report we present procedures for obtaining coastal CO2 measurements using MICA. Since the CO2 chemistry of the coastal ocean is exceedingly dynamic relative to the open ocean, much faster sampling rates are required. New procedures designed to address this challenge provide sample acquisition rates of approximately 30/hr. Keywords: Software Tools, Instruments, Data Management, Programmatic Topics 188: Satellite Assessment of CO2 Distribution, Variability and Flux and Understanding of Control Mechanisms in a River Dominated Ocean Margin

188: Satellite Assessment of CO2 Distribution, Variability and Flux and Understanding of Control Mechanisms in a River Dominated Ocean Margin Steven E Lohrenz, The University of Southern Mississippi, steven.lohrenz@usm.edu (Presenting) Wei-Jun Cai, University of Georgia - Athens, wcai@uga.edu More comprehensive information about carbon fluxes in margins is critical for quantitative assessments of their contribution to overall global carbon budgets. Margins that receive input from large rivers represent the extremes of continental shelf systems in carbon cycling and fluxes, and therefore should be a high priority in efforts to quantify regional carbon budgets. Recent findings in the vicinity of the Mississippi River plume demonstrate the highly variable nature of carbon fluxes in this system, and the need for both greater spatial and temporal coverage as well as an assessment of the underlying community metabolism driving patterns in surface CO2. The primary hypothesis of this research is that large river margin water columns exhibit extreme seasonal and spatial variability in air-sea CO2 fluxes, characterized by localized uptake driven largely by high rates of autotrophic production and loss of CO2 driven by high terrestrial inputs and heterotrophic respiration. Because of such extreme variability, constructing and characterizing spatially and temporally integrated air-sea fluxes (or in-turn predicting such fluxes) cannot be done by extrapolation or interpolation solely from discrete field measurements. A satellite-based regional approach must be an integral component of such an effort. Here, we describe a project funded by NASA and NSF that utilizes a multi-disciplinary but focused research approach involving four major activities including: 1) continuous, underway, shipboard assessments of carbon system properties and air-sea fluxes of CO2 and relationships to other variables, 2) satellite-derived assessments of regional scale pCO2 and air-sea carbon fluxes to quantify and assess spatial and temporal variations, and 3) targeted process measurements of planktonic net community metabolism and carbon fixation rates, and phytoplankton pigment composition and size structure, and 4) box-model exercises simulating plume mixing (estuarine mixing model, acid-base chemistry, and an inverse model to describe biological processes mediating carbon cycling and air-sea flux of CO2). This proposed study will provide quantitative information and robust observations for determination of emissions and uptake of CO2, and factors regulating these processes for the North American ocean margin. Keywords: Diagnosis, Attribution, Prediction, Site-level Synthesis, Regional/Continental Synthesis, Coastal Synthesis

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189: Remineralization in the Mid-Atlantic Bight and the Gulf of Maine inferred from climatologies of dissolved oxygen and primary production

189: Remineralization in the Mid-Atlantic Bight and the Gulf of Maine inferred from climatologies of dissolved oxygen and primary production Raymond Najjar, The Pennsylvania State University, najjar@meteo.psu.edu (Presenting) Jay O'Reilly, National Marine Fisheries Service, oreilly@narwhal.gso.uri.edu The decomposition of organic matter (remineralization) is a central process in marine biogeochemical cycles but is extremely difficult to measure directly. Here we combine climatologies of dissolved oxygen and satellite-based primary production with a simple 1-D mass balance model to estimate the mean annual cycle of remineralization in the well-sampled waters of the Mid-Atlantic Bight (MAB) and the Gulf of Maine (GOM). The dissolved oxygen climatology is based on historical measurements archived at the National Oceanographic Data Center. Primary production is based on a version of the Vertically Generalized Productivity Model, which has been shown to agree very well with historical in situ measurements. Remineralization is estimated from the time rate of change of dissolved oxygen, accounting for mixing, air-sea exchange, and primary production. Results from the central GOM suggest the following: (1) Respiration lags primary production; (2) the mixed layer is autotrophic March-November and heterotrophic December-February; (3) Mixed-layer net community production is about 30% of mixed-layer primary production on an annual basis. Results for other regions will be presented. Keywords: Diagnosis, Attribution, Site-level Synthesis, Coastal Synthesis 190: Satellite Remote Sensing of Pigments, Absorption, and Primary Production in the Northeast U.S. Coast

190: Satellite Remote Sensing of Pigments, Absorption, and Primary Production in the Northeast U.S. Coast Xiaoju Pan, NASA/GSFC, xpan@neptune-web.gsfc.nasa.gov (Presenting) Antonio Mannino, NASA/GSFC, antonio.mannino@nasa.gov Mary E Russ, NASA/GSFC, mary.e.russ@nasa.gov Stanford B Hooker, NASA/GSFC, stanford.b.hooker@nasa.gov At present, satellite remote sensing of coastal water quality and constituent concentration is subject to large errors as compared to the capability of satellite sensors in oceanic waters. In this study, field measurements collected on a series of cruises within the northeast U.S. coast were applied to improve retrievals of pigments and constituent absorption from SeaWiFS and MODIS-Aqua. Colored dissolved organic matter (CDOM) is the major contributor to the light absorption in this region, and causes significant overestimation of chlorophyll a concentration ([Chl_a]) from operational algorithms (e.g. OC4V4 and OC3M). Chl_a is the major phytoplankton pigment in the ocean, but it is not always linearly related to other photosynthesis pigments (e.g. Chl_b, Chl_c, Fucoxanthin, and Peridinin). The estimation of primary production based on single [Chl_a] may contain significant error. A new approach based on the model of Ocean Production from Absorption of Light (OPAL) and multiple pigment concentration and phytoplankton absorption was evaluated to estimate primary production in this region. Keywords: Attribution, Coastal Synthesis 191: Direct measurement of CO2 fluxes from Lake Superior

191: Direct measurement of CO2 fluxes from Lake Superior Noel R. Urban, Michigan Technological University, nurban@mtu.edu (Presenting) Judith A. Perlinger, Michigan Technological University, jperl@mtu.edu Jennifer W. Mwangi, Michigan Technological University, jwmwangi@mtu.edu Lucovic Bariteau, Cooperative Institute for Research in Environmental Sciences, University of Colorado, ludovic.bariteau@noaa.gov Chris W. Fairall, Physical Science Division, NOAA Earth System Research Laboratory, chris.fairall@noaa.gov Lake Superior is seasonally (spring, fall, winter) supersaturated with respect to atmospheric CO2. Empirical gas exchange models suggest that the CO2 efflux is 0.1-0.4 gC m-2 d-1. While these fluxes are small compared to daily or monthly averages over nearby terrestrial systems (-8 to +4 gC m-2d-2), annual fluxes estimated for the lake (~140 g C m-2 yr-1) are comparable in magnitude but opposite in direction to fluxes over nearby forests (-120 to -300 gC m-2 yr-1). Given the large surface area of Lake Superior, annual emissions of CO2 (~11 Tg C/yr) may be regionally significant. To better assess the magnitude of the flux, direct measurements (eddy covariance) of the CO2 flux above the lake were made on six occasions between August 2007 and October 2008. Measurements were made 1-20 km from shore in the central region of the lake. Eddy covariance (EC) instrumentation was mounted on a 10-m pneumatic mast on board the R/V Agassiz. A Crossbow AHRS300CA was mounted level with the sonic anemometer to enable the measured wind vectors to be corrected for ship motion. Adequacy of the motion correction was verified by power spectral analysis of vertical wind speeds, comparison of EC fluxes with bulk aerodynamic calculations, and comparison of latent and sensible heat fluxes with other estimates of these fluxes. Measurements were conducted for an hour at each station; 10-minute average fluxes were computed, and these were then averaged to yield hourly means. The EC CO2 fluxes were in the range of 0.15 to 0.63 g C m-2 d-1, similar to the range of estimates cited above. The mean (+ 95% CI) of all measured fluxes (0.28 + 0.15 g C m-2d-1 or 100 g C m-2yr-1) supports the conclusion that Lake Superior is a regionally significant source of CO2 to the atmosphere. Keywords: Diagnosis, Site-level Synthesis, Regional/Continental Synthesis, Coastal Synthesis 192: Carbon Measurements in the Gulf of Maine

192: Carbon Measurements in the Gulf of Maine Douglas Vandemark, UNH/EOS, doug.vandemark@unh.edu (Presenting) Joseph Salisbury, UNH/EOS, joseph.salisbury@unh.edu Chris Hunt, UNH/EOS, chris.hunt@umh.edu Shawn Shellito, UNH/EOS, shawn.shellito@unh.edu Robert Talbot, UNH/EOS, robert.talbot@unh.edu

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Ruth Varner, UNH/EOS, ruth.varner@unh.edu Wade McGillis, LDEO, wrm2102@columbia.edu Christopher Sabine, NOAA/PMEL, chris.sabine@noaa.gov Stacy Maenner, NOAA/PMEL, stacy.maenner@noaa.gov This study focuses on coastal ocean observations collected by the University of New Hampshire to evaluate and quantify air-sea CO2 flux dynamics in a highly productive marginal sea - the Gulf of Maine located on the NW Atlantic shelf. While this region has been intensively studied for decades, this work will provide the first annual estimates of net CO2 flux at the air-sea interface. It appears that the seasonally stratified GOM is a source of CO2 to the atmosphere despite a significant net production of organic carbon. This occurs because the large spring bloom CO2 drawdown due to phytoplankton growth is more than offset by the fall-to-winter recharge of the surface layer dissolved inorganic carbon and enhanced wind-driven gas exchange. The study utilizes a unique East Coast coastal ocean carbon data set that spans from 2004-present and includes monthly shipboard spatial coverage of inner, mid, and outer shelf stations as well as a moored CO2 measurement platform with hourly time resolution. The variability of atmospheric CO2 levels within the marine boundary layer is also a point of concern in mass flux estimation goals within the NACP program. We will present observations showing that while significant atmospheric variability is evident at diurnal to synoptic meteorological time scales, the net impact on air-sea exchange is likely to be small in our region and consistent with results seen off the coasts of Europe. Keywords: Diagnosis, Attribution, Coastal Synthesis 193: The Effects of Land Use on Riverine CO2 Isotopic Signatures in the US Gulf Coast

193: The Effects of Land Use on Riverine CO2 Isotopic Signatures in the US Gulf Coast Fanwei Zeng, Rice University, fwzeng@rice.edu (Presenting) Carrie A. Masiello, Rice University, masiello@rice.edu Rivers are generally supersaturated with CO2 relative to the atmosphere. However, high spatial variation exists in sources of excess riverine CO2, primarily due to dominance of different controls (e.g. geologic setting, climate, land use, and human activities) on carbon sources. In our study conducted in Buffalo Bayou and Spring Creek in Texas from June 2007 to October 2008, we directly measured pCO2 (partial pressure of CO2) of river waters to estimate CO2 emission rates of subtropical rivers, and we analyzed carbon isotopic signatures (δ13C and Δ14C) of riverine dissolved inorganic carbon (DIC) and particulate organic carbon (POC) to determine primary sources of riverine CO2. CO2 was supersaturated on all dates and at all sites sampled, with pCO2 values higher in summer and fall and lower in winter and spring. Annual average pCO2 values are 3033 µ atm and 4118 µ atm for Buffalo Bayou and Spring Creek, respectively, comparable to those in the Amazonian rivers. A pronounced spatial pattern in δ13C and Δ14C of DIC was observed: compared with DIC in river waters farther inland, DIC in river waters closer to the coast is more depleted in 14C and enriched in 13C. This is coincident with the distribution of shell roads built throughout the Gulf coast between late 19th and mid 20th century. We hypothesize that dissolution of shells used in road construction is the source of 14C-depleted and 13C-enriched DIC and thus is likely an important source of CO2 in river waters in the Gulf coast. Keywords: Diagnosis, Attribution, Site-level Synthesis, Coastal Synthesis

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Index of All Authors by Last Name Abstracts highlighted in bold indicate that the associated author is the first author on that abstract.

Author Abstract(s) Agarwal, Deb 4.A Aiken, George 179

Alanís, Armando 161

Albrecht, Stephan L 110

Aleks, Gretchen Keppel 137

Alin, Simone R. 187, 3.C, 9.D, 177, 8.B

Alix, Claire 32

Amiro, Brian 4.A

Anaya, Carlos 162

Andersen, Hans E 19

Anderson, Ryan 4.A, 9

Anderson, Tyler 83

Andrade, David 169

Andres, Robert J 3.D, 1

Andrews, Arlyn E. 139, 14, 149, 158, 173, 2.A, 5.D

Andrysco, Nathan 11

Arabia, Laure 187

Arain, Altaf M. 4.A, 72

Arora, Vivek K 9.A

Art, Henry W. 141

Atilla, Nazan 178

Azuma, David 34

Bachelet, Dominique 88

Baker, Ian T 167, 168, 172, 4.A, 2

Baker, J. M. 5.A

Baker, John 101

Baker, John M 142

Balbontin, C. 112

Balch, William M 179

Baldocchi, Dennis 4.A

Balser, Teresa 105

Bariteau, Lucovic 191

Barnard, Andrew 179

Barr, Alan 4.A

Barr, Alan G. 131

Barrett, Kirsten 150, 3.B

Baskaran, Latha M. 127, 76

Battle, Mark O 3 Bauer, Jim 8.A

Beck, Pieter 31, 32

Benes, Bedrich 11

Benner, Ron 8.A

Bennington, Valerie 178

Benscoter, Brian 3.B

Bernacchi, Carl J 126, 142, 30, 5.A

Bernier, Pierre Y. 131, 72

Berry, Joseph A 35, 172

Bianchi, Tom 8.A

Biles, Frances 181

Billesbach, David P 142

Billings, Sharon Alene 107

Birdsey, Richard A 101, 2.B, 4, 99, 10.A, 108

Black, Andy 4.A

Black, T. Andrew 131

Blackard, Jock A. 60

Blake, Donald R. 71

Blake, Nicola J. 71

Blough, Neil 187

94

Boden, Tom A 1, 4.A

Boer, George J 9.A

Boisvenue, Celine 10.C

Bolstad, Paul 4.A, 9

Bonan, Gordon B 80

Bontempi, Paula 1.B

Borr, Matthew 150, 3.B

Bouldin, Jim 33 Bourgeau-Chavez, Laura L. 150, 3.B

Boutton, Thomas W. 113, 48

Boyer, Elizabeth 8.A

Boyle, Eryn 187

Bradford, James A 142

Bradford, John B 108, 4

Brandt, Craig C 127

Braswell, Bobby H 62

Bray Beltran Villarreal, Bray 70

Breidt, F. Jay 5.C

Brigham, Brian 5 Browell, Edward V. 7, 6

Bruhwiler, Lori 9.B

Bruland, Gregory L. 115

Bunn, Andy 32

Burba, George 83 Burns, Sean 4.A

Burnside, Todd J. 3.B

Butler, James H 14

Butler, Martha 2.A

Butnor, John 15

Byrne, Robert H 187

Cadenasso, Mary 15

Cahill, Bronwyn 183

Cai, Wei-Jun 188, 3.C, 8.A

Callaham, Mac A. 40

Campbell, J Elliott 172

Campbell, John 34 Campbell, John Elliott 35 Campbell, Steve L. 4.A, 76

Campo, Julio 114

Canham, Charles D. 69

Carpenter, John 3

Carvalhais, Nuno 97

Causarano, Hector 111

Chai, Fei 8.A

Chan, Douglas 2.B

Chapman, Bruce 28

Chapman, Samantha 109

Chappelka, Art 70

Chavas, Daniel R. 166

Chen, Bin 72

Chen, Guangsheng 175, 4.A, 95

Chen, Guangsheng 70

Chen, Jing M. 21, 4.A, 72, 2.B

Chen, Jiquan 10

Cheng, Yen-Ben B. 44

Cherrey, Kelly 9

Choi, Kichul 7

Choi, Yonghoon 26, 6, 71, 7

Chopping, Mark James 8

Christian, James R 9.A

Ciais, Philippe 4.A

Ciais, Philippe 2.C

Clark, Kenneth 108

Coble, Paula 8.A, 180

Cohen, Warren B. 102, 144, 159, 24, 34, 51, 56, 60, 7.C, 138

Collatz, Jim 104, 138, 139, 60, 97

Collins, Harold P 110

95

Comerford, Nicholas B. 115

Committee, Operational Science 36

Conway, Thomas J 14

Cook, Bob 4.A

Cook, Brian 106

Cook, Bruce 9

Cook, David R 120, 121, 142, 4.A

Cook, Robert B. 7.A, 76

Cooley, Dan 5.C

Coops, Nicholas C 72, 79

Corbin, K. D. 157

Corbin, Kathy 11, 167, 168, 2.A, 5.D

Cordova, Vicente D. 23

Corp, Lawrence A. 44

Coulter, Richard L 142

Coursolle, Carole 36 Covey, Curtis C 80

Crosson, Eric 168

Cruz, C. O. 112

Culvenor, Darius 86

Curry, Charles L 9.A

Curtis, Carroll N. 76

Curtis, Peter 4.A

D'Amore, Dave 181

Daly, Chris 88

Dan, Loeffler 116

Daughtry, Craig 111

Davidson, Eric A 129

Davis, Kenneth J. 108, 133, 147, 168, 2.A, 4.A, 4.B, 5.C, 5.D, 9.C, 1.C, 9

Davis, Zane A 3

Day, Doug 67

de Groot, William 3.B, 50

de Jong, Bernardus H.J. 112, 162, 161

de la Rue du Can, Stephanie 11

De La Torre Ugarte, Daniel G 127

Delgrosso, Steve 4.A

Deng, Feng 2.B

Denman, Kenneth L 9.A

Denning, Scott 11, 139, 157, 167, 168, 172, 2, 5.C, 5.D, 2.A

Desai, Ankur R 133, 178, 9, 163

Detwiler, Andrew G 142

Deutsch, Curtis 185

Dickson, Andrew 8.B

Dietze, Michael 4.A, 89

Dietze, Michael C 133

Dilling, Lisa 10.B

Dimitrov, Dimitre D. 4.A, 37

Diskin, Glenn S. 71

Dobbs, Michael E. 6

Dobler, Jeremy 6

Domec, JC 10

Doney, Scott C. 185

Doraiswamy, Paul 111

Downing, Mark E 127

Dragoni, Danilo 4.A, 130

Drapek, Raymond J 88

Drolet, Guillaume 140

Duane, Maureen 159, 7.C

Ducey, Mark J. 146

Dugas, William A 142

Dungan, Jennifer L. 141

Dunn, Allison L. 131

Dymond, Caren 10.C

Ederer, Gregory A 74

96

Edwards, Mary 92

Edwards, Rick 181 Ehleringer, James 54

El Maayar, Mustapha 2.B

Eluszkiewicz, Janusz 173, 67

Emanuel, Ryan 63

Entcheva Campbell, Petya K. 44

Epstein, Howard E. 4.A, 63

Erickson, David J 139

Erickson, Tyler A 77

Etchevers, Jorge Dionicio 114, 112

Evans, Wiley 8.B, 38

Failey, Elisabeth 10.B

Fairall, Chris W. 191

Falk, Matthias 4.A

Faloona, Ian 67

Feely, Richard Alan 184, 187, 3.C, 8.B, 9.D

Fennel, Katja 183, 8.A, 182

Fichot, Cedric G. 59

Filley, Timothy R. 113 Finzi, Adrien C. 90 Fischer, Marc L. 11, 173, 4.A, 67

Fiske, Greg 118

Flanagan, Lawrence B 142, 4.A

Flannigan, Mike 3.B

Flato, Gregory M 9.A

Follet, Ronald 101

Fox, Andrew M 133

Frank, Albert B 142

Fransen, Stephen J 110

French, Nancy HF 123, 3.B, 50, 77

Frenzel, Hartmut 185

Friedrichs, Marjorie 8.A, 183

Froberg, Mats J. 41

Frolking, Steve 156

Fung, Inez Y 80, 91

Ganem, David 57

Gao, Feng 74

Gao, Feng 56

Garten, Charles Jr T 122

Gausephol, Sheri Conner- 172

Gavazzi, Michael 10 Giasson, Marc-André 36

Gilmanov, Tagir G 170, 142

Gitelson, Anatoly A 39

Gleason, Robert 55

Goeckede, Mathias 7.C, 143

Goetz, Scott J 32, 31

Goldstein, Allen 4.A

Gomez, Jesus David 114 Gomez-Casanovas, Nuria 121

Goncalves, Fabio 25

Gonzalez, Patrick 88

Gonzalez-Meler, Miquel A. 120, 121, 47

Goodale, Christine L. 103, 16, 69, 90

Goulden, Mike 17, 4.A

Gourdji, Sharon M 148, 149

Govind, Ajit 72

Goward, Samuel N. 102, 13, 138, 24, 51, 56, 60, 144

Graham, Scott 120

Grant, Robert F. 3.A, 37, 4.A, 72, 131

Greeley, Dana 9.D

Gregg, Jay 106

Gregg, Jay S 1

Gretchen, Moisen 116

Griffis, Timothy J 142, 5.A

Griffith, Peter 1.A, 78

Groffman, Peter M 15

97

Grosse, Guido 92 Gruber, Nicolas 185

Grunwald, Sabine 115

Gu, Lianhong 132, 154, 22, 4.A, 145

Guerrero, Gabriela 162

Guilderson, Tom 40, 41

Guindon, Luc 72

Gurney, Kevin Robert 3.B, 11, 3.D

Haferkamp, Marshall R 142

Haidvogel, Dale 183

Hales, Burke 177, 184, 3.C, 38, 8.B, 9.D

Hall, Forrest 56

Hall, Forrest G 79

Hall, Ron 3.B

Ham, Jay M 142

Hanan, Niall 4.A

Hansen, Matt 167

Hanson, Paul J. 46, 40, 41

Hao, Wei Min 42 Harden, Jennifer H. 101, 3.B, 49, 50

Harmon, Mark E 66

Harris, Willie G. 115

Harrison, F. Wallace 6

Hart, Ryan 3

Hashimoto, Hirofumi 141

Hastings, Steven 83

Hatfield, Jerry L. 111, 164, 170, 5.A, 165

Hawthorne, Iain 4.A

Hayes, Daniel J. 3.B, 12

Healey, Sean 51

Healey, Sean 102

Healey, Sean P. 24, 60, 116

Heath, Linda S. 10.A, 108, 146

Heilman, James L 142

Heimann, Martin 2.C

Helliker, Brent R 163

Hellwinckel, Chad M 127

Hember, Robbie 72

Hernandez-Ayon, Martin 3.C, 8.B, 184

Hernandez-Ramirez, Guillermo 165, 170, 164

Heuer, Mark W 142

Hicke, Jeffrey A. 43

Hickman, George 30

Hilker, Thomas 79

Hilton, Timothy W 2.A, 4.A, 147

Hinds, Adrienne 102, 60

Hirsch, Adam I. 149, 173

Hoffman, Forrest M 4.A, 80

Hofmann, Eileen 183

Hogg, E. H. 75

Holland, Amanda K. 15

Hollinger, David Y 108, 140, 156, 4.A, 62

Hollinger, Steven E 142

Hom, John 108

Hood, Eran 181

Hooker, Stan B. 18

Hooker, Stanford B 190

Hoover, Coeli M 10.A, 108, 117

Hopkinson, Chuck 8.A

Hoppus, Mike 118

Hoy, Elizabeth 150, 3.B, 50

Huang, Chengquan 102, 138, 24, 51, 56, 60, 13

Hudiburg, Tara 159, 4.A, 7.C, 93

Huemmrich, Karl Fred 44

98

Humphreys, Elyn 37

Hunt, Chris 192

Hunt, Christopher 8.C

Huntington, Thomas 179

Huntzinger, Deborah N. 149, 7.A, 148

Hyde, Kimberly 183

Ianson, Debby 184, 3.C, 8.B

Iglesias, Leonel 161

Ikawa, Hiroki 83

Ilyushchenko, Simon 11

Ishizawa, Misa 4.A

Ishizawa, Misa 2.B

Iversen, Colleen M 98

Izaurralde, Roberto C. 111, 4.A, 166

Jacobson, Andy 2.A, 7.A, 14, 7.B

Janssens, Ivan 2.C

Jastrow, Julie D. 101, 113, 122, 40, 41, 45, 47, 46, 48

Jauss, Verena 94 Jenkerson, Calli B. 81

Jenkins, Jennifer C 15 Jenkins, Julian P. 103, 62, 16

Jin, Xin 185

Jin, Yufnag 31, 17

Jock, Blackard 116

Johnson, Arthur H. 141

Johnson, Kristofer 49 Johnson, Mark 101

Johnstone, Jill F. 150, 3.B

Jones, Dylan B.A. 21

Jones, Greg 116

Jonsson, Bror Fredrik 8.C, 186

Juday, Glenn 32

Jullien, Alexie 187

Jupp, David 86

Juranek, Laurie 8.B, 9.D

Kane, Evan S. 3.B, 50

Karion, Anna 67 Kasischke, Eric S. 150, 3.B, 50

Kawa, S R 139 Kawa, S Randolph 172

Kazuhito, Ichii 141

Keilland, Knut 150, 3.B

Keller, Klaus 9.C

Kellndorfer, Josef 118 Kelly, Robin 4.A

Kennedy, Robert E. 102, 138, 24, 34, 60, 7.C, 51

Keppel-Aleks, Gretchen 176

Kicklighter, David W 12

Kicklighter, David W. 3.B

Kim, Youngwook 57

Kimball, John S 57, 75

Kimura, Nobuaki 178

King, Anthony Wayne 132, 22, 151

King, Jennifer Y 52

King, John 10

King, Tony 1.C, 145, 4.A

Kirsch, Katie 118

Klooster, Steven 124

Knorr, Paul 187

Kolka, Randy K 101, 4, 9, 52

Kooi, Susan A. 6, 7

Krakauer, Nir 91

Kramer, Marc Gerald 53 Krull, Evelyn 94

Kucharik, Christopher 4.A

Kujawinski, Elizabeth 187

Kurz, Werner 161, 3.B, 72

Kurz, Werner Alexander 10.C

99

Kustas, William P. 44

Lachkar, Zouhair 185

Lafleur, Peter 4.A

Lai, Chun-Ta 5, 54

Langdon, Chris 3.C

Langley, Adam 109

LaPoint, Elizabeth 118, 82

Larry, DeBlander 116

Lauvaux, Thomas 2.A

Law, Beverly Elizabeth 138, 143, 159, 4.A, 8.B, 93, 7.C

Lebon, Geoffrey 187

Lee, Cindy 183

Lee, Kitack 9.D

Lehman, Scott J 58

Lehmann, Johannes 101, 94

Lenihan, James M 88

Li, Ainong 13

Li, Shuyong 22

Li, Zhengpeng 119, 128, 4.A, 55

Lilly, Paul J. 15

Lindroth, Anders 140

Lipson, David 5

Liu, Leo 4.A

Liu, Mingliang 175, 4.A, 70, 95

Liu, Shuguang Liu 128, 133, 160, 55, 68, 119

Liu, Xuewu 187

Lloyd, Andrea 32

Loboda, Tatiana 150, 3.B

Loher, Damian 185

Lohrenz, Steven E 188, 8.A

Lokupitiya, E. 5.A

Lokupitiya, Erandi 4.A, 167

Long, Daniel S 110

Losey, London 1

Lu, Chaoqun 175, 70

Lu, Lixin 64

Luo, Yiqi Q 133, 136, 4.A, 9.C

Luyssaert, Sebastiaan 2.C

Lv, Chaoqun 95

MacDonald, Clinton 173

Mack, Michelle 31

Mackay, D Scott 163

Maenner, Stacy 192, 3.C

Mahadevan, Amala 186, 8.C

Maloy, Carol 8.B

Manies, Kristen 3.B, 49, 50

Mannino, Antonio 183, 190, 18

Manowitz, David 166

Margolis, Hank A. 131, 140, 19, 36, 4.A, 3.A

Marland, Gregg 1

Marrin, D.L. 96 Martin, Mary E 156

Martinez, René 162

Martins, Douglas K 5.D, 153

Masarie, Kenneth A 14

Masek, Jeff B. 24

Masek, Jeffery G. 144

Masek, Jeffrey G 13, 51, 56

Masek, Jeffrey G 104, 39

Masek, Jeffrey G. 102, 138, 60

Masera, Omar 162

Masiello, Carrie A. 193

Matamala, Roser 121, 142, 4.A, 40, 120, 122

Matrai, Patricia 20

Mays, David A. 174

McCaughey, Harry 4.A

100

McClain, Charles 183

McCreight, James 65

McCullough, Kevin 99

McCullough, Kevin 2.B

McDermitt, Dayle 83

McDonald, Kyle C. 27, 28, 75, 57

McFarlane, Karis 40

McGillis, Wade 192

McGlinchy, Maureen 88

McGlynn, Brian L. 63

McGuire, David 12, 150, 3.B, 49

Mckane, Robert 101

McKee, Brent 8.A

McKenzie, Don 123 McKenzie, Don 3.B

McKenzie, Donald 77

McKinley, Galen A. 178

McMurtrie, Ross E 98

McNulty, Steve 10

McWilliams, James C. 185

Meddens, Arjan J.H. 43

Medlyn, Belinda E 98

Melillo, Jerry M 12

Melillo, Jerry M. 3.B

Mendoza, Daniel 11

Merryfield, William J 9.A

Metsaranta, Juha Mikael 10.C

Meyer, David J. 81

Meyers, Tilden P 142, 4.A, 5.A

Michaelis, Andrew 141

Michalak, Anna 1.D, 2.A

Michalak, Anna 143

Michalak, Anna M 135, 148, 149

Middleton, Elizabeth M. 140, 44

Mielnick, Patricia C 142

Miles, Natasha 168, 5.D

Miles, Natasha 2.A

Miller, Ben 67

Miller, Bill 8.A

Miller, Chris 11

Miller, Jesse N. 22, 154

Miller, John B 14, 58

Miller, Lloyd 67

Miller, Michael R 122

Miller, Rick 34

Miller, William L. 59 Mo, Gang 2.B

Moghaddam, Mahta 27, 28

Moisen, Gretchen G. 102, 138, 144, 24, 51, 56, 60

Monson, Russell 4.A

Monterroso, Alejandro Ismael 114

Montzka, Stephen A 172, 67

Moorcroft, Paul R 163, 89

Moore III, Berrien 6

Moran, Kelly K. 113, 46, 48, 45

Morgan, Jack A 142

Morgan, Todd 116

Morisette, Jeffery T 74

Morrell, Amy 78

Mueller, Kim L 135, 148, 149

Munger, Bill 4.A

Musielewicz, Sylvia 3.C

Muth, Daniel 63

Mwangi, Jennifer W. 191

Myers, Brenton D. 115

Nagai, Takeyoshi 185

Najjar, Raymond 182, 183, 8.A, 189

101

Nassar, Ray 21 Navar, Jose de Jesus 155, 61

Neff, D. 84 Nehrkorn, Thomas 173

Nehrkorn, Thomas 67

Neigh, Chrisotpher S.R. 97

Neilson, Eric 10.C

Neilson, Ronald P 100, 88

Nelson, Richard G 127

Nelson, Ross F 19 Nemani, Ramakrishna 141

Newnham, Glenn 86

Newton, Jan 8.B

Ni-Meister, Wenge 86

Nichols, Jeff 4.A

Nightingale, Joanne M 74

Noormets, Asko 10

Norby, Richard J 98 Nordgren, Bryce L. 42

Nowak, Robert 99

Nyakatawa, Ermson Z. 174 O'Brien, Sarah L. 113, 46, 48, 47

O'Reilly, Jay 189

O'Reilly, John 183

Oberbauer, Steven 83

Oechel, Walter C. 4.A, 75, 83

Ogle, Stephen M. 171, 5.B, 5.C

Ojima, Dennis 11

Olguin, Marcela 161, 162

Ollinger, Scott V. 103, 16, 4, 62, 156

Olsen, Lisa M. 76

Oren, Ram 4.A, 99

Orrico, Christina 179

Ottmar, Roger D. 123, 3.B, 50

Owensby, Clenton E 142

Palafox, Rigoberto Rivas 24

Pan, Jerry Y. 76

Pan, Shufen 70

Pan, Xiaoju 190 Pan, Yude 108, 2.B, 99

Pan, Zaitao 169 Parazoo, N. C. 157

Parkin, Timothy B 164, 165, 170

Parton Jr., William J. 40

Parton, William J. 101, 4.A, 41

Pattey, Elizabeth 4.A

Paustian, Keith 167

Paz, F. 112

Pedelty, Jeffery A 74

Peng, Changhui 4.A, 72

Peng, Tsung-Hung 3.C

Perlack, Robert D 127

Perlinger, Judith A. 191

Perry, Eileen M 110

Perry, Rebecca 3

Peters, Wouter 14

Petkov, Alex 42

Peylin, Philippe 4.A

Pfeifer, Eric 43

Piao, ShiLong 4.A

Pierce, Francis J 110 Pilskaln, Cindy 8.A

Pinjuv, Guy 88

Pittman, Kyle 167

Plattner, Gian-Kasper 185

Plourde, Lucie C 156

Plug, Lawrence 92

Podest, Erika 27, 28, 57

102

Pollard, David 183

Porras, Rachel C. 46

Post, Wilfred M. 101, 132, 145, 151, 154, 166, 4.A, 4.B, 76, 9.C, 22, 7.A

Potter, Christopher 7.C, 124

Poulter, Ben 4.A

Poulton, Nicole 20

Powell, Scott L. 102, 24, 51, 60

Previdi, Michael 182

Price, David 4.A, 72

Prihodko, Lara 2

Prueger, John H. 142, 164, 165, 44, 170

Raczka, Brett 4.A

Rahman, A. Faiz 23 Rai, S C 125

Randerson, Jim 17, 31, 80

Randolph, James C 130

Rauschenberg, Carlton 20

Raymond, Peter 8.A

Rayner, Peter 2.A

Reader, Heather 59

Reich, Peter B 156

Ren, Wei 175, 70, 95

Ricciuto, Daniel M 151, 4.A, 132, 133

Richardson, Andrew D 133, 156, 4.A, 89, 62

Richardson, Scott 168, 2.A, 5.D

Riciutto, Dan 145

Riemann, Rachel 85

Riley, William J. 4.A

Rishmawi, Khaldoun 102, 60

Ritchie, Michael 120

Ritts, David 159, 7.C

Riveros-Iregui, Diego A. 63

Robbins, Lisa L 180, 187, 8.A

Roesler, Collin 179

Rogers, Brendan M 88, 100

Román, Miguel O. 134

Romanovsky, Vladimir 92

Running, Steven W 80, 9

Rupp, T. Scott 150

Russ, Andrew L. 44

Russ, Mary E 190

Ryan, Michael 4.A

Ryan, Michael 108

Ryan, Michael G 4

Sabine, Christopher L. 184, 192, 8.B, 9.D, 1.D, 3.C

Sachse, Glen W. 71

Sahoo, Alok 4.A

Saliendra, Nick 4.A, 9

Salisbury, Joseph 186, 192, 3.C, 8.A, 8.C

Sanderman, Jonathan 53

Saripalli, Suman 67

Sauer, Tom J 164, 165, 170

Schaaf, Crystal B. 4.A, 8, 86, 134

Schaefer, Kevin M 133, 2, 4.A, 65, 64, 9.B

Scheckman, Jacob 3

Schedlbauer, Jessica 83

Schleeweis, Karen 102, 24, 51, 60

Schmid, Alex 3.B

Schmid, Hans Peter 130

Schneider, Tapio 137

Schroeder, Todd A. 24 Schuh, Andrew E. 2.A, 4.A, 157

Schulze, Ernst-Detlef 2.C Scinocca, John F 9.A

103

Segal, Moti 169

Setiyono, T. 5.A

Shaefer, Kevin 167

Sharma, Purnima 125

Shellito, Shawn 192

Shenoy, Aditi 150, 3.B

Shepson, Paul B 153, 5.D

Sheridan, Ryan 43

Sherwood, Tom 67

Shi, Hua 13

Sieracki, Michael 20

Sierra, Carlos A 66 Signorini, Sergio 183

Simpson, Brian Nelson 10.C

Sims, Phillip L 142

Slater, Lee 92

Smith, David 174

Smith, Marie L. 4

Smith, Pete 2.C

Sofen, Eric 3

Sohl, Terry 128

Song, Xia 70

Soussana, Jean-Francois 2.C

Spencer, Shannon L 171 Sprintsin, Michael 2.B, 4.A

Starr, Gregory 83

Stine, Zan 91

Stinson, Graham 10.C, 72

Stirm, Brian H 153

Stoy, Paul 4.A

Strahler, Alan H. 134, 86

Strutton, Peter 177, 3.C, 38, 8.B

Sturtevant, Cove 83

Sulman, Ben 9

Sun, Ge 70

Sun, Ge 10

Sun, Jianfeng 72

Suyker, A. E. 5.A

Suyker, Andrew E 39

Swann, Abby 91

Swanston, Christopher W. 41, 46, 101

Sweeney, Colm 14, 153, 5.D, 58, 67, 158

Takle, Eugene S. 169

Talbot, Robert 192

Tan, Bin 74

Tan, Zhengxi 119, 68

Tans, Pieter P 14, 158, 58

Tao, Bo 68

Team Participants, Regional/Continental Interim-Synthesis

7.A

Thomas, Nancy E. 13, 24, 51, 60, 102

Thomas, R. Quinn 69

Thomson, Allison M. 166

Thornton, Peter E. 101, 4.A, 76, 76, 80, 9.C, 90, 93, 1.A

Tian, Hanqin 4.A, 8.A, 95, 175, 70

Tieszen, Larry L 142

Toney, Chris 13

Tonitto, Christina 16, 4.A, 103

Toon, Geoffrey C 176

Torbert, Allen 174

Torn, Margaret S. 101, 142, 4.A, 40, 41, 46

Tortell, Phillippe 8.B

Tracey, Frescino 116

Treasure, Emrys 10

Treat, Claire 3.B

Treuhaft, Robert 25

104

Trofymow, Tony 72

Trumbore, Susan E. 101, 129, 40, 41

Tucker, Compton Jim 97

Tunnicliffe, Verena 8.B

Turetsky, Merritt R. 150, 3.B, 50

Turner, David P. 138, 143, 7.C, 159

Twine, Tracy E 126

Tyler, Stanley C. 71

Ulliasz, M. 157

Urban, Nathan M 9.C

Urban, Noel R. 178, 191

Urbanski, Shawn P. 116, 42

Vadrevu, Krishna Prasad 7, 26

van Ingen, Catharine 4.A

Vance, Eric 101

Vandemark, Douglas 3.C, 8.A, 8.C, 192

VanLoocke, Andy David 30, 126

Vargas, Rodrigo 4.A

Varner, Ruth 192

Vay, Stephanie A. 137, 26, 7, 71

Verbeeck, Hans 4.A

Verma, Shashi B 39, 4.A, 5.A

Vickers, Dean 143

Villarreal, Bray Beltran 95

Viña, Andrés 39

Viovy, Nicolas 4.A

Vlahos, Penny 8.A

Vogelmann, James 13

Waddington, Mike 3.B

Waldrop, Mark 101

Walker, Wayne 118

Walter, Katey 92

Wang, Shusen 131

Wang, Weile 4.A, 141

Wang, Zhuosen 134, 8

Wang, Ziyu 72 Wanninkhof, Rik 3.C

Warren, Jeffrey M 98

Watts, Dexter 174

Way, Tom 174

Wayson, Craig A 130

Weathers, Kathleen C. 69

Wei, Yaxing 76

Weishampel, Peter 4, 52, 9

Wells, John R 88

Welsch, Daniel 63

Weng, Ensheng 4.A, 9.C

Wennberg, Paul O 137, 176

West, Larry 101

West, Tristram O 166, 5.C, 127, 5.B

Westfall, James 118

Whitcomb, Jane 27, 28

Wielopolski, Lucian 87 Wiggert, Jerry 8.A

Wilcox, Lisa 78

Wilkin, John 182, 183

Williams, Christopher A 4.A, 104

Williams, Jimmy R. 166

Williams, Mathew 133

Wilson, Barry Tyler 85

Wilson, Bradly S 127

Wixon, Devin 105

Wofsy, Steven C. 139, 2.A, 4.B, 6.A

Wolf, Adam 172

Wolfe, Robert E 56, 74

Woo, Jung-Hun 7

Woodbury, Peter 94

Woodcock, Curtis 134, 86

105

Woogerd, Jayme 3

Wu, Chin 178

Wulder, Michael A. 24, 60

Wulder, Mike 19

Wunch, Debra 176 Wylie, Bruce K 142

Xiao, Jingfeng 9, 29, 4.B

Xu, Liukang 83

Xu, Xiaofeng 175, 4.A, 70, 95

Xue, Huije 179

Xue, Huijie 8.C

Xue, Jianhong 183

Yadav, Vineet 149, 135

Yang, Bai 4.A

Yang, H. 5.A

Yang, Xiaoyuan 134, 86

Yang, Zhiqiang 138, 159, 7.C

Yao, Tian 86

Yavin, Yael G 176

Yeluripati, Jagadeesh 72

Yi, S. 3.B

Yi, Shuhua 49

Young, Stephen L 110

Yuan, Fengming 3.B

Yuan, Wenping 119, 4.A, 160

Zaccheo, T. Scott 6

Zagorac, Nenad 67

Zahariev, Kos 9.A

Zaitchik, Ben 106

Zeng, Fanwei 193 Zeng, Ning 106

Zeri, Marcelo 30 Zha, Tianshan 4.A

Zhang, Chi 175, 70, 95

Zhang, Ke 57, 75

Zhang, Li 142

Zhang, Qingling 134

Zhang, Qingyuan Y. 44

Zhang, Tingjun 64, 9.B, 65

Zhao, Chuanfeng 67, 173

Zhao, Feng 8, 86

Zhao, Shuqing 119, 128

Zheng, Daolan 146 Zhou, Tao 136

Zhou, Xuhui 4.A, 136

Zhu, Zhiliang 13

Zhuang, Qianlai 29

Ziegler, Susan E. 107

Zona, Donatella 83