Testing the flux tower upscaling hypothesis at a regional scale in a complex landscape (NASA-funded project)

Paul Bolstad, Randy Kolka, Mark Kubiske, Faith Ann Heinsch, Ken Davis

• Tier 1 – Modeling (BIOME-BGC), 1 km & 250 m MODIS products, & land cover

• Tier 2 – FIA data from USFS & remotely sensed data (Landsat & MODIS)

• Tier 3 – biomass & soil sampling; soil & leaf gas exchange measurements

• Tier 4 – regional, stand, & mobile tower fluxes

Measurement of fluxes with towers equipped witheddy covariance instrumentations

at two spatial scales

1) Regional levelVery tall tower at WLEF400 m

Results: Region as CO2 source/weak sink

2) Stand level30 m

Results: Forest stand as CO2 sink

Why are these results conflicting?

Mobile eddy covariance and stationary micrometeorological measurements in clearcuts and wetlands – An update

Nick Saliendra

Mark Kubiske

Ron Teclaw

Dan Baumann

USDA Forest Service

North Central Research Station

Ecophysiological Processes Unit

Forestry Sciences Lab

Rhinelander, WI

Two Mobile EC Systems

• 3-D sonic anemometer (CSAT3)• Open path IRGA (LI-7500)• CR5000 data logger• Measurements at 10 Hz• Half-hourly averaging

Five Micrometorological Stations

• PAR (photosynthetically active radiation)• Temperature• Relative humidity• Precipitation• Soil H2O & temperature (clearcuts)• Depth of water table (wetlands)• Half-hourly averaging

Mobile EC sites for Tier 4

Clearcut Sites

Riley Creek (Ameba Salvage)

Thunder Creek

Wetland SitesRiley Creek (Ameba Salvage)

South Fork

Wilson Flowage

Forested Wetland (east of WLEF)

Schedule of mobile flux tower measurements - year 1 (2005) of the NASA project

Date* DoY8-Day Clearcut Sites Wetland Sites

Period Riley Cr. Thunder Cr. Chen1 S. Fork Wilson Fl. Chen2

May 25 - Jun 1 145 1 EC#2  

Jun 2 - 9 153 2 EC#2   EC#1  

Jun 10 - 17 161 3 EC#1 EC#2  

Jun 18 - Jul 25 169 4 EC#2   EC#1  

Jun 26 - Jul 3 177 5 EC#1 EC#2  

Jul 4 - 11 185 6 EC#2   EC#1  

Jul 12 - 19 193 7 EC#1 EC#2  

Jul 20 - 27 201 8 EC#1   EC#2

Jul 28 - Aug 4 209 9 EC#2   EC#1  

Aug 5 - 12 217 10 EC#1 EC#2  

Aug 13 - 20 225 11 EC#2   EC#1  

Aug 21 - 28 233 12 EC#1 EC#2  

Aug 29 - Sep 5 241 13 EC#2   EC#1  

Sep 6 - 13 249 14 EC#1 EC#2  

Sep 14 - 21 257 15 EC#2   EC#1  

Sep 22 - 29 265 16   EC#1   EC#2    

* Date of measurements coincide with the 8-day MODIS compositing periods.