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March 20-23, 2005

Cook Conference Center & Hotel at LSU

Baton Rouge, Louisiana, USA

ABSTRACT BOOK AND PROGRAM

Wetland Biogeochemistry

Institute

Wetland Biogeochemistry

Laboratory

Project #0508

March 20-23, 2005 Baton Rouge, LA, USA

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Welcome to Baton Rouge The Wetland Biogeochemistry Institute of LSU is very excited about hosting the 9th International Symposium on Biogeochemistry of Wetlands, March 20th-23rd, 2005. Ramesh and I welcome your participation to this very exciting symposium gathering. This book will help you plan your attendance at the symposium. For the most up-to-date information please check the on-site registration desk in the lobby of the LSU Cook Conference Center. The objective of this international symposium is to provide a framework for scientists to discuss new topics related to biogeochemistry of nutrients and other contaminants in freshwater and coastal wetlands. The focus of the symposium will be on new approaches and techniques that control the fate of chemicals at the local, regional and global scale. Wetland ecosystems serve as sinks, sources, and transformers of nutrients and other chemical contaminants, and as such they can have a significant impact on water quality and ecosystem productivity. The primary driver of these processes is the ecosystem biogeochemistry, which includes chemical, biological and physical processes in the soil and water column. Often, these processes are lumped and the ecosystem is treated as a "black box" and a simplified input-output analysis is used to address water quality issues. This traditional empirical approach is inadequate for effective evaluation of an ecosystem's performance, and new techniques and methodologies are being developed to improve our understanding of local, regional and global patterns of community structure and ecosystem function. Biogeochemistry is an interdisciplinary science, which includes the study of interactive biological, geological and chemical processes regulating the fate and transport of nutrients and contaminants in soil, water and atmospheric components of an ecosystem. Biogeochemistry also provides a framework to integrate physical, chemical and biological processes functioning in an ecosystem at various spatial and temporal scales. We hope that you enjoy your visit with us here at the Wetland Biogeochemistry Institute of LSU. While we dedicate this symposium to our friend and colleague, Dr. William Patrick, Jr., we also look to the future of the significance of wetland biogeochemistry to solving some of our most urgent environmental problems. This is a tribute to the vision that Bill established several decades ago; we are confidant that it will have a lasting effect on the growth of our discipline. Respectfully yours, Steering Committee Co-Chairs: Robert R. Twilley K. Ramesh Reddy Wetland Biogeochemistry Institute Soil and Water Science Department Dept. of Oceanography & Coastal Science Institute of Food & Agricultural Science Louisiana State University University of Florida [email protected] [email protected]

9th International Symposium on Biogeochemistry of Wetlands

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Table of Contents

Welcome Letter.................................................................................... i

Symposium Planning Committee..................................................... iv

Symposium Sponsor ........................................................................... v

Cook Conference Center Map & Information ............................... vi

Program Description ........................................................................ vii

Speaker & Poster Presenter Information ..................................... viii

Symposium Social Events ................................................................. ix

Program Agenda................................................................................. x

Poster Session I Directory.............................................................. xxv

Poster Session II Directory ........................................................... xxix

Symposium Abstracts......................................................................... 1 Author Index ................................................................................... 119

Notes................................................................................................. 122


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Symposium Planning Committee Symposium Organizers Dr. Robert R. Twilley, Symposium Co-chair Wetland Biogeochemistry Institute Department of Oceanography and Coastal Science Louisiana State University Baton Rouge, LA 70803 PHONE (1): 225-578-8806 PHONE (2): 225-578-6431 FAX: 225-578-6423 EMAIL: [email protected] WEBSITE: http://www.wetlandbiogeochemistry.lsu.edu/ Dr. K. R. Reddy, Symposium Co-chair Soil and Water Science Department Wetland Biogeochemistry Laboratory Institute of Food & Agricultural Science University of Florida PO Box 110510 Gainesville, FL 32611 PHONE: 1-352-392-1804 FAX: 1-352-392-3399 EMAIL: [email protected] WEBSITE: http://soils.ifas.ufl.edu/ Symposium Coordinator Tracy Nininger, Symposium Coordinator University of Florida / IFAS Office of Conferences and Institutes (OCI) P.O. Box 110750, Mowry Road Building 639 Gainesville, FL 32611-0750, USA PHONE: 1-352-392-5930 FAX: 1-352-392-9734 EMAIL: [email protected] WEBSITE: http://conference.ifas.ufl.edu/wetlands/index.html


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Symposium Sponsor

Special Thanks to Our Symposium Sponsor:

This symposium would not be possible without the financial support of a donation by BP to the School of the Coast and Environment (SCE). This donation was part of a contribution to SCE to support knowledge in the restoration of coastal Louisiana. The symposium co-chairs and the LSU School of the Coast and Environment thank BP for their generous support of this professional symposium.


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Cook Conference Center Map & Information

Cook Conference Center and Hotel at LSU

3848 W Lakeshore Dr. Baton Rouge, LA 70808-4600

Toll Free (866) 610-2665 Phone: (225) 383-2665 Fax: (225) 383-4200

Located on the campus of Louisiana State University, just off I-10 and Dalrymple Drive.

Rooms: Available for check-in on the day of arrival after 3:00pm. Checkout is at 12:00 noon. If you are arriving early or leaving late, the hotel has a secured baggage area.

Parking: Parking is available at the Cook Conference Center at no extra charge.

Complimentary Breakfast: Guests can start each day by enjoying a complimentary full breakfast served in the Shaquille O’Neal Lodge.

Printing, Computer, Fax, Photocopying services: The hotel offers a business center equipped with computer, copier and phone.

Message Board: There is a message board posted near the registration desk in the lobby of the Cook Conference Center for participant use.

Food Service: Breakfast is complimentary to those staying as a guest at the Cook Conference Center & Hotel. Daily morning, mid-day and afternoon refreshments are offered as well as a box lunch on Monday and Tuesday. The Sunday Welcome Reception and the Monday evening Poster Session & Reception will include heavy hors d'oeuvres and refreshments, while the Tuesday Symposium Dinner Banquet is a complete meal.

The Tiger Lair Food Court (Various foods available including a pasta bar, Louisiana-style home cooking, fried chicken and several chain restaurants including Pizza Hut, Chick filet, etc.) will be open from 7:00am-2:00pm in the LSU Union. Other restaurants within walking distance from the LSU campus include; Chimes Restaurant, Serrano's Salsa Company, Chelsea's Café, McDonald's, Subway, Wendy's, Jack in the Box, Silver Moon, and CJ's Sandwich Shop. Inquire at the registration desk for locations and directions.

Emergency phone number: Phone number at the Cook Conference Center and Hotel is Phone: (225)-383- 2665. Please advise the hotel desk that the message is for a participant of the Wetland Symposium.


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Program Description Plenary Sessions: The 9th International Symposium on Biogeochemistry of Wetlands will begin with a plenary session each morning. On Monday, 21 March, the symposium will begin in a plenary session at 8:00 a.m. in Laborde Hall of the Cook Conference Center. The Plenary will include a short welcome from the Symposium co-chairs, a welcome from Dr. William Jenkins, President of the LSU System, followed by a series of presentations in honor of the late Dr. William Patrick. On Tuesday and Wednesday, the plenary sessions will begin at 8:30 am in the Laborde Hall of the Cook Conference Center Concurrent Sessions: Oral Sessions of the 9th International Symposium on Biogeochemistry of Wetlands will include blocks of five 20-minute presentations in different arrangements of concurrent sessions. This time schedule of the symposium will be strictly adhered to by the session chairs and is designed for a fifteen-minute presentation leaving ample time for follow-up questions, discussions, and speaker changeover. During most of the symposium, there are two concurrent sessions held in Laborde Hall and Abell Hall of the Cook Conference Center. On Monday afternoon there is a third concurrent session that will be held in the Cook Conference Room. See the program agenda for the schedule of oral presentations. Monday Poster Session: The Monday poster session and reception will be held at the School of the Coast and Environment (Energy, Coast and Environment Building) in the Rotunda Conference Room & Auditorium from 5:00 p.m. to 7:00 p.m. A tour of the Wetland Biogeochemistry Institute’s facilities, located in the School of the Coast and Environment building, will be given during the Monday Reception, starting at 5:00 p.m. Tuesday Poster Session: The Tuesday poster session will be held in the Abell Conference Room of the Cook Conference Center from 5:00 p.m. to 7:00 p.m. Directly following the poster session will be the Symposium Banquet in the Laborde Hall of the Cook Conference Center.


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Speaker & Poster Presenter Information Speaker Instructions for PowerPoint Presentations: LCD equipment is available in each room for PowerPoint presentations. The symposium will assume that all oral presentations will use PowerPoint slides unless otherwise notified to the symposium co-chairs. Speakers should also introduce themselves to the session chair during the break before the scheduled presentation. Procedure to loading presentation files is as follows:

(1) Preference is that a presentation file is burned on CD and turned into the REGISTRATION DESK at the time of registration; or no later than the evening prior to the presentation. The registration desk will make sure that the file is delivered to the appropriate room and computer. All files will be checked by the room monitor for presentation quality once loaded unto the appropriate computer. You should contact the room monitor during the break PRIOR to your presentation to make sure that your presentation file is properly formatted.

(2) You may also load your presentation directly on the appropriate computer using a memory key. This method requires that you contact the Room Monitor directly and have the file loaded on the appropriate computer. The file can be checked for presentation quality at that time. All computer and LCD systems will use PC systems. Macintosh presentations should be loaded using the most recent versions of Microsoft PowerPoint to minimize problems; or burn onto disk using hybrid-formatting procedures.

(3) There will not be a pre-presentation room for checking file quality; this will have to be done directly on the computer that the presentation will be shown. Thus it is recommended that presentation be loaded early enough to check for problems at the minimum of one break before your presentation.

Poster Presenter Instructions: Each presenter will be provided a poster mounting board that is white in color and measures maximum of 4 ft wide x 3 ft high. Posters must be presented to the poster monitor located in the Anderson Conference Room of the Cook Conference Center by lunch break the day of the poster presentation. The poster monitor will assist the presenter in mounting the poster on a poster foam board that will be provided by the symposium. Each poster board will have a number, and the presenter should make sure that the poster is mounted on the appropriate poster board (see the poster directory for assigned number). Symposium staff and the poster monitor will make sure that the poster boards are set up in the appropriate location during the Poster Session (Monday in the Energy, Coast and Environment building; and Tuesday in the Abell Conference Room of Cook Conference Center). Posters will be returned to the Anderson Conference Room the following morning; and should be picked up by the Presenter by the morning break. Presenters should be present at their poster during the assigned time of the poster session to answer questions.


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Symposium Social Events

Sunday, 20 March, 2005 Welcome & Co-Chair Reception at Cook Conference Center: Be sure to arrive in Baton Rouge in time for our symposium opener. With the support of British Petroleum, WBI is pleased to host this opening reception at the Cook Conference Center. 6:00 pm-8:00 pm Monday, 21 March, 2005 WBI Reception and Memorial to Dr. William Patrick: A tour of the Wetland Biogeochemistry Institute’s facilities, located in the School of the Coast and Environment building, will be given during the Monday Reception and Poster Session. A short ceremony dedicating the WBI Library will be held in the Auditorium at 5:00 p.m., followed by the poster session and tour of WBI facilities. 5:00 pm-7:00 pm The School of the Coast and Environment at LSU exists to provide knowledge, technology, and human resources for successful management of natural resources and resolution of environmental issues important to Louisiana, the Gulf of Mexico region, and comparable areas throughout the nation and the world. They, together with scientists in the Coastal Ecology Institute and the Wetland Biogeochemistry Institute, provide expert assistance for the management, restoration, and preservation of Louisiana's invaluable coastal wetlands. http://www.sc&e.lsu.edu/ Tuesday, 22 March, 2005 Symposium Banquet: The symposium banquet will be held on Tuesday evening in the Laborde Hall of the Cook Conference Center starting at 7:30 p.m., following the poster session in the Abell Conference Room from 5:00 p.m.- 7:00 p.m. The banquet is part of the symposium registration fee. 7:30 pm-9:00 pm


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Program Agenda Abstract page numbers are indicated at the end of listings when applicable [example: “…(p. 2)”]

Sunday, March 20, 2005

4:00pm-8:00pm Registration – Lobby of Cook Conference Center

5:00pm-7:00pm Poster set-up – Anderson Conference Room of Cook Conference Center

6:00pm-8:00pm Welcome & Co-Chair Reception (Sponsored by British Petroleum)

Monday, March 21, 2005

7:30am-5:00pm Registration – Lobby of Cook Conference Center

PLENARY SESSION I - LABORDE HALL, COOK CONFERENCE CENTER Session Chair: Robert Twilley

8:00am-8:15am Symposium Opening & Welcome – Robert Twilley, Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Louisiana State University

8:15am-8:30am Welcome to Louisiana State University – William Jenkins, President of the LSU System

8:30am-8:55am Biogeochemistry of Wetland Soils: A Review of Five Decades of Research – K. R. Reddy1 and R. D. Delaune2; 1Wetland Biogeochemistry Laboratory; Soil and Water Science Department, University of Florida, Gainesville, FL; 2Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA................ (p. 88)

8:55am-9:20am Phosphorus, Patrick and Polemics – Curtis J. Richardson; Duke University Wetland Center, Nicholas School of the Environment and Earth Sciences, Durham, NC ................................................................. (p. 91)

9:20am-9:50am Greenhouse Gases and Experiences with Bill Patrick – O. Van Cleemput and P. Boeckx; Laboratory of Applied Physical chemistry (ISOFYS), Faculty of Bioscience Engineering, Ghent University, Belgium...................................................................................................... (p. 108)

9:50am-10:20am BREAK


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Monday, March 21, 2005 (continued)

SESSION B1: TREATMENT OF AGRICULTURAL RUNOFF IN CONSTRUCTED AND NATURALWETLANDS - LABORDE HALL

Session Chair: John R. White

10:20am-10:40am Strategic Restoration of Wetlands on Private Lands: Regional Approaches in the Lake Okeechobee Watershed – Patrick J. Bohlen1, Stanley Gathumbi1, Kathleen McKee2, Mark Clark2 and Sabine Grunwald2; 1Archbold Biological Station, MacArthur Agro-Ecology Research Center, Lake Placid, FL; 2University of Florida, Soil and Water Science, Gainesville, FL.............................................. (p. 8)

10:40am-11:00am ReCiprocating Constructed Wetlands for Treating High Strength Anaerobic Lagoon Wastewater – Leslie Behrends, E. Bailey, W. Ellison, L. Houke, P. Jansen, C. Shea, S. Smith and T. Yost; Tennessee Valley Authority, Department of Air Land and Water Sciences, Muscle Shoals, AL, USA.......................................... (p. 4)

11:00am-11:20am Performance of Stormwater Treatment Wetlands Receiving Low Phosphorus Agricultural Drainage Water: Implications for Design and Management – John R. White1, K. Ramesh Reddy2 and Jana.Majer Newman3; 1Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA; 2Soil and Water Science Department, University of Florida, Gainesville, FL; 3Everglades Division, South Florida Water Management District, West Palm Beach, FL ............................................................................ (p. 112)

11:20am-11:40am Effects of Co-Occurring Agricultural Pollutants on Nitrogen Removal by a Constructed Coastal Wetland – Michael F. Piehler1, Sara W. McMillan1, Suzanne P. Thompson1 and Amy C. Poe2; 1UNC Chapel Hill Institute of Marine Sciences, Morehead City, NC; 2Janicki Environmental, St Petersburg, FL.................... (p. 82)

11:40am-12:00pm The Use of Mangrove Forests to Treat Shrimp Ponds Effluents in the Neotropics: Current Issues and Viability – V. H. Rivera-Monroy1, D. Gauthier 2, R. R. Twilley1, J. W. Day3, E. Castaneda1 and H. Corrales2; 1Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana USA; 2Granjas Marinas San Bernardo, Choluteca, Honduras; 3Coastal Ecology Institute, Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana USA ............................................................... (p. 93)


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SESSION B2: TRACE ELEMENTS - ABELL HALL Session Chair: Robert P. Gambrell

10:20am-10:40am The Role of Wetland Trees in Element Cycling and Dispersal, Sky Lake, Mississippi – Stan Galicki1, Gregg R. Davidson2 and Stephen R. Threlkeld3; 1Department of Geology, Millsaps College, Jackson, MS; 2Department of Geology and Geological Engineering, University of Mississippi, University, MS; 3Department of Biology, University of Mississippi, University, MS ........................................ (p. 39)

10:40am-11:00am Fate of Long-lived Artificial Radionuclides in Standing Aquatic Ecosystems of the Chernobyl Exclusion Zone – D. Gudkov1, A. Kulachinsky2, A. Nazarov2, L. Zub3, V. Mashina1 and A. Savitsky4; 1Institute of Hydrobiology, Kiev, Ukraine; 2State Specialised Research Enterprise “Chernobyl Radioecological Centre”, Chernobyl, Ukraine; 3Shmalgauzen Institute of Zoology, Kiev, Ukraine; 4Kholodny Institute of Botany, Kiev, Ukraine................ (p. 46)

11:00am-11:20am Heavy Metals in Phragmites australis and Phalaris arundinacea Growing in Constructed Wetlands Treating Municipal Sewage – J. Vymazal1, J. Svehla2 and V. Chrastny2; 1ENKI o.p.s, Trebon, Czech Republic; 2University of South Bohemia, Department of Chemistry, Ceske Budejovice, Czech Republic ............................. (p. 111)

11:20am-11:40am Factors Affecting Metal Mobility and Bioavailability in Intertidal Sediments of the Scheldt Estuary – G. Du Laing, D. Vanthuyne, F. M. G. Tack and M. G. Verloo; Ghent University, Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent, Belgium.......................................................................................... (p. 34)

12:00am-1:00pm BOX LUNCH PROVIDED


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SESSION C1: TREATMENT OF MUNICIPAL WASTEWATER IN CONSTRUCTED AND NATURAL WETLANDS - LABORDE HALL

Session Chair: Marco Belmont

1:00pm-1:20pm Assessing Trace Metal Accumulation in a Constructed Wetland Receiving Domestic Wastewater – Els Lesage1, D.P.L. Rousseau2, F.M.G. Tack1, M.G. Verloo1 and N. De Pauw2; 1Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent, Belgium; 2Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent, Belgium.......................................................................................... (p. 60)

1:20pm-1:40pm Rejuvenating the Largest Municipal Treatment Wetland in Florida – H. Wang1, J.W. Jawitz1, J.R. White2 and M. D. Sees3; 1Soil and Water Science Department, University of Florida, Gainesville, FL; 2Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA; 3City of Orlando, Public Works Department, Bureau of Waste Water, Orlando, FL ................................................. (p. 52)

1:40pm-2:00pm Biotreatment of Municipal Wastewater with Constructed Wetlands at Oahu, Hawaii – P. A. Pier, R. A. Almond and L. L. Behrends; Tennessee Valley Authority, Muscle Shoals, AL ................................................................................... (p. 83)

2:00pm-2:20pm A Review of Wetland Waste Water Assimilation in the Louisiana Coastal Zone – John Day; Dept. of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA .............. (p. 27)

2:20pm-2:40pm Presence of Pharmaceuticals in a Large Treatment Wetland in Florida, USA – Marco A. Belmont1, John R. White1 and Chris D. Metcalfe2; 1 Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA, USA; 2 Water Quality Centre, Trent University, Peterborough, Ontario, Canada ........................................ (p. 7)

2:40pm-3:00pm BREAK


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SESSION C2: BIOGEOCHEMISTRY OF INTERNATIONAL WETLAND SYSTEMS- ABELL HALL Session Chair: Victor H. Rivera-Monroy

1:00pm-1:20pm The Biodiversity of Lake Victoria Wetlands: Case Study of the Giant Yala Swamp, Nyando and Sondu-Miriu Wetlands, Kenya – John Vorster1 and Judith Akinyi Omollo2; 1Research Assistant, VIRED Int’l, Kisumu, Kenya; 2Environmental Educator, C/O Yago Primary School, Suna-Migori, Kenya ............................................... (p. 110)

1:20pm-1:40pm Coupling Oligotrophy and Peat Development in a Coastal Freshwater Swamp of Panamá – T. Troxler-Gann and D. Childers; Florida International University, Department of Biological Sciences and Southeast Environmental Research Center, Miami, FL.................................................................................................. (p. 107)

1:40pm-2:00pm An Assessment of the Human Impact on a Tropical Coastal Wetland Ecosystem – K. Shadananan Nair; Centre for Earth Research & Environment Management, Vaikom, Kerala, India . (p. 73)

2:00pm-2:20pm Activity and Controls of Methanogenesis in Catotelm of Acid Peatlands from Central Russia – I. Kravchenko1 and A. Sirin2; 1Winogradsky Institute of Microbiology RAS, Moscow, Russia; 2Institute of Forest Science RAS, Moscow Region, Russia.......... (p. 56)

2:20pm-2:40pm Seasonal Nitrogen Dynamics in the Pichavaram Mangrove Forest, India – M. Bala Krishna Prasad and AL. Ramanathan; School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India ....................................................................................... (p. 85)

2:40pm-3:00pm BREAK


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SESSION D1: OVERVIEWS OF TREATMENT WETLANDS - LABORDE HALL Session Chair: Stephen Davis

3:00pm-3:20pm Meeting the Challenge of Meshing Dual Roles for Stormwater Treatment Areas in South Florida – Jana Majer Newman; Everglades Division, South Florida Water Management District, West Palm Beach, FL .............................................................................. (p. 75)

3:20pm-3:40pm Stormwater Treatment Areas for Everglades Protection: Capabilities and Limitations – Thomas A. DeBusk, John Juston and Forrest E. Dierberg; DB Environmental, Inc., Rockledge, FL............................................................................................ (p. 29)

3:40pm-4:00pm Forested Wetland Dynamics Receiving Treated Municipal Wastewater: Nutrient Interactions and Forest Productivity – Christopher G. Brantley and John W. Day, Jr.; Department of Oceanography and Coastal Sciences, School of the Coast and Environment, Louisiana State University, Baton Rouge, LA...... (p. 12)

4:00pm-4:20pm Screening Aquatic Plants for Nitrate Removal Potential – Leslie L Behrends, E. Bailey, L Houck, P. Jansen, P. Pier and T. Yost; Department of Air Land and Water Sciences, Tennessee Valley Authority, Muscle Shoals, AL USA...................................................... (p. 6)

4:20pm-4:40pm Losses of Nitrogen Through Various Mechanisms Under Flooded Rice Eco-System – D. K. Das and Pintu Sur; Department of Agricultural Chemistry & Soil Science, Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal, India..................................... (p. 25)


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SESSION D2: LANDSCAPE PATTERNS OF BIOGEOCHEMICAL PROCESSES - ABELL HALL Session Chair: Patrick Megonigal

3:00pm-3:20pm Geostatistical Analyses of Soils Data from Water Conservation Area 3, South Florida – Gregory L. Bruland1, Sabine Grunwald1, Todd Z. Osborne1, K. Ramesh Reddy1 and Sue Newman2; 1University of Florida/IFAS, Soil and Water Science Department, Gainesville, FL; 2South Florida Water Management District, West Palm Beach, FL.......................................................................................... (p. 13)

3:20pm-3:40pm Primary Production and Respiration Rates of Microbial Mats in an Oceanic Mangrove Ecosystem – Rosalynn Y. Lee, Samantha B. Joye and Christof Meile; University of Georgia, Department of Marine Sciences, Athens, GA, USA.................................................... (p. 59)

3:40pm-4:00pm Wetland Macrophyte Decomposition under Different Nutrient Conditions: What Is More Important, Litter Quality or Site Quality? – Eliška Rejmánková1, Dagmara Sirová2 and Kateřina Houdková2; 1University of California Davis, One Shields Ave., Davis, CA USA; 2Faculty of Biological Sciences, University of South Bohemia, České Budějovice, Czech Republic ..................... (p. 89)

4:00pm-4:20pm Landscape Level Assessment of Nutrient Limitation Using Plant Tissue Nutrient Ratios – R. J. Daoust1,4, C. T. Nietch2, C. S. Hopkinson3 and J. T. Morris1; 1Department of Biological Sciences, University of South Carolina, Columbia, SC, USA; 2Water Quality Monitoring Branch, US Environmental Protection Agency, Cincinnati, OH, USA; 3Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA, USA; 4current address: BEM Systems, Inc., West Palm Beach, FL, USA....................................... (p. 24)

4:20pm-4:40pm Soil Nutrient Dynamics in Coastal Wetlands across a Saltwater-Freshwater Continuum on the Logan River Floodplain, South-East Queensland, Australia – Margaret Greenway; School of Environmental Engineering, Griffith University and Cooperative Research Centre for Coastal Zone, Estuary and Waterway Management, Brisbane, Queensland, Australia................................ (p. 43)


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SESSION D3: ORGANIC MATTER AND PRIMARY PRODUCTION - COOK CONFERENCE ROOM Session Chair: Sue Newman

3:00pm-3:20pm Gas Exchange Responses of Black Willow (Salix nigra) Cuttings to a Range of Soil Moisture Regimes – S. Li1, S. R. Pezeshki1, S. Goodwin2 and F. D. Shields, Jr.3; 1Department of Biology, The University of Memphis, Memphis, TN, USA; 2W. Harry Feinstone Center for Genomic Research, The University of Memphis, Memphis, TN, USA; 3USDA-ARS National Sedimentation Laboratory, Oxford, MS, USA.............................................................. (p. 62)

3:20pm-3:40pm Seasonal and Geomorphological Variability of the Quantity and Quality of Dissolved Organic Matter (DOM) in the Florida Coastal Everglades – Nagamitsu Maie, Kathleen Parish and Rudolf Jaffé; Department of Chemistry & Biochemistry, and Southeast Environmental Research Center, Florida International University, Miami, FL USA......................................................................................... (p. 65)

3:40pm-4:00pm Changes In Humic Acid Type In Cowdung And Poultry Manure Amended Wetland Soils – F. Rahman, U. A. Naher, A. T. M. S. Hossian, M. A. Saleque and M. A. M. Miah; Soil Science Division, Bangladesh Rice Research Institute, Gazipur, Bangladesh .......... (p. 87)

4:00pm-4:20pm Organic Matter and Amino Acids in Wetlandsoils – J. Omote; Environmental Eco Technology Institute, Tokyo & Kinki University Technical College, Department of Architecture and Civil Engineering, Mie, Japan.......................................................................... (p. 79)

SOCIAL EVENTS AND POSTER SESSION – ENERGY COAST AND ENVIRONMENTAL BUILDING

5:00pm-5:30pm WBI Library Dedication Ceremony - Rotunda Conference Room & Auditorium

5:00pm-7:00pm Poster Session I & WBI Reception - Memorial to Dr. William Patrick - Rotunda Conference Room & Auditorium

5:00pm-7:00pm Tour of the Wetland Biogeochemistry Institute’s Facilities


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Tuesday, March 22, 2005

7:30am-5:00pm Registration – Lobby of Cook Conference Center

PLENARY SESSION II - LABORDE HALL, COOK CONFERENCE CENTER Session Chair: Curtis Richardson

8:30am-9:10am Benthic Microbial Mats: Important Sources Of Fixed Nitrogen And Carbon in Mangrove Wetlands – Samantha B. Joye; University of Georgia, Department of Marine Sciences, Athens, GA, USA............................................................................................................... (p. 53)

9:10am-9:50am Regulation of Salt Marsh Primary Production, Geomorphology and Biogeochemical Cycles by Variation in Mean Sea Level – James T. Morris; University of South Carolina, Department of Biological Sciences, Columbia, SC, USA ......................................... (p. 71)


SESSION B1: CONTROLS OF NUTRIENT REMOVAL - ABELL HALL Session Chair: Jos T. A. Verhoeven

10:20am-10:40am Effect of Macrophyte Diversity and Community Composition on Carbon and Nitrogen Cycles: An Experimental Study in Mesocosm – Virginie Bouchard1, Serita Frey2, Janice Gilbert1 and Sharon Reed1; 1School of Natural Resources, Ohio State University; 2Department of Natural Resources, University of New Hampshire ......................................................................................... (p. 11)

10:40am-11:00am Vegetation and Sediment Gradients in Wetland Mesocosms Used for Low-Level Phosphorus Removal – Michelle Kharbanda, Thomas A. DeBusk, Forrest E. Dierberg and Scott D. Jackson; DB Environmental, Inc., Rockledge, FL............................................ (p. 55)

11:00am-11:20am Wetland N and P Dynamics along a Gradient of Vegetation Productivity and Soil pH – R. Merckx1 and M. Drouillon2; 1Catholic University of Leuven, Lab for Soil and Water Management, Heverlee, Belgium; 2Hogeschool West-Vlaanderen, Department of Industrial Engineering and Technology, Kortrijk, Belgium........................................................................................................ (p. 33)

11:20am-11:40am Effects of Vegetation Type on Soil Accrual and Phosphorus Stability in Wetlands Receiving Agricultural Drainage – Kevin A. Grace1, Forrest E. Dierberg1 and John R. White2; 1DB Environmental, Inc., Rockledge, FL; 2Wetlands Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA................ (p. 42)

11:40am-12:00pm Phenol Oxidase as a Regulator of Atmospheric Carbon Sequestration and Bioremediation in Wetlands – Chris Freeman; School of Biological Sciences, University of Wales, Bangor, UK ................................................................................................. (p. 38)


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Tuesday, March 22, 2005 (continued)

SESSION B2: ECOSYSTEM STRUCTURE AND FUNCTION - LABORDE HALL Session Chair: Christopher Craft

10:20am-10:40am Development of Heterotrophic Microbial Processes and Food Webs Following Salt Marsh Creation – C. Craft1 and J. P. Megonigal2; 1School of Public and Environmental Affairs, Indiana University, Bloomington, IN, USA; 2 Smithsonian Environmental Research Laboratory, Edgewater, MD, USA ...... (p. 21)

10:40am-11:00am Phosphorus Sorption Capacity and Exchange by Soils from Mitigated and Late Successional Bottomland Forest Wetlands – E. M. D'Angelo1, A. D. Karathanasis1 and E. J. Sparks2; 1Soil and Water Biogeochemistry Lab, Horticulture, Plant, and Soil Science Department, University of Kentucky, Lexington, KY, USA; 2US Army Corps of Engineers, Eastern Kentucky Regulatory Office, KY, USA ..................................................................................................... (p. 23)

11:00am-11:20am Marsh Plant Growth Response and Metal Uptake from Amended Red Mud Substrates in Greenhouse and Field Studies – Robert P. Gambrell1, Cale LeBlanc2, Norman Murray3 and Lorna Putnam1; 1Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA; 2Conestoga-Rover and Associates, Baton Rouge, LA; 3Norman Murray and Associates, Covington, LA ........................................................................................... (p. 40)

11:20am-11:40am Phosphorus Enrichment and Restoration of the Everglades – S. Newman1, P. V. McCormick2, K. R. Reddy3 and B. L. Turner4; 1Everglades Division, South Florida Water Management District, West Palm Beach, FL, USA; 2Leetown Science Center, U.S. Geological Survey, Kearneysville, WV, USA; 3Wetland Biogeochemistry Laboratory, Soil and Water Science Department, University of Florida, Gainesville, FL, USA; 4 Smithsonian Tropical Research Institute, Balboa, Ancon, Republic of Panama.............. (p. 76)

1:40am-12:00pm Chemical Speciation of Phosphorus as an Index of Alterations in Ecosystem Structure and Function – Curtis J. Richardson1, P. V. Sundareshwar2 , Wyatt H. Hartman2 and Greg. L. Bruland3; 1Duke University Wetland Center, Nicholas School of the Environment and Earth Sciences, Durham, NC; 2Institute of Atmospheric Sciences, South Dakota School of Mines, Rapid City, SD; 3University of Florida, Soil and Water Science Department, Institute of Food and Agricultural Sciences, Gainesville, FL...... (p. 90)

12:00-1:00p.m. BOX LUNCH PROVIDED


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SESSION C1: TECHNIQUES IN BIOGEOCHEMISTRY - ABELL HALL Session Chair: Greg Bruland

1:00pm-1:20pm Preliminary Evaluation of a Laboratory Scale Wastewater Treatment by Constructed Subsurface Flow Wetlands Planted with Ornamental Plants of Commercial Interest – F. Zurita1, J. de Anda2, Y. Herrera1 and V. Delgado1; 1Centro Universitario de la Ciénega. UdeG. México; 2Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, México..................... (p. 118)

1:20pm-1:40pm Phosphorous Sequestration Using Al-containing Amendments in Organic Soils from a Municipal Wastewater Treatment Wetland – John R. White1 and Lynette M. Malecki2; 1Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, USA; 2Wetlands Biogeochemistry Laboratory, Soil and Water Science Department, University of Florida, Gainesville, FL, USA ........... (p. 66)

1:40pm-2:00pm Inference of Phosphorus Sorption Capacity in Southeastern Wetland Soils using Near Infrared Reflectance Spectroscopy (NIRS) – Matthew Cohen, Mark Clark, Jeremy Paris and K. Ramesh Reddy; University of Florida, Wetland Biogeochemistry Laboratory, Soil and Water Science Department, Gainesville FL, USA............................................................................................................... (p. 20)

2:00pm-2:20pm An Evaluation of Two Tracers Commonly Applied to Surface-Flow Wetlands: Rhodamine-WT and Lithium – Forrest E. Dierberg and Thomas A. DeBusk; DB Environmental, Inc., Rockledge, FL ............................................................................................ (p. 31)

2:20pm-2:40pm Population Genetic Structure of Rhizophora stylosa (Griff.) in Sakishima Islands, Japan Based on Variation at Nuclear and Chloroplast Microsatellite (SSR) Loci – Md. Sajedul Islam1, Chunlan Lian2, Norikazu Kameyama3, Bingyun Wu1 and Taizo Hogetsu1; 1Graduate School of Agriculture and Life Sciences, the University of Tokyo, Japan; 2Asian Natural Environmental Science Center, the University of Tokyo, Japan; 3Faculty of Agriculture, University of the Ryukyus, Japan......................................................... (p. 50)

2:40pm-3:00pm BREAK


xxi


SESSION C2: BIOGEOCHEMICAL PATTERNS OF PULSED ECOSYSTEMS - LABORDE HALL Session Chair: Patrick Bohlen

1:00pm-1:20pm The Effect of the Caernarvon Freshwater Diversion on Water Quality in the Breton Sound Estuary – Robert R. Lane1, John W. Day1,2, Emily Hyfield1,2 and Jason N. Day1; 1Coastal Ecology Institute, Louisiana State University, Baton Rouge, LA; 2Department of Oceanography and Coastal Science, Louisiana State University, Baton Rouge, LA ...................................................................................... (p. 58)

1:20pm-1:40pm Freshwater and Nutrient Inputs to a Mississippi River Deltaic Estuary with River Re-Introduction – Emily C.G. Hyfield1, John W. Day1,2, Jaye E. Cable1,2 and Dubravko Justic1,2; 1Coastal Ecology Institute, Louisiana State University, Baton Rouge, LA; 2

Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA................................................................ (p. 49)

1:40pm-2:00pm Pelagic and Benthic Nutrient Conversions in a Coastal Watershed Influenced by River Diversions (Caernarvon, Louisiana) – J. J. Rick1, S. Rick1 and R. R. Twilley2; 1University of Louisiana at Lafayette, Department of Biology, Lafayette, LA, USA; 2Louisiana State University, Department of Oceanography and Coastal Science, Wetland Biogeochemistry Institute, Baton Rouge, LA, USA...................................................................................................... (p. 92)

2:00pm-2:20pm Influence Of Freshwater Diversions And Drought On Peat and Porewater Sulfur Dynamics in Coastal Louisiana Peat Marshes – C. M. Swarzenski1, T.W. Doyle2 and B. Fry3; 1United States Geological Survey, Baton Rouge, LA, USA; 2United States Geological Survey, Lafayette, LA, USA; 3Coastal Ecology Institute, Louisiana State University, Baton Rouge, LA, USA ................... (p. 101)

2:20pm-2:40pm Factors Affecting Tidal Creek Hydrodynamics and Materials Exchange Between Salt Marshes and Adjacent Bays of the Guadalupe Estuary (TX) – Stephen E. Davis, III1 and J. Bryan Allison2; 1Department of Wildlife & Fisheries Sciences, Texas A&M University, College Station, TX; 2Department of Geology & Geophysics, Texas A&M University, College Station, TX.......... (p. 26)

2:40pm-3:00pm BREAK


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SESSION D1: THEMATIC SESSION OF 9TH INTERNATIONAL SYMPOSIUM - LABORDE HALL Session Chair: Robert Twilley

3:00pm-3:20pm Role of Phosphorus in Assessing Ecosystem Response to Anthropogenic Impact and Global Environmental Change Studies – P. V. Sundareshwar1, Eric Koepfler2 and C. J. Richardson3; 1Center for Biocomplexity Studies, Institute of Atmospheric Sciences, South Dakota School of Mines and Technology, Institute of Atmospheric Sciences, Rapid City, SD; 2Coastal Carolina University; 3Duke University Wetland Center, Duke University, Durham, NC.............................................................. (p. 99)

3:20pm-3:40pm Incorporating Socio-ecological Considerations into Environmental Restoration Efforts: Examples from the Florida Everglades – D. L. Childers; Department of Biological Sciences and SERC, Florida International University, Miami FL................ (p. 18)

3:40pm-4:00pm Contribution of Benthic Mats to Vertical Accretion and Deposition of C and N in Caribbean Mangrove Forests – Karen L. McKee1 and Samantha B. Joye2; 1National Wetlands Research Center-USGS, Lafayette, LA, USA; 2University of Georgia, Athens, GA, USA...................................................................................................... (p. 67)

4:00pm-4:20pm Recent Discoveries of Surprising Anaerobic Organisms and Novel Pathways – J. Patrick Megonigal; Smithsonian Environmental Research Center, Edgewater, Maryland, USA.... (p. 69)

4:20pm-4:40pm Wetlands and Water Quality: A Landscape Perspective – J. T. A. Verhoeven1, B. Arheimer2, Chengqing Yin3 and M. M. Hefting1; 1Landscape Ecology, Utrecht University, The Netherlands; 2Swedish Meteorological and Hydrological Institute, Stockholm, Sweden; 3Chinese Academy of Science, Beijing, PR China .................................................................................................... (p. 109)

SOCIAL EVENTS AND POSTER SESSION – COOK CONFERENCE CENTER

5:00pm-7:00pm Poster Session II - Abell Room

7:30pm-9:00pm Symposium Banquet - Laborde Hall


xxiii

Wednesday, March 23, 2005

PLENARY SESSION III - LABORDE HALL, COOK CONFERENCE CENTER Session Chair: K. Ramesh Reddy

8:30am-9:10am Functional Assessment of Biogeochemistry: Conceptual Models Based on North American Wetlands – Mark M. Brinson; Biology Department, East Carolina University, Greenville, North Carolina

9:10am-9:50am Functional Assessment of Biogeochemistry: Conceptual Models Based on European Wetlands – Edward Maltby; Director, Institute for Sustainable Water, Intergrated Management & Ecosystem Research (SWIMMER), University of Liverpool


SESSION B1: NUTRIENT REMOVAL TECHNIQUES - ABELL HALL, COOK CONFERENCE CENTER Session Chair: Eliska Rejmánková

10:20am-10:40am Comparison of Phosphorus Removal by Two Submerged Plants: The Invasive, Exotic Hydrilla verticillata and the Native Najas guadalupensis – Scott D. Jackson, Forrest E. Dierberg, Lisa Canty and Thomas A. DeBusk; DB Environmental, Inc., Rockledge, FL............................................................................................ (p. 51)

10:40am-11:00am Phosphorus Removal Performance of a Harvestable Pasture Grass Cultivated in a Treatment Wetland – Patrick Owens and Thomas A. DeBusk; DB Environmental, Inc., Rockledge, FL..... (p. 80)

11:00am-11:20am Effect of Integrated Nutrient Management on the Maintenance of Soil Fertility Under Flooded Rice Eco-System – Pintu Sur and D. K. Das; Department of Agricultural Chemistry & Soil Science, Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal, India ................................................................................ (p. 100)

11:20am-11:40am Reciprocating Constructed Wetlands: Influence of Organic Loading Rate, Reciprocation Cycle Time and Planting Regime – Leslie Behrends1, Laura Houke1, Earl Baily1 Pat Jansen1 and Don Brown2; 1Tennessee Valley Authority, Department of Air Land and Water Sciences, Muscle Shoals, Al USA; 2US EPA, Cincinnati, Ohio ...................................................................... (p. 5)

11:40am-12:00pm Important of Natural Wetlands for Polluted Water Treatment – Igor Prokofev and Ludmila Zhirina; Bryansk State Engineering-Technology Academy and Environmental NGO VIOLA, Bryansk, Russia ........................................................................................................... (p. 86)


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Wednesday, March 23, 2005 (continued)

SESSION B2: NUTRIENT TRANSFORMATION PATTERNS - LABORDE HALL Session Chair: Tiffany Troxler-Gann

10:20am-10:40am Direct Measurement of Denitrification Activity in a Gulf Coast Freshwater Marsh Receiving Diverted Mississippi River Water – Kewei Yu1, Ronald D. DeLaune1 and Pascal Boeckx2; 1Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA 70803, USA; 2Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry (ISOFYS), Ghent University, Gent, Belgium...................................................................................................... (p. 116)

10:40am-11:00am Nitrogen Removal of a Large River Swamp System -- The Atchafalaya River Basin – Y. Jun Xu; School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA, USA......................................................................... (p. 114)

11:00am-11:20am Nutrient Transformations During Floodplain Inundation – Durelle Scott, Judson Harvey and Gregory Noe; U.S. Geological Survey, Reston, VA, USA ...................................................................... (p. 77)

11:20am-11:40am Extracellular Enzyme Activity and Distribution in Benthic Cyanobacterial Mats: Comparison between Nutrient Enriched and Unimpacted Sites in Marshes of Northern Belize – D. Sirova1, J. Vrba1,2 and E. Rejmankova3; 1University of South Bohemia, Faculty of Biology, Department of Ecology, Ceske Budejovice, Czech Republic; 2Hydrobiological Institute AS CR, Ceske Budejovice, Czech Republic; 3University of California, Department of Environmental Science and Policy, Davis, CA, USA ........................................................................................ (p. 98)

11:40am-12:00pm Change in Nitrate Transfer in the Unsaturated Zone of the Soil according to the Duration of Flood Suppression in a Recently Reflooded Area (the Polder of Erstein East of France) – S. Defraeye and M. Trémolières; Centre d'Ecologie Végétale et d'Hydrologie CEVH, Strasbourg, France........................................... (p. 30)

12:00pm Symposium Concludes


xxv

Poster Session I Directory Monday, March 21, 2005; 5:00pm-7:00pm

Abstract page numbers are indicated at the end of listings [example: “…(p. 2)”]

Poster No. 1..........Benthic Nutrient Flux in a Louisiana Marsh Using the Flume Technique – J. Baker1

and R. Twilley2; 1University of Louisiana at Lafayette, Biology Department, Lafayette, LA, USA; 2Louisiana State University, Wetland Biogeochemistry Institute, Baton Rouge, LA, USA ............................................................................................................................................... (p. 3)

2..........Measurement of Benthic Nutrient Fluxes in a Louisiana Marsh Impacted by the Freshwater Diversion Restoration Project at Caernarvon, LA – Robert R. Twilley and Daniel C. Bond; Louisiana State University, Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Baton Rouge, LA, USA ............... (p. 9)

3..........Effects of Nutrient Enrichment on Benthic Nitrogen Fixation in Mangrove Microbial Communities of Bocas del Toro Province, Panama – Rachel Borgatti1,2, Judith M. O’Neil1, William C. Dennison1 and Ilka C. Feller2; 1University of Maryland Center for Environmental Science, Horn Point Laboratory, Cambridge, MD; 2Smithsonian Environmental Research Center, Edgewater, MD ....................................... (p. 10)

4..........Spatial and Temporal Dynamics of Radial Oxygen Loss from Single Attached Roots of some North American and Central European Wetland Plants – S. Bloßfeld1, J. Busch1, R. Lösch1 and I. A. Mendelssohn2; 1Heinrich-Heine-University Düsseldorf, Department of Geobotany, Düsseldorf, Germany; 2Louisiana State University, Wetland Biogeochemistry Institute, Baton Rouge, LA, USA .............................................................. (p. 14)

5..........Distribution of Surficial Sediments and Total Organic Carbon in Chantuto-Panzacola Coastal Lagoon, Chiapas, Mexico – L. G. Calva-Benítez and R. Torres-Alvarado; Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Hidrobiología, Mexico City, México.......................................................................................... (p. 15)

6..........Spatial and Temporal Variation of Porewater Variables in Mangrove Forests along the Shark River and Taylor Sloughs, South Florida – E. Castaneda1, R. R. Twilley1, V. H. Rivera-Monroy1, K. de Mutsert1 and C. Coronado-Molina2; 1Louisiana State University, Department of Oceanography and Coastal Sciences, Wetland Biogeochemistry Institute, Baton Rouge, LA, USA; 2South Florida Water Management District, West Palm Beach, Florida, USA................................................................................. (p. 16)

7..........Comparison of Soil Phosphorus, Iron and Sulfur Pools in the Everglades/ Florida Bay Ecosystem – Randy Chambers, Kristin Pederson and Mary Shockley; Keck Environmental Field Lab, College of William and Mary, Williamsburg, VA ............... (p. 17)


xxvi

Poster No. 8..........Molecular Characterization of Mangrove Vegetation and Sediment Cores from the

Shark River Estuary, Florida – Joshua B. Cloutier1, Rudolf Jaffe1,2 and Victor Rivera-Monroy3; 1Department of Chemistry and Biochemistry, Florida International University, Miami, FL; 2Southeast Environmental Research Center, Florida International University, Miami, FL; 3Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Science, Louisiana State University, Baton Rouge, LA ........................................ (p. 19)

9..........Phosphorus Removal in a Constructed Wetland Dominated by Submerged Aquatic Vegetation – S. Curtis1, J. White2 and M. Belmont2; 1University of Florida, Soil and Water Science Department, Gainesville, FL; 2 Louisiana State University, Wetlands Biogeochemistry Institute, Baton Rogue, LA .......................................................................... (p. 22)

10........Flux of Organic and Inorganic Nutrients in a Fringe Mangrove Forest in the Shark River Estuary, Florida, USA – Robert R. Twilley1, Kim de Mutsert1, Victor H. Rivera-Monroy1, Edward Castañeda1, Melissa Romigh2 and Stephen Davis2; 1Louisiana State University, Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Baton Rouge, USA; 2 Texas A&M University, College Station, Texas, USA ...................................................................................................................................................... (p. 28)

11........Metal Accumulation in Intertidal Litter through Decomposing Leaf Blades and Stems of Phragmites australis – G. Du Laing1, G. Van Ryckegem2, F. M. G. Tack1 and M. G. Verloo1; 1Ghent University, Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent, Belgium; 2Ghent University, Laboratory for Botany, Ghent, Belgium ............................................................................................................................................... (p. 35)

12........Metal Pore Water Concentrations as affected by Soil Redox Status and Moisture Regime – D. Vanthuyne1, G. Du Laing1, J. Wustenberghs1, B. Vandecasteele2, F. M. G. Tack1 and M G. Verloo1; 1Ghent University, Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent, Belgium; 2Institute for Forestry and Game Management, Geraardsbergen, Belgium............................................................................................................... (p. 36)

13........Phosphorus Storage by Historically Isolated Wetland Ecosystems within Grazing Pastures of Okeechobee Basin, Florida – E. J. Dunne, M. W. Clark and K. R. Reddy; Soil and Water Science Department, University of Florida/IFAS, Gainesville, FL ..... (p. 37)

14........An Assessment of Historical Vegetation Change and Organic Matter Preservation in Freshwater Wetlands of the Florida Everglades: A Biogeochemical, Multi Proxy Approach – Min Gao1, Colin Saunders2, Dan Childers2 and Rudolf Jaffé1; 1Florida International University, Department of Chemistry and Biochemistry, Miami, FL, USA; 2Florida International University, Department of Biology, Miami, FL, USA ................ (p. 41)

15........Fate of 15N-labeled Ammonium and Nitrate in a Poorly Drained Lolium perenne Field and Herbaceous Riparian Area in Western Oregon – J. H. Davis1, S .M. Griffith1, W. R. Horwath2, J. J. Steiner1 and D. D. Myrold3; 1U.S.D.A. Agricultural Research Service, Corvallis, OR; 2University of California, Davis, CA; 3Oregon State University, Corvallis, OR............................................................................................................... (p. 44)


xxvii

Poster No. 16........Geospatial Mapping of Soil Total Phosphorus in the Greater Everglades Ecosystem

– S. Grunwald1, R. Corstanje1, G. L. Bruland1, T. Z. Osborne1, R. G. Rivero1,2, S. Newman3 and K. R. Reddy1; 1 Soil and Water Science Department, University of Florida, Gainesville, FL, USA; 2 Department of Urban and Regional Planning, University of Florida, Gainesville, FL, USA; 3 South Florida Water Management District, West Palm Beach, FL, USA................................................................................................................................ (p. 45)

17........Interannual Variability of Two Mexican Tropical Coastal Wetlands – M. F. Gutiérrez, F. Varona-Cordero and G. N. Rivera,; Coastal Ecosystems Laboratory. Universidad Autónoma Metropolitana-Iztapalapa, México City, México ...................... (p. 47)

18........Denitrification Enzyme Activity in Constructed Wetlands and Riparian Zones – P. G. Hunt1, T. A. Matheny1, M. E. Poach1 and G. B. Reddy2; 1USDA-ARS Coastal Plain Soil, Water, and Plant Research Center, Florence, SC; 2North Carolina A&T State University, Greensboro, NC.......................................................................................................... (p. 48)

19........Comparative Assessment of Counter-Measures Efficacy Used in Meadow Cultivation for Transition Reduction of 137CS and 90SR in Grasses of Various Types of Meadows – Artur Katushynskiy; Khmelnytskyy Institute of Agroecology and Biotechnology, Khmelnytskyy, Ukraine ................................................................................... (p. 54)

20........Microbial Factors Affecting Transformation of CH4 and N2O in Rice Soils from Different Regions – I. Kravchenko1 and K.Yu 2; 1Winogradsky Institute of Microbiology RAS, Moscow, Russia; 2Wetland Biogeochemistry Institute, LSU, Baton Rouge, USA........................................................................................................................... (p. 57)

21........Pilot-scale Horizontal Subsurface Flow Treatment Wetlands for Model Calibration Purposes – Els Lesage1, D.P.L. Rousseau2, A. Story2, N. De Pauw2, P.A. Vanrolleghem3, F.M.G. Tack1 and M.G. Verloo1; 1Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent, Belgium; 2Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent, Belgium; 3BIOMATH, Ghent, Belgium.................................................... (p. 61)


xxviii


xxix

Poster Session II Directory Tuesady, March 22, 2005; 5:00pm-7:00pm

Abstract page numbers are indicated at the end of listings [example: “…(p. 2)”]

Poster No. 1..........Nutrient Cycling in a South Carolina Tidal Salt Marsh – Christel J. Lopez, Emily N.

Sekula, Lauren C. Kolowith, Liza M. Johnson and Timothy J. Callahan; Department of Geology and Environmental Geosciences, College of Charleston, Charleston, SC ..... (p. 63)

2..........Seasonal Dynamics Assessment of Greenhouse Gases Emission in Peat Soils of Flood-Lands of River Stokhid – Vitaliy Luchka; Khmelnytskyy Institute of Agroecology and Biotechnology, Khmelnytskyy, Ukraine ................................................. (p. 64)

3..........Isotopic and Nutrient Relations of Plants from Coastal Wetlands Regulated by Salinity and Flooding Gradients: The Guanoco Stream in Venezuelas Northeastern Coastal Plain – E. Medina1,2, A.M. Francisco M.1 and Quilice A.3; 1 Centro de Ecología, IVIC, Caracas, Venezuela; 2 IITF, USDA Forest Service, San Juan, Puerto Rico; 3

Departamento de Ecología y Ambiente, PDVSA-INTEVEP, Los Teques, Venezuela ........................................................................................................................................... (p. 68)

4..........Significance of Coupling of Nitrification and Nitrate Reduction on Water Quality of a Coastal Lake Receiving Nitrate in Diverted Mississippi River Water – Shenyu Miao2, R. D. DeLaune1 and Aroon Jugsujinda1; 1Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA; 2School of Biological and Chemical Engineering, Guangzhou University, Guangzhou .................................................................. (p. 70)

5..........Carbon and Nitrogen Mineralization of Cowdung and Poultry Manure Amended Soil under Anaerobic Condition – Umme A. Naher; Soil Science Division, Bangladesh Rice Research Institute, Gazipur, Bangladesh ......................................................................... (p. 72)

6..........Nitrogen Cycling and Ecosystem Exchanges in a Virginia Tidal Freshwater Marsh – Scott C. Neubauer1,2, Iris C. Anderson2 and Betty B. Neikirk2; 1University of South Carolina, Baruch Marine Field Laboratory, Georgetown, SC, USA; 2The College of William and Mary, School of Marine Science, Virginia Institute of Marine Science, Gloucester Point, VA, USA .......................................................................................................... (p. 74)

7..........The Role of Particulate Phosphorus in Everglades Wetlands – Gregory Noe1, Judson Harvey1 and James Saiers2; 1U.S. Geological Survey, Reston, VA; 2Yale University, New Haven, CT........................................................................................................................................... (p. 78)

8..........Horizontal and Depth Distribution of Soil C, N and P in a Seasonal Wetland, China – Genxing Pan1, Chuande Chi1, Lianqing Li1, Xinwang Xu2 and Xinmin Wu2; 1Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing, China; 2Chizhou Teachers College, Anhui Province, China .............................. (p. 81)


xxx

Poster No. 9..........Decomposition of Mangrove Roots in Different Hydrogeomorphic Mangrove Sites

in South Florida – N. Poret1, R. R. Twilley2 and V. Rivera2; 1University of Louisiana , Lafayette, LA, USA; 2Louisiana State University, Wetland Biogeochemistry Institute, Baton Rouge, LA, USA .................................................................................................................. (p. 84)

10........Modeling Phosphorus Dynamics in the Shark River and Taylor Sloughs, Everglades National Park – Colin Saunders and Daniel L. Childers; Southeast Environmental Research Center, Florida International University, Miami, FL .......................................... (p. 94)

11........Sediment Accretion and Long Term Sequestration of Phosphorus and Carbon in Periphyton-Dominated Stormwater Treatment Areas – L. J. Scinto1, J. Haberer1 and S. Long2; 1Florida International University, Southeast Environmental Research Center, Miami, FL, USA; 2Professional Service Industries, Inc., Tampa, FL, USA ................... (p. 95)

12........Enzymatic Controls on Primary Production and CNP Stoichiometry in Wetland Metaphyton – J. Thad Scott and Robert D. Doyle; Center for Reservoir and Aquatic Systems Research, Department of Biology, Baylor University, Waco, TX, USA........ (p. 96)

13........Can the Wetlands Save the Lake? The Role of a Constructed Wetland in Protecting the Water Quality of Lake Waco – R. Doyle, T. Scott and T. Conry; Center for Reservoir and Aquatic Systems Research, Baylor University & City of Waco, Waco, TX. USA ...................................................................................................................................................... (p. 32)

14........A Pilot Study: Greenhouse Gas Emissions from Soils in Southeastern U.S. Forests – Emily N. Sekula1, Carl C. Trettin2 and Timothy J. Callahan3; 1Department of Geology and Environmental Geosciences, College of Charleston, Charleston, SC; 2USDA-Forest Service, Southern Research Station, Center for Forested Wetlands Research, Charleston, SC; 3Department of Geology and Environmental Geosciences, College of Charleston, Charleston, SC................................................................................................................................... (p. 97)

15........Use of Porewater Calcium: Magnesium Ratios to Track Source Waters to, and Distinguish among Plant Communities in Coastal Louisiana Peat Marshes – C. M. Swarzenski1 and T.W. Doyle2; 1United States Geological Survey, Baton Rouge, Louisiana, USA; 2United States Geological Survey, Lafayette, Louisiana, USA ....... (p. 102)

16........Mercury Levels in Fish in Lake Pontchartrain – M. Tan1, A. Hou1, M O'Connell2 and R. DeLaune1; 1Louisiana State University, Baton Rouge, LA, USA; 2University of New Orleans, New Orleans, LA, USA............................................................................................... (p. 103)

17........Wintertime Stable Isotopic and Geochemical Profiles from Pore water Peepers at the Margin of an Acidic Wetland, Bear Meadows, Centre County, PA – Burt Thomas and Michael Arthur; The Pennsylvania State University, Department of Geosciences, State College, PA.................................................................................................. (p. 104)

18........Nutrient Cycling in Indian River Lagoon Marsh Impoundments: Using Ecological Network Analysis to Determine Effects of Management – Cassondra R. Thomas; NASA, Kennedy Space Center, FL........................................................................................... (p. 105)


xxxi

Poster No. 19........Organic Matter Mineralization: Terminal Anaerobic Steps in Tropical Wetlands –

R. Torres-Alvarado1, F. J. Fernández2, V. H. Rivera-Monroy3, L. G. Calva-Benítez1 and F. Ramírez-Vives2; 1 Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Hidrobiología, Mexico City, Mexico; 2 Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biotecnología, Mexico City, Mexico; 3 Louisiana State University, Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Baton Rouge, Louisiana, USA ................................................................................................... (p. 106)

20........The Practice and the Conception for Treating the Polluted Water by Using the Natural Wetlands – Wu Xiangde and Aolei Qiu; L’Association du Marécage au Cameroun.......................................................................................................................................... (p. 113)

21........Reconstruction of Historical Mangroves in South Florida Coastal Areas through a Biomarker Approach – Yunping Xu and R. Jaffé; Environmental Geochemistry Laboratory, Southeast Environmental Research Center (SERC) and Department of Chemistry & Biochemistry, Florida International University, Miami, FL USA ......... (p. 115)

22........Reestablishing the Vegetation and Environmental Changes in Beijing Area from 16000-7000 Years B.P. – Jiahua Zhang and Fengmei Yao; Chinese Academy of Meteorological Sciences, Beijing, China ................................................................................ (p. 117)


xxxii


1

Symposium Abstracts

Listed alphabetically by presenting author.

Presenting authors appear in bold.


2


3

Benthic Nutrient Flux in a Louisiana Marsh Using the Flume Technique J. Baker1 and R. Twilley2

1University of Louisiana at Lafayette, Biology Department, Lafayette, LA, USA 2Louisiana State University, Wetland Biogeochemistry Institute, Baton Rouge, LA, USA

It is believed that diverting Mississippi River water back into the adjacent wetlands will help reduce high concentrations of nutrients prior to the water reaching Gulf of Mexico and therefore help alleviate the Hypoxic zone located in the Northern region of the Gulf of Mexico. The diversion is also intended to stimulate wetland growth through the addition of nutrient rich water. The goal of this study was to examine fluxes of nutrients during two pulse events in early 2004. A series of two adjacent 4 m x 100 m flow through flumes were constructed at two sites in the upper portions of the Breton Sound Estuary in Southeastern Louisiana. The Big Mar site was located approximately 25 km south of the Caernarvon river diversion structure; The Camp site was located 7.5 km SW of the first. At each site, one flume was used as a reference to natural environmental conditions, while the treatment flume was used to manipulate flow conditions. At each site the water depth remained near 0.25 m throughout both pulses. Within a pulse the adjacent flumes experienced significantly different flows. For the March Pulse, at the Big Mar site, mean flows were 2.35 cm/s in the reference flume and 1.05 cm/s in the treatment flume. The Camp site experienced mean flows of 0.22 cm/s in the reference flume and 0.14 cm/s in the treatment flume during the same March pulse. A temperature gradient was evident as distance from the diversion increased. The average temperature during the March pulse increased from 14.97 °C to 20.78 °C between the two sites. At each flume, NH4

+, NO3-, NO2

-, PO4-3, Si, total

nitrogen (TN), total phosphorus (TP), dissolved organic nitrogen (DON) and dissolved organic phosphorous (DOP) were measured. When moving from the Big Mar site to the Camp site, each parameter showed a significant decrease in the upstream concentrations. NO3

- and PO4-3 are two

of the most frequently examined water quality parameters. During the March pulse mean upstream NO3

- concentrations for the Big Mar reference flume were 106.07 µM. At the Camp site this concentration was 0.20 µM. At the same time, the Big Mar reference flume’s upstream concentration of PO4

-3 was 0.70 µM. The Camp site reference flume had a concentration of 0.30 µM. During the March pulse at the Big Mar site, the reference flume experienced a significantly more negative NO3

- flux compared to a slightly positive flux from the treatment flume, -21.49 mg m-2 hr-1 and 1.05 mg m-2 hr-1 respectively. There was no significant difference between flumes at the Camp site. The reference and treatment flumes experienced flux rates equal to 0.00 mg m-2 hr-1. This is more than likely due to the very low initial concentration experienced at this site. At the Big Mar site, there was no significant difference between flumes for PO4

-3; both sides had a flux rate of -0.33 mg m-2 hr-1. The same inter-flume statistical equality was evident at the Camp site. Here the flux rates for PO4

-3 were -0.01 mg m-2 hr-1 and 0.01 mg m-2 hr-1 for the reference and treatment flumes respectively. Contact Information: J. Baker, University of Louisiana at Lafayette, Biology Department, Lafayette, LA 70501, Phone: 337-482-5248, Email: [email protected]


4

ReCiprocating Constructed Wetlands for Treating High Strength Anaerobic Lagoon Wastewater Leslie Behrends, E. Bailey, W. Ellison, L. Houke, P. Jansen, C. Shea, S. Smith and T. Yost

Tennessee Valley Authority, Department of Air Land and Water Sciences, Muscle Shoals, AL, USA Innovative zero-discharge wastewater treatment systems are needed for treating nutrients, noxious odors, dissolved organic matter, and pathogens from high strength agricultural and processing wastewater. A novel reciprocating subsurface-flow constructed wetland (ReCip®), consisting of four cells totaling 3570 m2 (1.5 m deep), has been operated to treat high strength anaerobic lagoon wastewater from a commercial-scale confined swine feeding operation. The system, located near Aliceville, Alabama, has been in operation for four years. Hydraulic loading rates (HLR’s), from the anaerobic lagoon to the wetlands treatment system averaged 107 and 208 m3/day for years I and II respectively. Results to date indicate that the system’s treatment efficacy is sustainable, with the exception of phosphorus removal. Doubling the flow rate did not significantly reduce treatment efficacy with respect to monitored parameters. Average influent and effluent concentrations (ppm), of monitored parameters and their respective percentage removal rates were: CBOD5 ( 521, 117, 78%); COD ( 1388, 393, 72%); NH4-N (371, 51, 86%); and PO4-P (52, 43, 17%). Electrical demand to operate reciprocating pumps, influent pumps and irrigation pumps averaged 203 kWh/day and 234.1 for the two wastewater loading rates respectively. The system was very effective in removing odors from the lagoon wastewater. Fecal coliform bacteria removal rates ranged from 2-3 Log reduction. In conclusion, the reciprocating wetland system was efficient with respect to removal of organic compounds, nitrogen, odor and fecal coliform bacteria. Further research will be required to enhance phosphorus removal. Contact Information: Leslie Behrends, Tennessee Valley Authority, Air, land and Water Sciences, CEB 1-C, Muscle Shoals, AL 35662, Phone: 256 386 3488, FAX: 256 386 2191, Email: [email protected]


5

Reciprocating Constructed Wetlands: Influence of Organic Loading Rate, Reciprocation Cycle Time and Planting Regime Leslie Behrends1, Laura Houke1, Earl Baily1 Pat Jansen1 and Don Brown2

1Tennessee Valley Authority, Department of Air Land and Water Sciences, Muscle Shoals, Al USA 2US EPA, Cincinnati, Ohio

A microcosm treatability study of eight days duration, was conducted in an environmentally controlled greenhouse located at TVA’s Constructed Wetlands Research Facility in Muscle Shoals, Alabama, USA. The study was designed to simultaneously evaluate the influence of several parameters on treatment of COD, total ammonia-nitrogen(TAN), nitrate-nitrogen (NO3-N) and phosphorus. The parameters evaluated included CBOD5 loading rates (50, 100, 200, and 400 mg/L); reciprocation cycle times (0, 6 and 12 cycles/day); and the presence or absence of reed canary grass, Phalaris arundinacea, a plant that has an anoxic rootzone to enhance denitrification. Each of thirty microcosms (70L), were divided into two equal compartment with a permanently-fixed vertical glass partition. Each of the two compartments was plumbed to accommodate recurrent draining and filling via independent air-lift devices. Both sides of each microcosm were backfilled with 2.5 cm of limestone rock (2.5 -4.0 cm), which was overlaid with 25 cm of river gravel (0.5 to 1.0 cm). Synthetic wastewater solutions consisting of milk replacement starter and additional nutrients (total ammonia nitrogen = 100 ppm, total P = 50 mg/L), were batch loaded into replicates or respective treatments at the start of the study. Reciprocation significantly improved wastewater treatment with respect to COD, and TAN removal rates. Changes in COD were rapid, with reductions (46-95%), occurring within the first 24 hours. However, within a given organic loading rate and as a function of reciprocation regime (6 vs 12/day), differences in percentage removal rates were small, averaging only 2 to 3 percent. Thus, with respect to COD removal, there was no clear advantage to increasing the reciprocation regime from 6 to12 times/day. Results indicate that COD removal was influenced by an interaction between reciprocation regime (0 vs 6 vs 12 cycles/day), and planting regime (plants, Y vs. N). Total ammonia-nitrogen removal was rapid and complete (>99%), in reciprocating treatments, but significantly slower and less complete in the non-reciprocating treatments. Selected high COD treatments with plants had marginally better removal of total ammonia (5-10%), than non-planted controls. Nitrate dynamics among treatments was dramatically influenced by reciprocation and the presence of plants. High rate COD treatments with reciprocation and plants had elevated nitrate levels (15-25 mg/L), while all other treatments had insignificant nitrate accumulation. Rapid accumulation of nitrate in aerated systems is consistent with carbon being limited for denitrification. Results further indicate that canary grass was a major source of carbon for denitrification. Removal of ortho-P was extremely rapid and near complete within the eight day study. Removal rates ranged from 92 to 100 % Field studies have revealed that P removal in new wetland systems is due primarily to adsorption, which provides a short-term sink. Contact Information: L. Behrends, Tennessee Valley Authority, Department of Air, Land and Water Sciences, Muscle Shoals, AL 35662 USA; Phone: 256 386 3488, Fax: 256 386 2191, Email: [email protected]


6

Screening Aquatic Plants for Nitrate Removal Potential Leslie L Behrends, E. Bailey, L Houck, P. Jansen, P. Pier and T. Yost

Department of Air Land and Water Sciences, Tennessee Valley Authority, Muscle Shoals, AL USA Engineered constructed wetlands are being developed to remove nutrients from animal wastewater treatment systems. In these systems nitrate removal can be accomplished by plant uptake, microbial denitrification or both. Nitrate can be biologically denitrified to nitrogen gas, but the denitrifying bacteria require low redox conditions and organic carbon to complete the process. Many plant species produce sugar-like compounds which are subsequently translocated to the root zone and leaked into the rhizosphere. This provides an available carbon source for enhancing denitrification. Studies were conducted at TVA’s Constructed Wetland Research Center (Muscle Shoals, AL), to identify aquatic plant species that have the capacity to enhance removal of nitrate via plant uptake and denitrification. Replicated pot studies (3 replicates per treatment), were established in an environmentally controlled greenhouse to monitor the impact of eight plant species, 4 rearing environments (open water vs gravel substrate; with or without duckweeds), and plant by environment interactions with respect to redox potential and nitrate removal dynamics. Nitrate removal rates were normalized to mg N03 removed per kg of plant (dry matter basis) / per unit time. In addition, N-15 labeled nitrate was used in one of the sub-studies to evaluate the relative removal of nitrate via plant uptake and denitrification. Redox values were found to differ significantly among plant species and over sampling dates (P<0.05). Canary grass in gravel substrates had the lowest redox potential, and irrespective of plant species, redox potential trended lower over time. Potassium nitrate (50 mg/L as N) was batch loaded into the microcosms on several occasions and monitored for eight day periods. Canary grass, cattail, and common reed in gravel substrates were all able to remove nitrate to levels less than 10 mg/L) within 4 days. Yellow iris and Parrots feather were able to reduce nitrate to comparable levels after eight days. Dry matter plant production (g dry matter/pot) was significantly higher in gravel vs water based systems (P<0.05). In gravel based systems, dry matter plant production ranged from less than 50 g/pot (dwarf papyrus) to over 135 g/pot (common reed). In water based systems, dry matter plant production ranged from less than 10 g/pot (yellow iris) to 93 g/pot (cattail Contact Information: L. L. Behrends, Tennessee Valley Authority, CEB 1-C, Muscle Shoals, Alabama USA 35662, Phone: 256-386-3488, Fax: 256-386-2191, Email: [email protected]


7

Presence of Pharmaceuticals in a Large Treatment Wetland in Florida, USA Marco A. Belmont1, John R. White1 and Chris D. Metcalfe2

1 Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA, USA 2 Water Quality Centre, Trent University, Peterborough, Ontario, Canada

Traditionally, municipal wastewater treatment plants have been designed to remove pathogens, suspended solids, organic material, nitrogen and phosphates from domestic sewage. Recently, concern has risen about the possibility that domestic sewage may be a source of organic contaminants that could also impact the aquatic environment. There are a variety of compounds that have been detected in domestic sewage that have biological activity. These include endocrine disruptants, antibiotics, personal care products, antibacterial agents, and several classes of prescription and non-prescription drugs. These contaminants may produce biological responses in fish and other aquatic organisms. In addition, there is concern that antibiotics released from domestic wastewater treatment plants may lead to antibiotic resistance of microorganisms in the environment. Treatment wetlands have been used effectively as a low-cost alternative for wastewater treatment. There are many studies on the use of these natural treatment systems for treatment of a variety of waste waters, including domestic sewage. However, there are no studies about the removal of the above mentioned organic contaminants by natural or constructed wetlands. This paper reports for the first time the removal of pharmaceuticals by a large treatment wetland. The antibiotic trimethoprim, the vasodilator pentoxifylline, the antineoplastic cyclophosphamide, the antiepilectic and psychiatric drug carbamazepine, the analgesic fenoprofen, the lipid-regulator gemfibrozil, and ibuprofen were found in the influent of the treatment wetland (effluent of advanced secondary wastewater treatment). Most of these compounds were reduced to below detection limits by the treatment wetland. However, cyclophosphamide, carbamazepine and fenoprofen were very persistent and reached the receiving water bodies despite of the fact that the municipal wastewater received advance secondary treatment and had a >30 days residence time in the treatment wetland. The xenobiotics caffeine and cotinine (a metabolite of nicotine) were found in the influent of the treatment wetland. Cotinine were also found in the effluent. This persistent compound can be good tracers of water pollution with human wastes. Contact Information: Marco A. Belmont, Wetland Biogeochemistry Institut,. Louisiana State University, Baton Rouge, LA, USA 70803, Phone: (225)328-4888, Fax: (225)578-6423, Email: [email protected]


8

Strategic Restoration of Wetlands on Private Lands: Regional Approaches in the Lake Okeechobee Watershed Patrick J. Bohlen1, Stanley Gathumbi1, Kathleen McKee2, Mark Clark2 and Sabine Grunwald2

1Archbold Biological Station, MacArthur Agro-Ecology Research Center, Lake Placid, FL 2University of Florida, Soil and Water Science, Gainesville, FL

Restoring wetland functions and values at broad regional scales cannot be achieved without creating incentives for restoring wetlands on private lands. The importance of private lands for wetland restoration has provided the impetus for federal conservation programs, such as the USDA Wetland Restoration Program (WRP), specifically designed to encourage wetland restoration on agricultural land. Many other programs are available to land owners interested in receiving payments, establishing easements or acquiring cost sharing to restore wetland functions on their land. The Lake Okeechobee watershed in South Florida is an exemplary case of a region in which wetland restoration is being pursued through cooperative efforts among state agencies, university faculty, conservation groups and private research organizations. The main strategic focus in this watershed is reduction of P loads into Lake Okeechobee, with the presumption that restoring wetlands will increase P storage or reduce P runoff in the watershed. Beef cattle ranching is the main land use in the region; so, there is a need for better understanding of the biogeochemistry of wetlands on ranches, their response to cattle ranching practices, and their potential to act as nutrient sinks or sources of nutrients in the watershed. Several research efforts are underway to assess the multiple functions and values of isolated wetlands and other wetland systems on ranchlands in the Lake Okeechobee basin. Analysis of nutrient storage in sediments and vegetation in more intensively managed improved cattle pastures versus less intensively managed semi-native pastures showed significant nutrient enrichment, especially of P, in wetland soils and vegetation in improved pasture wetlands. Surface water P concentrations were an order of magnitude higher in improved pasture wetlands than in semi-native pasture wetlands. Differences in the N:P ratios of wetland vegetation suggested that nutrient enrichment in the improved pastures may have shifted wetlands from a P-limited to an N-limited state. Increased P concentration in improved pasture wetlands is attributed to use of P fertilizer, which has declined on most ranches over the past two decades. Analysis of the distribution of isolated wetlands in the watershed showed that these systems accounted for approximately 13-15% of the landscape area. Hydrologic restoration of these wetlands has the potential to increase organic matter and thus P storage in wetland sediments. However, it remains to be determined whether nutrient enrichment of these systems due to past and current ranch management practices will decrease their potential to act as nutrient sinks in the long-term. Other regional efforts, such as large scale wetland restoration and improved water management on private lands, have the potential to enhance wetland functions on a wider scale, improving water quality and increasing water storage in the watershed, both of which are critical components of the Comprehensive Everglades Restoration Program (CERP). Contact Information: Patrick J. Bohlen, Archbold Biological Station, MacArthur Agro-ecology Research Center, 300 Buck Island Ranch Rd., Lake Placid, FL 33852, Phone: (863) 699-0242, Fax: (863) 699-2217, Email: [email protected]


9

Measurement of Benthic Nutrient Fluxes in a Louisiana Marsh Impacted by the Freshwater Diversion Restoration Project at Caernarvon, LA Robert R. Twilley and Daniel C. Bond

Louisiana State University, Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Baton Rouge, LA, USA

Freshwater diversions are an important tool in the restoration of wetlands associated with the Mississippi deltaic plain in coastal Louisiana. Extensive agricultural activity in the Mississippi River Basin has led to significant increases in nitrate-nitrogen concentrations in the river, particularly since the 1950’s, when nitrogen fertilizer came into increasing use. There is some concern that river diversions will lead to eutrophication of inland waters and estuaries, causing a decline in water quality. It is therefore important to understand the capacity of the wetlands associated with these diversions to remove nitrogen from the inundating water column. In this study we used a core incubation technique to evaluate spatial and temporal patterns of nutrient dynamics in the upper Breton Sound Estuary. We evaluated fluxes of NH4, NO3, NO2, PO4, DON, and DOP along gradients of increasing salinity and decreasing soil fertility moving downstream from the diversion structure. Porewater nutrient concentrations, soil bulk density, and soil C:N ratios were measured at each location. Experiments were conducted during two high-flow diversion pulse events in spring 2004, and during a low-flow diversion event in July ’04. Water used for the core incubations was collected near the diversion outfall structure, and contained high concentrations of nitrate (60-120μM). Direct measurement of rates of fluxes using this batch core incubation method may improve our understanding of the nitrogen processing capacity of these wetlands. Contact Information: Daniel C. Bond, Louisiana State University, Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Energy Coast and Environment Building 3207, Baton Rouge, LA 70803, USA, Phone: (225) 578-2771, E-mail: [email protected]


10

Effects of Nutrient Enrichment on Benthic Nitrogen Fixation in Mangrove Microbial Communities of Bocas del Toro Province, Panama Rachel Borgatti1,2, Judith M. O’Neil1, William C. Dennison1 and Ilka C. Feller2

1University of Maryland Center for Environmental Science, Horn Point Laboratory, Cambridge, MD 2Smithsonian Environmental Research Center, Edgewater, MD

Mangrove forests are vital for the maintenance of productive fisheries and protecting coastlines from erosion across the world’s tropical and subtropical regions. Mangroves are considered a sink for nutrients and have been used to treat aquaculture and sewage effluent. Increased runoff may overwhelm the mangrove ecosystem’s capacity to store nutrients and protect adjacent marine ecosystems (such as sea grass and coral reefs). Surprisingly little is known about the microbial community responsible for processing much of the nutrient inputs into the system. The focus of this study is the mangrove benthic microbial community and effects of long-term nutrient enrichment on nitrogen fixation. Stands of red mangrove (Rhizophora mangle L.) in the Caribbean have a distinct tree height gradient across the intertidal zone. Trees fringing the ocean are taller (~4 m tall) and give way to interior stands of shorter trees (< 1 m tall). Through a long-term fertilization experiment with additions of nitrogen (N) and phosphorus (P) in Almirante Bay, Bocas del Toro Province, Panama, this zonation has been shown to be primarily related to nutrient limitation. This long-term fertilization experiment was used to test the effects of in-situ nutrient additions and mangrove zonation on N2-fixation and photosynthesis of the benthic microbial community. The peat underlying the R. mangle trees fringing the water and the interior dwarf trees was sampled within 6 inches of the site of fertilization. Laboratory experiments quantified N2-fixation, pigment content, and photosynthetic activity of the benthic microbial community. The acetylene reduction assay was used to measure nitrogenase activity, the enzyme responsible for N2-fixation. Chlorophyll content of the autotrophic community was determined using standard extraction and fluorometry techniques. A photosynthesis yield analyzer (MINI-PAM) was used to measure chlorophyll fluorescence yield. Our findings indicate that N2-fixation rates were highest in the interior phosphorous fertilized trees. Photosynthetic activity varied among sites but, among the interior trees, was greatest in the phosphorous fertilized trees. Chlorophyll c was greatest in the fringing trees while chlorophyll a and b varied among sites. Thus we conclude that both zone and nutrient enrichment have a significant effect on the mangrove benthic community and N2-fixation. Contact Information: Rachel Borgatti, University of Maryland Center for Environmental Science, Horn Point Laboratory, 2020 Horn Point Road, P.O Box 775, Cambridge, MD 21613, Phone: 443.482.2244, Email: [email protected]


11

Effect of Macrophyte Diversity and Community Composition on Carbon and Nitrogen Cycles: An Experimental Study in Mesocosm Virginie Bouchard1, Serita Frey2, Janice Gilbert1 and Sharon Reed1

1School of Natural Resources, Ohio State University 2Department of Natural Resources, University of New Hampshire

We investigated the effect of plant functional group diversity on plant- and microbial-mediated functions related to N and C cycle, particularly denitrification and methanogenesis, in two mesocosm experiments simulating emergent freshwater wetlands. Five plant functional groups identified as clonal dominants, reeds, tussocks, facultative annuals, and obligate annuals were grown individually or in combinations of 2 to 5 functional groups. Denitrification, measured both under field conditions and in the lab as denitrifying enzyme activity, was not significantly different among our plant diversity treatments. When species of clonal dominants were included in the community, they out-competed the other species and decreased the overall effective functional diversity. Total CH4 flux, on the other hand, was significantly lower when 3-4 compared to 1-2 functional groups were grown together. Lower CH4 flux were observed with higher root biomass, suggesting that CH4 oxidation might have been the controlling factor decreasing CH4 emission. When species of clonal dominants were included in the community, they out-competed the other species and decreased the overall effective functional diversity. With the exclusion of the clonal dominant, methane accumulation in the sediment and methane fluxes to the atmopshere were significantly reduced in the most diverse treatment, and this inverse relationship with diversity was due to niche complementarity. Our results suggest that methane cycling may be more sensitive to changes in the plant community than is denitrification, and that a reduction in wetland plant diversity may lead to an increase in CH4 emissions to the atmosphere. Contact Information: Virginie Bouchard, School of Natural Resources, Ohio State University, 2021 Coffey Road, Columbus Ohio 43202, USA


12

Forested Wetland Dynamics Receiving Treated Municipal Wastewater: Nutrient Interactions and Forest Productivity Christopher G. Brantley and John W. Day, Jr.

Department of Oceanography and Coastal Sciences, School of the Coast and Environment, Louisiana State University, Baton Rouge, LA

This study provides information on freshwater ecosystem responses to secondarily treated wastewater effluent at Mandeville, Louisiana. Measurements of hydrologic input, nutrients, and aboveground net primary productivity were taken from September 1998 through March 2002. Accretion measurements were made in October 2000 and October 2004. With the exception of downstream effects of the sewage outfall, hydrologic input in the area is precipitation-driven. Nutrient levels were generally low in most areas except the outfall area. Downstream of the outfall, rapid nutrient uptake was observed, aboveground primary production was elevated significantly (P<0.001), and accretion measurements were significantly higher than reference plots (P<0.001), more than double the rate of relative sea level rise in the area. Removal efficiencies of N and P reached approximately 75% and 95%, respectively. The relatively constant flow of secondarily treated wastewater, besides providing a continuous source of water and nutrients, buffered the downstream area from salinity intrusion during a region-wide drought. This research has regional implications as the two global change models, (i.e., the Hadley and Canadian climate scenarios) predict increasing temperatures for the southeastern United States. Reductions in soil moisture are predicted in both scenarios and the Canadian model predicts reduced average precipitation. Re-direction of nutrient-enhanced effluents from open water bodies to wetland ecosystems has the potential to maintain plant productivity, sequester carbon, and maintain coastal wetland elevations in response to sea-level rise. Contact Information: Christopher G. Brantley, Department of Oceanography and Coastal Sciences, School of the Coast and Environment, Louisiana State University, Baton Rouge, LA 70803, Phone: 504-862-2224, Email: [email protected]


13

Geostatistical Analyses of Soils Data from Water Conservation Area 3, South Florida Gregory L. Bruland1, Sabine Grunwald1, Todd Z. Osborne1, K. Ramesh Reddy1 and Sue Newman2

1University of Florida/IFAS, Soil and Water Science Department, Gainesville, FL 2South Florida Water Management District, West Palm Beach, FL

The Florida Everglades represent one of the largest and most distinct wetlands in North America. This vast freshwater marsh is a subtropical peat-based ecosystem that was historically oligotrophic and phosphorus limited. Wetland conversion, hydrologic modifications, landscape fragmentation, and nutrient-rich runoff have significantly impacted the ecology of this region. Three Water Conservation Areas (WCAs) located to the south of the Everglades Agricultural Area (EAA) and to the north of the Everglades National Park (ENP) are currently used for water storage, flood control, and recreation. While WCA-3 is the largest (232,600 ha), it has been studied much less than WCA-1 or WCA-2. Soil is critical to the functioning of this ecosystem, and its assessment can provide feedback on both the ecosystem status and the effects of management. Thus, the objective of this study was to quantify and compare spatial distributions of soil properties in WCA-3. We used a stratified-random sampling design to collect over 300 soil samples from the floc, 0-10 cm, and 10-20 cm soil depths in WCA-3 in 2003 and 2004. These soil samples were analyzed for soil properties such as bulk density (BD), total phosphorus (TP), inorganic phosphorus (TPi), total nitrogen (TN), total carbon (TC), total calcium (TCa), and total magnesium (TMg). As WCA-3 is divided by two interior levees into WCA-3A to the north and WCA-3B to the south, we stratified our data accordingly. Furthermore, we divided WCA-3A into two zones, WCA-3AN (the area to the North of Interstate 75), and WCA-3AS (the area South of I-75). Geostatistical analyses indicated that spatial distributions were variable for different soil properties and among the three soil layers. was fairly consistent across the three zones of WCA-3, with the exception of the western part of 3AN. In this area BD values were considerably elevated with highest values of 0.72 g cm-3 (0-10 cm). Total P was quite variable across the 3 zones, with the highest values located in 3AN (720 mg kg-1, 0-10 cm). Total P levels were also elevated in each zone in areas adjacent to the Miami Canal. Total carbon showed a similar spatial distribution to BD. Maps of TCa and TMg shared some similarities with those of TP, but also exhibited distinctive patterns of variability. Mapping BD, TP, TCa, and TMg revealed that these properties tended to be highest and most variable in 3AN and 3B, especially in areas adjacent to canals. Unlike 3AN and 3B, 3AS appears to be least impacted by elevated phosphorus and cations. These results provide valuable insights into ecosystem dynamics in WCA-3 and will be useful in guiding future management and restoration efforts. Contact Information: Greg Bruland, University of Florida/IFAS, Soil and Water Science Department, 2169 McCarty Hall, PO Box 110290, Gainesville, FL 32611-0290, Phone: 352-392-1951 ext 210, Fax: 352-392-3902, Email: [email protected]


14

Spatial and Temporal Dynamics of Radial Oxygen Loss from Single Attached Roots of some North American and Central European Wetland Plants S. Bloßfeld1, J. Busch1, R. Lösch1 and I. A. Mendelssohn2

1Heinrich-Heine-University Düsseldorf, Department of Geobotany, Düsseldorf, Germany 2Louisiana State University, Wetland Biogeochemistry Institute, Baton Rouge, LA, USA

Up to now, the dynamic of the oxygen release from single attached roots of wetland plants is not well understood. Using oxygen micro-optodes, a non O2-consuming and flow-independent technique, we are capable to quantify oxygen release from individual roots with high spatial and temporal resolution both, in agar and waterlogged soil.

Temporal analysis showed, that we could distinguish between two different types of release rates: (1) a high release rate in situations with a strong oxygen-concentration gradient between root and rhizosphere, and (2) a low release rate in situations with a small oxygen-concentration gradient between root and rhizosphere. Spatial analysis of the oxidized zone of single attached roots (halo) for the different helophytes showed large inter- and intraspecific differences in O2 concentrations (0.8 - 3.45 mg O2 l-1) and O2 distribution within the halo.

The more natural approach of measurements allows a more detailed look at the spatial and temporal patchiness of oxygen distribution in the rooting zone of wetland soils. Presence or absence of oxygen, however, is an important influencing factor for biogeochemical processes in wetland soils and therefore influencing exchange processes between wetlands and the atmosphere, processes that influence and are influenced by global environmental changes.

Contact Information: J.Busch, Heinrich-Heine-University Düsseldorf, Department of Geobotany 40225 Düsseldorf, Germany, Phone: +49-211-81-14511, Fax: +49-211-81-13335, Email: [email protected]


15

Distribution of Surficial Sediments and Total Organic Carbon in Chantuto-Panzacola Coastal Lagoon, Chiapas, Mexico L. G. Calva-Benítez and R. Torres-Alvarado

Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Hidrobiología, Mexico City, México The surficial sediment distribution and total organic carbon (TOC) from Chantuto-Panzacola coastal lagoon, Chiapas State was evaluated. The site forming the largest area of mangrove forest in the North American Pacific, supports a large variety of wildlife that is threatened, endemic, rare, or in danger of extinction and is a site Ramsar no. 815. This study comprises sixteen sampling times between February (1997) up to July (2003) during the dry and wet seasons, including an atypical torrential storm (1998) and dredging operations since 2001; a total of ninety four samples were analyzed. Surface sediments were taken from 10 sites through lagoon system by means of a small stainless steel van Veen grab sampler (6 L). Total organic carbon determination was based on method of Gaudette et al. (1974) and sediment composition (sand, silt and clay content) was measured by standard wet sieving and pipette analysis (Folk, 1974). The mean percentages of TOC were to 2.58% until 4.96%, with the less value by stations with 0.16% reported on April (2002) until 12.88% during May (2003), but without differences. There was differences between dry and wet seasons (dry 3.28% and wet 4.49%). The content of TOC in the sediments were higher in the months associated to the wet season, showing that the contributions of the TOC to the system come from autochthonous and alloctonous sources through fluvial drainage. The spatial distribution of TOC through de lagoon was highest basically between stations 4 (Chantuto), 6 and 5 (Panzacola) with the highest values (7.64, 5.87, 4.95%, respectively); while station 1 (in the mouth and marine zone) was lesser (0.36%). The distribution of grain size was very heterogeneous between years, seasons and stations in the lagoon. Effect of torrential storm was found to significant with an increment to the sands in almost all lagoon system and the diminish of TOC. Sedimentation due to poorly planned water projects, deforestation, and slash-and-burn agriculture, dredging operations are impacting upon lagoon system jeopardizing the farming the shrimp and fishing in the are, affecting this productive ecosystem and the economy of a very important nucleus of fishermen. On November (2003) we detected total petroleum hydrocarbons in surficial sediments, due probably at the suspended dredging material. Contact Information: L. G. Calva Benítez. Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Hidrobiología, Lab. Ecosistemas Costeros (AS-224), Av. San Rafael Atlixco # 186, Col. Vicentina, 09340 Mexico City, Mexico, Phone: (55) 5804 4745, Fax: (55) 5804 4737, Email: [email protected]


16

Spatial and Temporal Variation of Porewater Variables in Mangrove Forests along the Shark River and Taylor Sloughs, South Florida E. Castaneda1, R. R. Twilley1, V. H. Rivera-Monroy1, K. de Mutsert1 and C. Coronado-Molina2

1Louisiana State University, Department of Oceanography and Coastal Sciences, Wetland Biogeochemistry Institute, Baton Rouge, LA, USA

2South Florida Water Management District, West Palm Beach, Florida, USA The spatial and temporal variation of porewater variables was monitored along the Shark River and Taylor Sloughs during 2001-2004. Porewater samples were collected in Shark River (SRS-4, SRS-5, SRS-6) and Taylor (TS/Ph-6, TS/Ph-7, TS/Ph-8) Sloughs during the dry and wet seasons. Measurements of porewater salinity, porewater sulfide concentrations, porewater nutrients, and soil redox potential (Eh) were measured at each site in the dry (May) and wet season (October). Soil Eh (0, 10, and 45 cm depth) was measured in situ using a multi-depth platinum probe attached to a Digi-Sense millivolt meter and a calomel reference electrode. Porewater samples were collected at 30 cm depth using a plastic siphon and syringe. One sample of pore water was assayed for salinity using a portable YSI salinity/conductivity/temperature meter. A second sample was added to an equal volume of antioxidant buffer in the field, then brought to the laboratory within 12 h to be analyzed for sulfide concentrations with a ORION sulfide electrode. A third porewater sample was filtered using a GF/F filter and stored frozen until assayed for ammonium (NH4+) and soluble reactive phosphorus (SRP). Porewater salinity in all sites was < 40 g kg-1 Porewater sulfide concentrations along the Shark River sites were overall below levels of detection compared to values along the Taylor sites, which ranged from 0.1 to 3.2 mM. Eh values were positive along Shark River due to frequent tidal exchange, in contrast to longer duration of inundation in Taylor sites. Porewater NH4+ concentrations were on average greater in Taylor Slough than in Shark River. Maximum and minimum average NH4+ concentrations were measured in TS/Ph-6 (46 µM), and in SRS-6 (< 1 µM) during the dry season of 2001 and 2003, respectively. Porewater SRP concentrations were similar in both areas during the dry and wet seasons, with values < 1 µM. Higher SRP concentrations (2 µM) were observed in SRS-6 during the wet season throughout the study period. These results suggest hydroperiod regulates the temporal and spatial variation of porewater variables in this area. Higher sulfide concentrations and lower redox potentials in the Taylor sites reflect the more permanent flooding conditions, in contrast to higher tidal exchange in the Shark River region. Therefore, the structure and function of mangrove forests of these two regions are regulated by a combination of gradients resources, regulators, and hydroperiod across the coastal gradient. Contact Information: Edward Castaneda, Louisiana State University, Department of Oceanography and Coastal Sciences, Wetland Biogeochemistry Institute, 3211 Energy, Coast and Environment Building, Baton Rouge, LA 70803, USA, Phone: 225-578-2773, Fax: 225-578-6423, Email: [email protected]


17

Comparison of Soil Phosphorus, Iron and Sulfur Pools in the Everglades/ Florida Bay Ecosystem Randy Chambers, Kristin Pederson and Mary Shockley

Keck Environmental Field Lab, College of William and Mary, Williamsburg, VA The south Florida landscape has changed dramatically over the last 100 years. Development of sub-tropical lands in Florida has accelerated as humans have changed water flows, drained wetlands, and opened up a world of agriculture, retirement villas and vacation getaways. Alteration of the native landscape has occurred in dramatic fashion, with loss of greater than 50% of the natural wetland area and profound disturbance of adjoining upland environments. Coupled with these human impacts are chronic, long-term impacts associated with sea level rise and acute, short-term impacts associated with hurricanes. The outcome is that the freshwater Everglades marsh-the largest remaining freshwater marsh in the contiguous United States-is lost to human development on the landward side, and to drowning on the seaward side. Given these different forcing functions, we are characterizing soils from different portions of the Everglades/Florida Bay ecosystem to: 1) track long-term changes in nutrient and mineral pools; and 2) determine the soil response to proposed restoration of freshwater discharge through the eastern portion of the Everglades. During summer 2003, soil samples were collected in triplicate to depths of 10 cm from 17 Long-Term Ecological Research (LTER) locations throughout the Florida Coastal Everglades system. Each core was sectioned into three depths and chemical extractions for phosphorus, mineral sulfides, and available iron were completed. The eastern Everglades with historically low water flows, long water residence times and stunted plant growth (Taylor Slough/Panhandle) averaged 2.93 ± 0.22 µmol P/cm3, compared to 5.19 ± 0.34 µmol P/cm3 from the western Everglades characterized by higher water flows, shorter residence times and more lush plant growth (Shark River Slough). Across three locations from Florida Bay, sediment P averaged 5.54 ± 1.32 µmol P/cm3. Based on sequential P extraction, more P was associated with inorganic calcium carbonate (~50%) than with inorganic iron oxides or organic matter (~25% each). Mineral sulfides were extracted from soils primarily as pyrite, relative to iron monosulfides. A significant difference in soil sulfide concentration was observed between sampling locations in freshwater marsh (7.41 ± 0.54 µmol S/cm3), mangrove forest (30.8 ± 3.5 µmol S/cm3) and seagrass meadow (20.1 ± 1.9 µmol S/cm3. Consistent with this pattern, available iron was highest in the freshwater marsh soils (13.8 ± 1.8 µmol Fe/cm3) and lowest in the sulfidic mangrove forest soils (9.61 ± 0.83 µmol Fe/cm3). These “snapshots” of nutrient and mineral pools in sediments establish a baseline across the south Florida landscape and serve to describe the antecedent conditions prior to increase in freshwater flows proposed for Everglades restoration. Contact Information: Randy Chambers, College of William and Mary, Keck Lab, Rm 101, Wake Drive, Williamsburg, VA 23187, Phone:757-221-2331, Fax: 757-221-5076, Email: [email protected]


18

Incorporating Socio-ecological Considerations into Environmental Restoration Efforts: Examples from the Florida Everglades D. L. Childers

Department of Biological Sciences and SERC, Florida International University, Miami FL Wetland biogeochemistry is often an important component of restoration efforts. Typically, these restoration efforts fail to consider the human dimension. The maturing field of ecological economics bridges this gap between biophysical and social science viewpoints, and the valuation of ecosystem goods and services is an example of this interdisciplinary coupling. The concept of ecosystem services is particularly relevant to efforts to restore or rehabilitate human-dominated wetlands. These projects are driven by important societal choices based on expectations for [real or presumed] ecosystem services to be delivered by the restored or rehabilitated wetland ecosystem. I argue that quantifying these ecosystem services-before, during, and after restoration-should be viewed as a critical component of these projects. This valuation goes beyond traditional economic cost-benefit analyses. The restoration, or rehabilitation, of the Florida Everglades provides an excellent case study for how the valuation of ecosystem services can aid the project itself by bringing together social and biophysical scientists. A key goal of this restoration project is to assure ample fresh water for a growing human population in south Florida. The roughly 6 million people currently living in south Florida consume about 1 billion m3 of water annually. 95% of this water comes from the Biscayne Aquifer via shallow wellfields along the western boundary of human development and the Everglades. This aquifer is largely recharged by the Everglades, and I argue that this purveyance of fresh water is the most important ecosystem service being provided by the Everglades. The current plan for Everglades restoration is based on providing up to 3 billion m3 of fresh water per year to a projected population of 15 million people by 2050. The plan places considerable importance on other water sources and storage mechanisms, suggesting the expectation that the Everglades alone will not be able to provide this ecosystem service to the future human population. I propose that several socio-ecological questions should be asked about the Everglades rehabilitation project (and about all major wetland restoration or rehabilitation programs). These include: 1) What are the values of ecosystem services that could be provided by a healthy Everglades? 2) What is the current and projected value of the fresh water supplied to human society by the Everglades? 3) If fresh water is a limiting resource in south Florida, then what human population can be sustained by a healthy, rehabilitated Everglades providing this ecosystem service? 4) What are the tradeoffs of and consequences for sustaining a rehabilitated Everglades if future human population is much larger than this? These and other questions are best answered [and asked] by an interdisciplinary approach and should be part of adaptive management of the Everglades Restoration project, and of any rehabilitation or restoration effort. Contact Information: Daniel L. Childers, Department of Biological Sciences and SE Environmental Research Center, Florida International University, University Park OE 236, Miami FL 343199, Phone: 3053483101, Fax: 3053484096, Email: [email protected]


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Molecular Characterization of Mangrove Vegetation and Sediment Cores from the Shark River Estuary, Florida Joshua B. Cloutier1, Rudolf Jaffe1,2 and Victor Rivera-Monroy3

1Department of Chemistry and Biochemistry, Florida International University, Miami, FL 2Southeast Environmental Research Center, Florida International University, Miami, FL 3Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Science, Louisiana State

University, Baton Rouge, LA Mangrove forests are major primary producers in the estuaries of South Florida. Mangroves play a vital role in the carbon and nutrient cycles of these areas, contributing large amounts of organic matter in the form of autochthonous litter fall and acting as a trap for allochthonous organic and nutrient inputs. The high rates of primary production and sedimentation within mangrove forests are important as they regulate the elevation of coastal wetlands in relation to seal level rise, and these conditions also favor the preservation of organic matter deposited in mangrove sediments. The adaptation of this halophytic species to survive in saline environments makes the mangrove a good indicator of coastal change, especially in systems where the hydrology (e.g. freshwater input) has been changed. Everglades National Park is currently the focus of the world’s largest wetland restoration effort. The hydrology of South Florida’s “River of Grass” has been drastically altered over the past 100 years to meet the needs of an exponentially growing population. As a result, the delivery of freshwater to the coastal regions has been substantially reduced, undoubtedly affecting the organic matter dynamics in the estuarine region. The goal of the restoration is to modify the quality, quantity, and timing of freshwater flow to recreate historical hydrological conditions; however an understanding of the biogeochemical cycling in the present state of the system and its variation over the past century is crucial in predicting the outcome of restoration. For this study, vegetation samples (senescent leaves and roots) of Rhizophora mangle, and sediment cores from the Shark River Slough were analyzed with the goals of (1) determining the major sources and potential historical changes of organic matter to the sediments, (2) identifying chemical markers to distinguish between mangrove leaf and root biomass-derived OM, and (3) to assess the extent of preservation of organic matter within the sediments downcore along a salinity/nutrient gradient. This will be attempted using geochemical proxies and biomass-specific molecular markers. Lipid biomarker analyses revealed differences in the n-alkane and terpenoid distributions between roots and leaves of R. mangle, and that fungi and cyanobacteria are contributing autochthonous sources of organic matter to mangrove soils/sediments. The abundance of a series of ring-A-degraded triterpenoids in root and sediment extracts suggests microbial activity within the sediments is high and may be closely associated with the below-ground biomass. Preliminary results from lignin phenol and 13C-NMR analyses show that after surficial diagenetic processes occur, the chemical signature of mangrove-derived OM is well preserved in the soils/sediments. Contact Information: Joshua Cloutier, Florida International University, Department of Chemistry and Biochemistry, CP 342, 11200 SW 8th Street, Miami, Florida 33199, USA, Phone: 305-348-3118, Fax: 305-348-3772, Email: [email protected]


20

Inference of Phosphorus Sorption Capacity in Southeastern Wetland Soils using Near Infrared Reflectance Spectroscopy (NIRS) Matthew Cohen, Mark Clark, Jeremy Paris and K. Ramesh Reddy

University of Florida, Wetland Biogeochemistry Laboratory, Soil and Water Science Department, Gainesville FL, USA

Isolated wetlands provide numerous ecosystem services to the landscape in which they are embedded. From a water quality perspective, wetlands provide a sink for various pollutants; in the Southeastern United States, the role of wetlands in regulating phosphorus flows is of particular importance. This study examined the capacity of wetland soils to sorb P using samples collected from 137 isolated wetlands throughout the southeastern US. A standardized isotherm experiment was developed to determine the soil P sorption capacity within each wetland; these data can be used to determine the vulnerability of a given wetland to P enrichment and can additionally be used to quantify the potential for P attenuation provided by each wetland in enriched areas. While isotherm data are valuable in this regard, prediction of sorption capacity from soil properties that are easier and less expensive to measure is necessary. The objective of this study is to develop a preliminary P-sorption index for wetland soils by relating observed isotherm data with other soil attributes; for this effort we use a suite of soil biogeochemical attributes (n = 28 including soil carbon, total N/P/C, metal cation concentrations using various extractions, pH), and also soil reflectance spectra, collected using a high-resolution (1 nm bands) spectrometer in the visual (350-750 nm) and near infrared (750-2500 nm) regions of the spectrum. Optical properties in this range have been used to predict a wide array of quantitative soil physical, chemical and biological properties through statistical model development. The advantages of using NIR spectra to predict of soil properties include low cost, high sample throughput, simple sample preparation and high analytical precision. P sorption for the soils used in this study ranged from -73 to 990 mg/kg. We used a suite of statistical models to relate soil properties to measured capacity (comparing biogeochemical attributes with NIR spectra); models were trained using 60% of the samples, and validated using the remaining 40%. We compared the standard error of prediction (SEP) and coefficient of determination (r2 between predicted and observed in validation) between models. The best biogeochemical model (SEP = 23 mg/kg, r2 = 0.75) was obtained using soil carbon, total P, Mehlich I Al, Mehlich I Fe and Mehlich I K as predictors. The model relating P sorption to soil reflectance spectra exhibited comparable accuracy (SEP = 27 mg/kg, r2 = 0.72). Given the significantly reduced costs and analysis time for collecting spectral data compared with biogeochemical characterization, we conclude that NIR spectra provide a powerful tool for characterizing, mapping and monitoring P sorption capacity of wetland soils. Contact Information: M. Cohen, University of Florida, Wetland Biogeochemistry Laboratory, Soil and Water Science Department, 106 Newell Hall, PO Box 110510, Gainesville FL 32611-0510, Phone: (352) 392-1804 x 348, Fax: (352) 392-3399, Email: [email protected]


21

Development of Heterotrophic Microbial Processes and Food Webs Following Salt Marsh Creation C. Craft1 and J. P. Megonigal2

1School of Public and Environmental Affairs, Indiana University, Bloomington, IN, USA 2 Smithsonian Environmental Research Laboratory, P.O. 28, Edgewater, MD, USA

Microbial processes and benthic invertebrate communities were measured along a chronosequence of 1 year-old to 28 year-old constructed Spartina alterniflora marshes to identify trajectories and rates of ecosystem development of heterotrophic food webs. Microbial processes related to carbon cycling (CO2 flux, methane production, denitrification) were significantly lower in young (<5 years old) constructed marshes (0.70-0.80 μmol CO2/g soil/sec, 0.4-0.5 femtomoles CH4 /g soil/sec, 7-14 ng N2O/g soil/day) as compared to older constructed marshes (1.0-2.3 μmol CO2/g soil/sec, 0.9-4.3 femtomoles CH4 /g soil/sec, 11-105 ng N2O/g soil/day) and natural marshes (1.0-3.8 μmol CO2/g soil/sec, 1.2-8.4 femtomoles CH4 /g soil/sec, 18-42 ng N2O/g soil/day). Young constructed marshes also contained significantly fewer benthic invertebrates (20-50 x 103 organisms/m2) than older constructed marshes (100-145 x 103 organisms/m2) and natural marshes (100-160 x 103 organisms/m2). Soil organic carbon was a powerful predictor of heterotrophic activity in both constructed and natural marshes. Using data from constructed and natural marshes, CO2 flux (r2=0.69), methane production (r2=0.56) and potential denitrification (r2=0.63) increased linearly with soil organic C. Density of benthic invertebrates increased asymptotically with SOC (r2=0.89). A threshold of 0.5-1% SOC was required for invertebrates to achieve equivalence to natural marshes. Soil organic C is a useful indicator to assess development of heterotrophic activity and food webs in constructed tidal marshes and in wetland restoration projects where ecosystem development follows primary succession. Most heterotrophic processes achieved equivalence to natural marshes within 5 to 10 years following marsh construction, the amount of time required to accumulate 1000 g organic C/m2 (0.5-1% C) and 100 g N/m2 (0.05-0.1% N) in the soil. Contact Information: School of Public and Environmental Affairs, Indiana University, Bloomington IN 47405, Phone: 812-855-5971, Fax: 812-855-7802, Email: [email protected]


22

Phosphorus Removal in a Constructed Wetland Dominated by Submerged Aquatic Vegetation S. Curtis1, J. White2 and M. Belmont2

1University of Florida, Soil and Water Science Department, Gainesville, FL 2 Louisiana State University, Wetlands Biogeochemistry Institute, Baton Rogue, LA

Phosphorus enrichment of the northern Everglades has prompted the U.S. Federal and Florida State governments to partner in reducing the P in surface waters entering the Florida Everglades. Stormwater Treatment Areas (STA’s) are large constructed wetlands in south Florida built primarily on agricultural land, designed to reduce the total phosphorus concentration in agricultural runoff entering the northern Everglades. Problems such as infilling with detrital/organic matter and phosphorus re-release during decomposition can be associated with emergent vegetation systems. Therefore, these treatment wetlands promote the biological removal of phosphorus by utilizing various species of both emergent and submerged vegetation. The effectiveness of phosphorus removal utilizing submerged aquatic vegetation was studied in a newly created system; STA 1 West, Cell 5b which is dominated by SAV. Water column, surficial sediments and vegetation samples were obtained from 120 stations within the 928 hectare treatment wetland during one of six samplings between August 2003 and May 2004. All samples were analyzed for total phosphorus (TP) while the water column samples also underwent analysis for dissolved organic phosphorus (DOP) and soluble reactive phosphorus (SRP). GIS maps, created from total P values, indicated preferential phosphorus uptake spatially within the wetland. Percent removal of TP, DOP, and SRP from the water column was determined utilizing the mean concentrations of the inflow and outflow stations. TP yielded a removal of 78% from an inflow mean of 0.146 mg L-1 to an outflow of 0.031 mg L-1. The inflow DOP averaged 0.030 mg L-1 and the outflow DOP was 0.015 mg L-1 yielding a 51 % reduction. SRP removal was 82% from 0.082 mg L-1 at the inflow to the outflow concentration of 0.015 mg L-1. These removal percentages are promising, in particular for SRP, and suggest that this submerged aquatic vegetation dominated STA is an effective alternative to traditionally emergent vegetation dominated treatment wetlands. Contact Information: S. Curtis, University of Florida, Soil and Water Science Department, Newell Hall Box 110510, Gainesville, FL 32608, Phone:352-392-1803, Fax: 352-392-3399, Email: [email protected]


23

Phosphorus Sorption Capacity and Exchange by Soils from Mitigated and Late Successional Bottomland Forest Wetlands E. M. D'Angelo1, A. D. Karathanasis1 and E. J. Sparks2

1Soil and Water Biogeochemistry Lab, Horticulture, Plant, and Soil Science Department, University of Kentucky, Lexington, KY, USA

2US Army Corps of Engineers, Eastern Kentucky Regulatory Office, KY, USA Bottomland hardwood forests (palustrine wetlands) are common types of wetlands found in broad floodplains in south central and southeastern US. Many of these wetlands are characterized as having medium to fine-textured soils with low organic matter (<5%), acidic pH (4-6), intermittent flooding, and deciduous vegetation dominated by oaks (Quercus spp.), sweetgum (Liquidambar styraciflua), river birch (Betula nigra), green ash (Fraxinus pennsylvanica), silver maple (Acer saccharinum) and hickory (Carya spp.). In the last two centuries, about 60% of the original 12 million ha of these wetlands were drained and converted to croplands for mostly corn and soybean production. In the last decade, some of these croplands in western KY were reclaimed as mitigated wetlands to compensate for losses of bottomland hardwood forests due to coal mining activities in the region. As a result of extensive agricultural management practices over many decades, many of these mitigated wetlands have lower amounts of organic matter, water-holding capacity, and anaerobic microbial populations compared to natural wetlands (D'Angelo et al. 2005, Wetlands). Since the wetlands are situated between agricultural uplands and streams and rivers, there is interest in determining the biogeochemical behavior and transport of N and P in these ecosystems and their potential influence on water quality. A central tenet of wetland mitigation is that replacement wetlands can sequester nutrients and perform other functions at the same level as natural wetlands. This study evaluated phosphorus (P) sorption capacity and P exchange in flooded soil microcosms obtained from eight early successional (ES) mitigated and eight late successional (LS) bottomland forest wetlands in western KY. The LS soils had three times greater capacity to remove and retain soluble inorganic P than ES soils, which was mostly due to higher amounts of amorphous aluminum (Al) oxides (oxalate extractable), organically-bound Al (CuCl2 extractable) and organic carbon in LS soils. Phosphorus exchange rates between the soil and water column were not significantly different in LS and ES microcosms, but rates in both systems were strongly related to the molar ratio of Mehlich III extractable P to Al + Fe in the soil (r2=0.64). Relationships between P sorption/exchange and wetland soil properties established in this study could be useful for (i) identifying suitable mitigation sites that would be P sinks rather than P sources to the water column and (ii) determining wetland replacement ratios that would fairly compensate for P retention capacity losses caused by destruction/alteration of bottomland hardwood forest wetlands. Contact Information: Elisa D'Angelo, Soil and Water Biogeochemistry Lab, Horticulture, Plant, and Soil Science Department, N 122 Agricultural Science Building, University of Kentucky, Lexington, Kentucky, USA 40546, Phone: 859-257-8651, Fax: 859-257-3655, Email: [email protected]


24

Landscape Level Assessment of Nutrient Limitation Using Plant Tissue Nutrient Ratios R. J. Daoust1,4, C. T. Nietch2, C. S. Hopkinson3 and J. T. Morris1

1Department of Biological Sciences, University of South Carolina, Columbia, SC, USA 2Water Quality Monitoring Branch, US Environmental Protection Agency, Cincinnati, OH, USA 3Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA, USA 4current address: BEM Systems, Inc., West Palm Beach, FL, USA

Stoichiometric approaches to ecology are rapidly gaining ground as scientists recognize their utility in understanding complexity in biological systems. Utilization of natural balances in chemical elements allows interpretation and understanding of ecological interactions on a variety of scales. Stoichiometric ecological approaches represent a feasible alternative to more traditional methods in investigating relationships between nutrient availability and macrophyte production by utilizing strong correlative relationships among plant tissue nutrient concentrations and measures of production or ecosystem function to infer degrees of nutrient limitation within ecosystems. Seagrass ecologists, expanding upon initial advances made by Redfield working on pelagic phytoplankton in the open ocean in the 1950’s, have demonstrated that tissue nutrient ratios can be utilized to assess nutrient limitation of species-specific plant production within ecosystems. Wetland ecologists working both in freshwater and coastal environments further expanded upon these ideas; linking production directly to tissue nutrient ratios to allow inference about how nutrient availability controls ecosystem structure and function. The majority of these studies, however, focused on specific species within an ecosystem or several species co-occurring within communities. Estuaries are particularly dynamic and complex places in which to seek understanding of landscape patterns of nutrient limitation and represent a new environ in which to expand upon existing stoichiometric approaches in ecology. We developed an equation-based graphical method to rapidly assess nutritional status in structurally and physiologically similar macrophyte species which allows calculation of several critical stoichiometric and ecological values and identifies zones of nutrient limitation which are broader in scope than previously defined ratio based limits. Utilizing existing data collected from the literature for seagrass leaf tissue nutrient concentrations we demonstrate the utility of the equation-based graphical method we developed in several species from multiple ecosystems. We further demonstrate how this approach can be effectively employed on a landscape level along a salinity gradient in the Edisto River spanning both freshwater and saltwater ecosystems through an analysis of several estuarine grass (Poaceae) and rush (Juncaceae) species. Analysis of these species utilizing the stoichiometry-based graphical method we developed allows strong differentiation in patterns of nutrient limitation among species within the estuarine landscape. Contact Information: R. J. Daoust, BEM Systems, Inc., 1601 Belvedere Road, Suite 305S, West Palm Beach, FL 33406, Phone: (561) 615-2210 ext 16, Fax: (561) 615-2490, Email: [email protected]


25

Losses of Nitrogen Through Various Mechanisms Under Flooded Rice Eco-System D. K. Das and Pintu Sur

Department of Agricultural Chemistry & Soil Science, Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal, India

Native as well as applied nitrogen undergo dynamic transformation in flooded rice eco-system. A series of reactions such as mineralization-immobilisation, ammonification, nitrification, denitrification, NH3-volatilization, leaching etc. are involved in the process of nitrogen transformation in soils and hence it its use efficiency by the rice towards production. Therefore, field experiments on kharif (wet season) and rabi (summer season) rice were conducted in an Aeric Haplaquept [pH, 7.6; organic carbon, 8.5 g/kg; CEC, 20.32 cmol(p+)/kg and total N, 0.89%] to evaluate the losses of N through various mechanism from flooded rice eco-system and their influence on rice yield. The experiment was laid out in a randomized block design with three replication consisting of seven treatments in each replication. After application of all the treatment materials to each of the plots 3-4 seedlings of 21 day old were transplanted and measured periodically the losses of N through various mechanisms. The results showed that the maximum amount of NH3 volatilization occurred in prilled urea (PU) basal treatment (18.9% in rabi and 16.5% in kharif over control) and such loss has been found to be reduced to 7.7% in rabi and 8.30 in kharif with green manure (GM) + PU application. Leaching and denitrification losses of nitrogen were found lowest, being 7.38 and 2.37% respectively with the PU as a split during both seasons. However, the total losses of N were recorded lowest in PU splits (18.78%) followed by GM + PU (19.85%) treatments irrespective of seasons which resulted higher yields f rice. The overall results concluded that applying PU as a split and GM + PU are the most efficient fertilization forms as they resulted in generally higher yields with relatively low total losses of N. Contact Information: D.K. Das, Bidhan Chandra Krishi Viswavidyalaya, Department of Agricultural Chemistry & Soil Science, Mohanpur 741 252, Nadia, West Bengal, 741 252, India, Phone: +91 33 2582 6150, Fax: +91 33 3582 8460, Email: [email protected]


26

Factors Affecting Tidal Creek Hydrodynamics and Materials Exchange Between Salt Marshes and Adjacent Bays of the Guadalupe Estuary (TX) Stephen E. Davis, III1 and J. Bryan Allison2

1Department of Wildlife & Fisheries Sciences, Texas A&M University, College Station, TX 2Department of Geology & Geophysics, Texas A&M University, College Station, TX

Freshwater inflow is an important part of the subsidy and maintenance of estuarine ecosystems. The bottom-up control of freshwater inflow on estuarine structure and function is poorly understood at higher trophic levels and likely varies across multiple scales of space and time. A proposed diversion of freshwater from the lower Guadalupe River led to a study of the factors affecting marsh ecosystem structure and function, particularly as they relate to the whooping crane (Grus americana)-an endangered bird that over-winters in the estuarine marshes around the Guadalupe Estuary. In order to predict the diversion’s impact, it is imperative to understand the factors governing crane territory quality. One way we are attacking this is by understanding the spatial variability in materials exchange between bays and marshes and investigating the factors that contribute to the marsh’s infrequent inundation patterns. The specific objective of this research is to quantify nutrient, suspended sediment, and floc exchange in three different tidal creeks in response to natural variations in tides, riverine inflows, wind forcing, and barge traffic. Our preliminary data indicate these natural and anthropogenic forces are all important in regulating salinity patterns, inundation regimes, and exchange of materials, but over dramatically different time scales. Barges affect tidal creek hydrodynamics and can mobilize sediment on scales of minutes. Wind forcing operates over slightly longer time scales (hours). Diurnal lunar tides are small (<10 cm) and, alone, are rarely large enough to inundate the marsh. However, fortnightly and semi-annual tides appear to be quite important in flushing the marsh and establishing connections with the numerous ponds that prevail across the marshes of this estuary. Thus far, our observations have shown a net input of sediment to the marsh at all three sites. Further, TSS concentrations have been positively correlated with salinity, indicating a bay source of this material. In general, floc exchange occurs over long time intervals (i.e. days to weeks), but barge traffic can result in noticeable exchange over a period of 10 minutes or less. The role of freshwater inflow is more difficult to assess in this system, as these marsh sites are distant from the mouth of the river and Guadalupe River inflow magnitude and duration varies widely throughout the year. Continued sampling over an array of inflow conditions over multiple years will help us to elucidate the role of riverine inflows in this system. Contact Information: Stephen E. Davis, III, Department of Wildlife & Fisheries Sciences, 2258 TAMU, Texas A&M University, College Station, TX 77843-2258. Tel. (979) 458-3475; e-mail [email protected]


27

A Review of Wetland Waste Water Assimilation in the Louisiana Coastal Zone John Day

Dept. of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA The use of wetlands for treatment of wastewaters has a number of important ecological and economic benefits. Adding nutrient rich treated wastewater effluent to selected coastal wetlands results in the following benefits: (1) improved effluent water quality; (2) increased accretion rates to help offset subsidence; (3) increased productivity of vegetation; and (4) financial and energy savings of capital not invested in conventional tertiary treatment systems. We present as case studies, results from several wetlands that are receiving secondarily treated wastewater in coastal Louisiana. At one site where sedimentation accumulation was measured, rates of accretion increased significantly after wastewater application began in the treatment site (from 7.8 to 11.4 mm yr-1), and approached the estimated rate of regional relative sea level rise (RSLR) (12.0 mm yr-1). No corresponding increase was observed in an adjacent control site. This suggests that the application of nutrient-rich wastewater can help coastal wetlands survive sea level rise. In the same site, surface water nutrient reduction, from the effluent inflow to outflow (1600 meters), ranged from 100% for NO3-N to 66% for total P. At a second site, a forested wetland that has been receiving wastewater effluent for 50 years, N and P were both reduced by more than 90%. Nutrient reduction is due to three main pathways: burial, denitrification and plant uptake. Dendrochronological analysis at the second site revealed that stem growth increased significantly in the treatment site after wastewater applications began, and was significantly greater than an adjacent control site. Similar increases in productivity have been measured in a number of wetland treatment sites. Economic analyses comparing conventional and wetland systems indicate savings range from $500,000 to $2.6 million. In addition there are substantial energy savings. Contact Information: John Day, Department of Oceanography and Coastal Sciences, School of the Coast & Environment, Louisiana State University, Baton Rouge, LA 70803, Phone: 225-578-6508, Fax: 225-578-6326, Email: [email protected]


28

Flux of Organic and Inorganic Nutrients in a Fringe Mangrove Forest in the Shark River Estuary, Florida, USA Robert R. Twilley1, Kim de Mutsert1, Victor H. Rivera-Monroy1, Edward Castañeda1, Melissa Romigh2 and Stephen Davis2

1Louisiana State University, Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Baton Rouge, USA

2 Texas A&M University, College Station, Texas, USA We evaluated fluxes of NH4, N02+NO3, PO4, Si, total phosphorus and total nitrogen in a fringe mangrove forest using the flume technique during the dry (May, December 2003) and rainy seasons (October 2003) in the Shark River Estuary, Florida, USA. The 11 m length flume extended through a fringe forest and was adjacent to a tidal creek discharging into the estuary. Nutrient concentrations were measured in both the flume and at the mouth of the tidal creek. Concentrations in the flume throughout the study period ranged from 0-5.2 µM (NH4), 0.0-3.5 µM (N02+NO3), 0.0-0.8 µM (PO4), and 41-103 2 µM (Si); and in the tidal creek from 0-4.0 µM (NH4), 0.2-2.7 µM (N02+NO3), 0-0.9 µM (PO4) and 53-141 µM (Si). A significant decrease in N02+NO3 and PO4 concentrations during 3-5 tidal cycles per sampling period and similar concentrations at both ends of the flume indicated that the flume spatial scale (28 m2) might not be adequate to evaluate net inorganic nutrient fluxes in this site. Similar trends in nutrient concentration in both the flume and at the mouth of the tidal creek also underscored the strong hydrological coupling between the forest and the adjacent estuary throughout the year. Measuring fluxes at the tidal creek scale (125 m2) might be more critical to correctly evaluate the role of mangrove forests as sink, source and transformers of nutrients in this estuarine system. Contact Information: Kim de Mutsert, Louisiana State University, Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Energy Coast and Environment Building 3211, Baton Rouge, LA 70803, USA, Phone: 225-578-2773, Email: [email protected]


29

Stormwater Treatment Areas for Everglades Protection: Capabilities and Limitations Thomas A. DeBusk, John Juston and Forrest E. Dierberg

DB Environmental, Inc., Rockledge, FL Six Stormwater Treatment Areas have been constructed in south Florida to treat agricultural runoff and eutrophic lake waters prior to entering the Florida Everglades. These treatment wetlands, ranging in size from 350 to 6,700 ha, were constructed by the South Florida Water Management District (SFWMD) at a cost of almost $1 billion. Each STA consists of two or more separate flow paths, which receive water in pulses, based on rainfall runoff and lake discharges from the upstream watershed. The original target outflow total phosphorus (P) concentration for the STAs was 50 µg/L, but this recently was substantially lowered, to at or near 10 µg/L. In order to better define the capabilities and limitations of the STAs for meeting this revised outflow TP target, we analyzed P removal data from individual STA flow paths for evidence of lowest achievable outflow P concentrations and for existence of mass load - outflow P relationships. We also performed internal sampling in several STAs to assess inflow-outflow profiles in water column chemistry. To date, the STAs have exhibited widely varying performance, with some systems providing outflow TP concentrations just above the 10 µg/L target, while others produce outflow concentrations consistently above 50 µg/L. Our analyses demonstrate that the “well-performing” STAs are best characterized by a history of mass P loading rates less than ~1.3 g/m2-yr. These well-performing systems demonstrated significantly lower outflow TP concentrations (12-20 µg/L), consistent mass removal efficiencies (~83%), and virtually no dynamic response to pulse-driven inflow P mass loads. However, the analysis also suggests that further reductions in STA P mass loads below this apparent threshold load will not necessarily reduce outflow P concentrations. Inflow - outflow sampling of well-performing STA flow paths under a range of hydraulic loading rates revealed rapid removal of soluble reactive P within the wetlands, but less effective removal of dissolved organic P and particulate P. Data from these profiles, coupled with analyses of outflow TP concentrations under low loading conditions, demonstrate that it will be very difficult for the STAs to achieve the 10 µg/L outflow TP target. Contact Information: Thomas A. DeBusk, 365 Gus Hipp Boulevard, Rockledge, Florida, 32955, USA, Phone: 321-639-4896, Fax: 321-631-3169, Email: [email protected]


30

Change in Nitrate Transfer in the Unsaturated Zone of the Soil according to the Duration of Flood Suppression in a Recently Reflooded Area (the Polder of Erstein East of France) S. Defraeye and M. Trémolières

Centre d'Ecologie Végétale et d'Hydrologie CEVH, Strasbourg, France The riparian zones of large rivers act as efficient filters for the retention or removal of nitrates flowing through these zones. Nitrogen (nitrate and ammonia) concentration in the unsaturated zone of alluvial soil varies during the vertical transfer through the soil / root system, in relation to the pulsation of the groundwater table. The intensity, the duration and the frequency of the aerobic and anaerobic phases govern the dynamics of the processes of transfer and biogeochemical transformations. The aim of this study is to analyse the changes of nitrate concentration in the soil solution during the transfer to the groundwater with the flood suppression and to specify the impact of the duration of isolation from the river. In the Alsace Rhine floodplain, the hydraulic management works of the Rhine, from the beginning of the 19th century to nowadays, has led to strong disturbances of the hydrological and hydrogeological functioning of the alluvial forest. The study site, the alluvial unflooded forest of Erstein is characterised by two adjacent sectors with contrasting durations of isolation from the river: 33 years in the internal sector (close to the Rhine) to 221 years in the external sector. Restoration of flooding was carried out. The forest of Erstein (named 'Polder') which can be reflooded since 2003, allows us to carry out a diachronic study of the functioning of the unsaturated zone after reflooding and the resilience of the biogeochemical processes characteristic of an alluvial zone. Four stands were selected according to the geomorphology (channel / terrace), the degree of isolation (internal sector / external sector) and the level and intensity of floods (upstream-south / downstream-north). They were equipped with porous ceramic cups and tensiometers at different levels down to the groundwater. The results show that the removal of the Rhine floods and the consecutive reduction of the groundwater variations cause a significant reduction of the nitrate removal capacity. This functional change results in a space-time decrease of denitrification versus nitrification, which is particularly high in the sandy soils of the external sector. Nevertheless, denitrification still exists in the hydromorphic soils in the north (downstream part) of the internal sector and in the clay-muddy soils of the cut-off drainage channels. Two main factors can explain this difference. On the one hand, the dynamics of the water table is higher along the Rhine related to a persistent exchange between Rhine water and groundwater while on the other hand, the shorter duration of isolation of the internal sector produces deposits and conservation of a higher percentage of fine sediments. The Polder of Erstein was reflooded for the first time in January 2004, for two days with a volume of around 3 million m3 on more than 70% of its total surface. The main consequences of soil saturation by water with a relatively low nitrate concentration (around 12 mg/L) were dilution of soil solution in the external sector and an increase of nitrate transfer to the groundwater in the internal sector. Contact Information: S. Defraeye, Centre d'Ecologie Végétale et d'Hydrologie CEVH, MA 101 ULP, ENGEES, 28 rue Goethe, 67083 Strasbourg, France, Phone: +33 3 902 41 875, Fax: +33 3 902 45 371, Email: [email protected]


31

An Evaluation of Two Tracers Commonly Applied to Surface-Flow Wetlands: Rhodamine-WT and Lithium Forrest E. Dierberg and Thomas A. DeBusk

DB Environmental, Inc., Rockledge, FL Rhodamine-WT and LiCl are two commonly used tracers for hydraulic investigations in surface-flow wetlands. Using outdoor mesocosms, we found lithium to be more conservative than rhodamine-WT when initial concentrations were 4.9 to 64 µg/L for rhodamine-WT and 28-516 µg/L for Li+ (1:6 to 1:8 (wt/wt) ratio of rhodamine-WT to Li+). At higher initial concentrations (i.e., 100 µg/L for rhodamine-WT and 1000 µg/L for Li+), both tracers returned more than 95% of the injected amount in submerged aquatic vegetation-dominated mesocosms; rhodamine-WT was returned at only 74-75% in cattail-dominated mesocosms. Batch studies using different sediment substrates exposed to direct sunlight and shade indicated Li+ was less affected by adsorption and microbial processes than was rhodamine-WT at low initial tracer concentrations of each (4.9 and 19.4 µg/L for rhodamine-WT and 28 and 106 µg/L for Li+). Both rhodamine-WT and Li+ desorb back to the water column in low amounts. The extent of adsorption losses by rhodamine-WT depended on the organic matter content of the sediment and the extent of photolysis. Even though rhodamine-WT was not as stable as LiCl at initial concentrations less than 60 µg/L, the reduction in the recoveries did not affect the accuracy of key hydraulic parameters (hydraulic retention time, tanks-in-series number) derived from the method of moments analysis as long as a discernible concentration-time response still existed. This is because the tracer losses were approximately zero-order and irreversible. Contact Information: Forrest E. Dierberg, 365 Gus Hipp Boulevard, Rockledge, Florida, 32955, USA, Phone: 321-639-4896, Fax: 321-631-3169, Email: [email protected]


32

Can the Wetlands Save the Lake? The Role of a Constructed Wetland in Protecting the Water Quality of Lake Waco R. Doyle, T. Scott and T. Conry

Center for Reservoir and Aquatic Systems Research, Baylor University & City of Waco, Waco, TX. USA. The North Bosque River watershed in Central Texas may be among the most contentious and intensively studied watersheds in North America. This 4,150 km2 watershed provides about 75% of the water to Lake Waco, the drinking water supply reservoir for the City of Waco, TX. In recent years the reservoir has experienced rapid eutrophication with planktonic chlorophyll-a levels averaging about 15 mg m-3 and often exceeding 25 mg m-3. Taste and odor problems in the finished drinking water supplied from the reservoir have also become more frequent and intense. Although numerous factors are certainly involved, the increasing dairy operations in the watershed have been implicated as one of the major contributors to nutrient inputs fueling these changes. Recently, as part of the habitat mitigation package related to a 2.13 m rise in the conservation pool of the reservoir, the City of Waco has built a 75 ha off channel wetland adjacent to the transition area between the North Bosque River and Lake Waco. Electrical pumps divert 23 million L per day (6 MGD) of water from the river into the wetland. The nominal retention time of the reservoir is approximately 10 days before the water rejoins the river. The wetland was created for both habitat and water quality benefits. Routine water quality monitoring of the water flowing through the wetland clearly demonstrates the initial effectiveness of this constructed wetland to remove nitrogen and phosphorus from the water. The majority of the removal occurs in the initial portion of the wetland, resulting in a strong nutrient depletion gradient within the wetland. In addition, the efficiency of removal of N and P is unequal, with N being removed with higher efficiency than P. This removal imbalance results in significant N:P shits of total and available nutrients as the water flows through the wetland. This persistent nutrient gradient and spatial change in nutrient stoicheometry have significant impacts on periphyton and metaphyton within the wetland. Also, the ultimate assimilative capacity of the wetland for N and P are not yet known, but is the object of ongoing investigations. Contact Information: Robert Doyle, Center for Reservoir and Aquatic Systems Research, One Bear Place #97388, Waco, TX 76798, Phone: 254-710-2911, Fax: 254-710-2969, Email: [email protected]


33

Wetland N and P Dynamics along a Gradient of Vegetation Productivity and Soil pH R. Merckx1 and M. Drouillon2

1Catholic University of Leuven, Lab for Soil and Water Management, Heverlee, Belgium 2Hogeschool West-Vlaanderen, Department of Industrial Engineering and Technology, Kortrijk, Belgium

Relationships between vegetation composition, vegetation characteristics (nutrient contents, biomass production in summer and winter), soil nutrient availability indices (in situ nutrient contents, potential nutrient release rates) and soil characteristics (thickness of O, A and H horizons, pH, total C, P and N) were examined in 15 wetlands throughout the growing season of 1999. The 15 wetlands were situated in Flanders, Belgium, and included wet heath ecosystems, wet nutrient-poor meadows, small-sedge and tall-sedge fens and reed stands. The wetlands were selected to constitute a gradient in vegetation productivity (biomass in summer: 246 ± 159 - 1597 ± 142 g m-2) and pH (3.7 ± 0.1 - 7.6 ± 0.1). The hypothesis that sites with large available nutrient pools are characterized by large nutrient fluxes, was only confirmed in one case: vegetation N and P contents (pools) related positively with potential soil NH4-N and soil anion exchange membrane extractable P (AEM-P) release rates (fluxes). Potential NO3-N release rates did not relate to any of the nutrient availability indices. Three classes of wetlands were identified using the difference between summer and winter biomass (biomass accretion): (1) ≥ 800 g m-2 (‘Large’); (2) 800 g m-2 > biomass accretion ≥ 350 g m-2 (‘Medium’); (3) < 350 g m-2 (‘Small’). Multiple discriminant analysis yielded in situ AEM-P and management intensity as discriminating parameters between small and medium versus large accretion sites. Soil NH4-N release rates, number of red list species, management intensity, O horizon thickness, pH, acid hydrolyzable P and total soil P separated small versus medium and large accretion sites. These three wetland classes returned when combining vegetation composition and the before mentioned parameters in a constrained canonical analysis (CCA). The first two CCA axes were determined by (1) pH and winter biomass and (2) in situ soil AEM-P content in peak summer, vegetation cover percentage and height. Acid hydrolyzable P was significant in explaining species composition at oligotrophic and mesotrophic sites (small and medium biomass accretion). In contrast, AEM-P was only significant at mesotrophic and eutrophic sites (medium and large biomass accretion). In situ soil NH4-N in spring and AEM-P in peak summer significantly increased the proportion of variance of species composition explained by general soil and vegetation characteristics (P < 0.05), in contrast to potential nutrient release rates. These observations illustrate (1) that the relevance of P availability indices is ecosystem-dependent and (2) the need of a diversified monitoring approach, not only with regard to the choice of monitoring parameters, but also with regard to the sampling time for a certain parameter. Contact Information: M. Drouillon, Hogeschool West-Vlaanderen, Department of Industrial Engineering and Technology, Graaf Karel de Goedelaan 5, 8500 Kortrijk, Belgium, Phone: +32-56-241211, Fax: +32-56-241224, Email: [email protected] or @gmail.com


34

Factors Affecting Metal Mobility and Bioavailability in Intertidal Sediments of the Scheldt Estuary G. Du Laing, D. Vanthuyne, F. M. G. Tack and M. G. Verloo

Ghent University, Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent, Belgium Greenhouse experiments and field monitoring were conducted to assess the major factors affecting metal mobility and bioavailability in intertidal sediments of the Scheldt estuary (Belgium and The Netherlands). In the greenhouse experiments, sediments were subject to various influences. In some treatments, varying amounts of salts or organic matter were added. Other treatments involved subjecting sediments to different flooding regimes. Finally, some tanks were planted with reed and willow to assess differences in metal uptake by the vegetation and effects of plants on metal mobility. Treatments were applied in tanks filled with metal contaminated sediments and equipped with drainage outlets at the bottom. The sediments were selected to represent a range of characteristics, such as initial redox conditions, organic matter content, salinity, texture. The field observations included monitoring pore water chemistry, metal contents in plants and ground-dwelling invertebrates, sediment quality and characteristics in selected intertidal zones. Metal concentrations in pore water and sulphide contents in the sediments during field monitoring and greenhouse experiments suggested that reduction of Fe/Mn-oxides and the formation of sulphides were major processes determining metal mobility and bioavailability in intertidal sediments. Flooding regime, initial redox conditions and the availability of easily biodegradable organic matter affected the rate of Fe/Mn-oxide reduction, sulphide formation and metal mobility. Salinity seemed to affect especially cadmium mobility and bioavailability. Cadmium contents in reed plants and ground-dwelling spiders increased with salinity, despite markedly lower sediment total metal contents in the high-salinity sites. This could be attributed to a combination of higher cadmium concentrations in the pore water and changing cadmium speciation with increasing salinity. Flooding regime and redox conditions, organic matter contents and salinity significantly affected metal mobility and bioavailability in intertidal sediments of the Scheldt estuary. Acknowledgements: The authors are indebted to Ghent University and the Belgian Science Policy Office for

financing this research.

Contact Information: G. Du Laing, Laboratory for Analytical Chemistry and Applied Ecochemistry, Department of Applied Analytical and Physical Chemistry, Ghent University, Coupure Links 653, B-9000 Gent, Belgium, Phone: +32-9-2645995, Fax : +32-9-2646232, Email: [email protected], Web Site: http://www.ecochem.ugent.be


35

Metal Accumulation in Intertidal Litter through Decomposing Leaf Blades and Stems of Phragmites australis G. Du Laing1, G. Van Ryckegem2, F. M. G. Tack1 and M. G. Verloo1

1Ghent University, Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent, Belgium 2Ghent University, Laboratory for Botany, Ghent, Belgium

This study aimed to assess the role of decomposing reed plant material in wetland metal cycles. Metal contents of decomposing leaf blades and stems of reed plants (Phragmites australis) were monitored by a standard litter bag method in an intertidal zone of the Scheldt estuary (Belgium). Plastic litter bags were filled with leaves and cut culm sections and anchored on the sediment. On monthly intervals 2 litter bags of leaves and culms were retrieved from the marsh. Samples were gently but thoroughly rinsed with distilled water to remove adhering clay and macro-invertebrates. Stems and leaf sheaths were separated and processed separately during the entire study. All samples were dried, weighed and analysed for ash and Cd, Cu, Cr, Ni, Pb and Zn contents. Most concentrations increased considerably during the decomposition. Generally, also a very important net metal inflow could be observed. The inflow was highest for leaf blades. Increases of the metal contents could be attributed to different factors, such as contamination by sediment particles, passive sorption onto recalcitrant organic fractions and active accumulation by e.g. microbial colonizers. High correlations between ash contents and metal concentrations for leaf blades suggest that the increase of leaf blade metal contents can be due to an important infiltration of mud particles, which were not removed by rinsing the leaf blades with distilled water preceding the analyses. The metal concentration in the inflowing ash fraction was also estimated and found to be extremely high for most of the elements during the first month. After the first month, it decreased substantially and remained relatively stable. The inflow of ash with higher metal concentrations during the first month could be attributed to combined trapping of mud particles and a faster physicochemical sorption of dissolved metals onto the remaining organic matter. This hypothesis is strengthened by the fact that simultaneous leaching of K was observed during the first month suggesting metal exchange at the litter surface. This was also observed for the stems. However, smaller amounts of inflowing ash and even outflowing ash amounts, were found during the remainder of the experiment, which suggests that inflow of inorganic particles is not the major factor determining metal accumulation by stems on medium term. Other mechanisms such as active accumulation by microbial organisms could be more important. To test whether metal accumulation could be due to incorporation by microbial litter colonizers, correlations between metals and fungal biomass (ergosterol concentrations) within the same plant litter were determined. No significant correlations were found for leaf blades. However, fungal dynamics proved to be highly correlated with metal contents in stem tissue except for Cr and Zn, both elements of which the contents stayed relatively stable during the experimental period. To clear out which mechanisms could drive metal accumulation under influence of microbial decomposers, more specific research is needed. Contact Information: G. Du Laing, Laboratory for Analytical Chemistry and Applied Ecochemistry, Ghent University, Coupure Links 653, B-9000 Gent, Belgium, Phone: +32-9-2645995, Fax : +32-9-2646232, Email: [email protected], Web Site: http://www.ecochem.ugent.be


36

Metal Pore Water Concentrations as affected by Soil Redox Status and Moisture Regime D. Vanthuyne1, G. Du Laing1, J. Wustenberghs1, B. Vandecasteele2, F. M. G. Tack1 and M G. Verloo1

1Ghent University, Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent, Belgium 2Institute for Forestry and Game Management, Geraardsbergen, Belgium

A greenhouse experiment was conducted to determine the combined effect of initial redox status of a metal polluted dredged sediment derived soil and changing moisture regimes on pore water metal concentrations in the upper soil layer. Oxidized (Ox) soil (500 mV) and reduced (Red) soil (-250 mV) was collected at a dredged sediment disposal site and divided over 2 recipients to subject the soils to 2 different flooding regimes: field capacity (F) and permanently flooded (P). Treatments subsequently will be referred to as Ox - F, Ox - P, Red - F and Red - P. Pore water was extracted using Rhizon MOM soil moisture samplers (Eijkelkamp, Giesbeek, NL), installed horizontally 5 cm below the soil surface. The pore water samples were analysed for metals (Cd, Cu, Ni, Fe, Mn, Pb, Zn), anions (Cl-, NO3

-, SO4-) and total organic carbon content. At the same

depth, the redox potential was measured. The soil characteristics (pH, OC- and CaCO3-content, texture, AVS and metal content) were determined before and after the test. Initial pH (7), CaCO3 content (14%), OC (5%), and texture (silty clay) were similar between the oxidized and reduced soil. Initial sulphide was absent in the oxidized soil, and 1.6 g S2- kg-1 DM in the reduced soil. The redox potential of the two flooded soils (P-treatments) after 20 days was as low as -250 mV. In the oxidized soil at field capacity (Ox - F) it varied between 300 and 500 mV. In the reduced soil at field capacity (Red - F), the redox potential remained fairly constant and still remained as low as the two flooded soils after 140 days. Despite fairly constant redox potentials, pore water metal concentration of the different regimes varied significantly. The reduction of Fe/Mn-oxides appeared to be a major process determining metal mobility in the permanently flooded oxidized soil, whereas precipitation of sulphides seemed dominating in the permanently flooded reduced soil (Red - P). Release of Mn concurrent with oxidation of sulphides was reflected in the soil solution at field capacity after about 100 days. Kinetics of Ni mobilization were similar to those of Mn. Continuously high Zn concentrations were observed in soil Ox - F, but decreased in the corresponding permanently flooded soil (Ox - P). For both initially reduced soils, Zn concentrations were continuously low. An increase however was observed after about 100 days for Red - F, coinciding with the initiation sulphide oxidation. A similar behaviour was observed for Cd and Cu. Cd and Cu concentrations in Ox - P in contrast decreased much faster and Cu mobilization between day 100 and the end of the experiment (day 140) was not yet observed. The results indicate that measured redox potential alone is not a sufficient indicator for the various processes that control metal pore water concentrations when a soil is subject to changing moisture regimes. Acknowledgements: The authors are indebted to the Belgian Science Policy Office for financing this research. Contact Information: G. Du Laing, Ghent University, Laboratory of Analytical Chemistry and Applied Ecochemistry, Coupure Links 653, 9000 Ghent, Belgium, Phone: +32-9-2645995, Fax: +32-9-2646232, Email: [email protected], Web Site: http://www.WETMAT.UGent.be


37

Phosphorus Storage by Historically Isolated Wetland Ecosystems within Grazing Pastures of Okeechobee Basin, Florida E. J. Dunne, M. W. Clark and K. R. Reddy

Soil and Water Science Department, University of Florida/IFAS, Gainesville, FL Wetlands can be a dominant landscape feature of agricultural watersheds. Isolated wetlands, which are often described as wetlands that have no permanent connections to other surface water bodies are a common feature of grazing pastures within the four priority basins of Okeechobee Basin. These historically isolated wetlands (as they are now partially drained) cover about 11% of the four priority basins. These basins are dominated by agriculture and contribute a disproportionate amount of the phosphorus (P) entering Lake Okeechobee. At present, the hydrological restoration of these historically isolated wetland ecosystems is being evaluated as a potential Best Management Practice (BMP) to help reduce P loads to the lake. The purpose of our study is to initially characterize on a site specific basis the wetland ecosystem P storage components such as soil, below ground biomass, litter and live vegetation and determine the effect of hydrological restoration on within system P cycling of isolated wetland ecosystems. Paired wetlands (one of which will undergo hydrological restoration, while the other will not) are located at both the Larson Dixie and Beaty ranches. Prior hydrological restoration, initial site soil characterization suggests that sites have similar soil P levels ranging between 12.4 ± 6.12 and 16.99 ± 8.54 mg TP m-2. Although wetland centers (those areas dominated by open water, Pontedaria cordata, and Polygonum spp.) generally stored more total P (331 mg P kg-1) than wetland edges (dominated by Juncus effusus) (225 mg P kg-1) and/or surrounding uplands (dominated by Bahia spp. and other forage grasses) (176 mg P kg-1) this was not the case when values were normalized for bulk density and sampled soil depth. When zones were compared on a g TP m-2 basis, there was no significant difference, suggesting that TP storage in wetland centers was predominantly controlled by organic components, as evident from the higher loss on ignition (LOI) and lower bulk density, whereas wetland edges and surrounding uplands had increasingly higher bulk densities and lower LOI. Below ground biomass, litter and live vegetation will also be characterized for each of the wetland ecosystems prior and during hydrological restoration in an effort to monitor ecosystem change, as a response to hydrologic restoration. Also, three transects within each wetland were set up that extend from wetland centers to surrounding uplands in an effort to represent a hydrological gradient from flooded to dry conditions. Soil samples (0-10 cm) and vegetation characteristics were also collected and will be collected on a regular basis pre and during restoration such that soil and/or vegetation responses along the hydrologic gradient can be determined during the monitoring period. Contact Information: E. J. Dunne, Soil and Water Science Department, University of Florida/IFAS, 106 Newell Hall, P.O. Box 110510, Gainesville, FL 32611, USA, Phone 352-392-1804 x 348, Fax: 352-392-1804-3399, Email:[email protected]


38

Phenol Oxidase as a Regulator of Atmospheric Carbon Sequestration and Bioremediation in Wetlands Chris Freeman

School of Biological Sciences, University of Wales, Bangor, UK Many of the unique properties of peat accumulating wetlands, such as their ability to preserve intact ancient human remains and to store globally significant quantities of atmospheric CO2, can be attributed to the low rates of enzymic decomposition in these systems. Wetland soils are normally devoid of molecular oxygen in all but the uppermost layer, and thus enzymes such as phenol oxidase, which require molecular oxygen for their activity, are rarely found to be active. But interestingly, even the activities of hydrolase enzymes that do not have an oxygen requirement, are impaired in these wetlands. Recent research suggests that those low hydrolase activities can be indirectly attributed to constraints on phenol oxidase. Without oxygen, phenol oxidase activity is impeded and phenolic materials can accumulate in the wetland soil. The wider implications of this observation can be found in numerous studies that have shown that phenolic materials are highly inhibitory to microbes and their enzymes. Thus, oxygen constraints upon phenol oxidase can severely impair decomposition as a whole. This mechanism may have important implications, not only for the preservation of archaeological organic materials, but also sequestration of atmospheric CO2 and the treatment of water pollution. For the latter, treatment wetlands in which plant assimilation is a major contributor to the treatment process are particularly favored by the mechanism, for the suppression of enzymic decomposition helps to retain the pollutants within the plant remains. Contact Information: Chris Freeman, School of Biological Sciences, Memorial Building, Deioniol Rd, Bangor, LL57 2UW, Phone 44-1248-351151, Fax: 44-1248-370731, Email: [email protected].


39

The Role of Wetland Trees in Element Cycling and Dispersal, Sky Lake, Mississippi Stan Galicki1, Gregg R. Davidson2 and Stephen R. Threlkeld3

1Department of Geology, Millsaps College, Jackson, MS 2Department of Geology and Geological Engineering, University of Mississippi, University, MS 3Department of Biology, University of Mississippi, University, MS.

Wetlands are typically regarded as chemical buffers between agricultural lands and open water environments. Nutrients and trace elements migrating through the wetland are expected to experience delayed transport and at least temporary sequestration through uptake into plant tissue or adsorption to wetland sediments. In Sky Lake, an oxbow lake in Mississippi surrounded by a vegetated fringe dominated by century old bald cypress (Taxodium distichum (L.) Rich), the migration of several trace elements appears to be facilitated through the wetland and into the open water environment. Sediment cores collected from an open water region near the center of the lake contain higher concentrations of As, Fe, P and Pb than cores collected from two areas within the vegetated fringe. Lead in particular shows a large spike in the open water cores in sediments dating from the late 1920’s to early 1930’s. The spike is completely absent in all cores from the vegetated fringe. The higher concentrations in the open water cores are not readily explained by differences in organic or clay content, or by significantly different rates of sediment accumulation. The sediment accumulation rate in the open water area, based on 210Pb and 137Cs measurements, is similar to the rate estimated for one of the two vegetated fringe areas. The higher concentration, and the presence of the Pb peak only in the open water sediments, appears to be related to element cycling within the vegetated fringe. Two possible explanations are currently under consideration. First, wetland trees may remove newly deposited elements, some of which will be transported to foliage that is annually shed back to the wetland floor. As the litter decays, some portion of the element load is transported out into open water and deposited. With no plants to recycle the elements in this area, the elements become sequestered and preserve a record of historical influxes. A second related possibility is that elements delivered to the wetland become directly adsorbed onto existing litter. Decay and remobilization will carry a portion to the open water where it is deposited and sequestered. Both possibilities should result in at least small increases in the Pb concentration in sediments within the vegetated fringe, but none have been observed. In either scenario, wetland trees, via the production of annual litter, play a significant role in the dispersal of elements in the wetland. The interpreted historical record of element use may be preserved or obscured based on the selection of core locations within the wetland. Contact Information: S. Galicki, Millsaps College, Department of Geology, Jackson, Mississippi, USA, Phone: 601-974-1340, Fax: 601-974-1345, Email: [email protected]


40

Marsh Plant Growth Response and Metal Uptake from Amended Red Mud Substrates in Greenhouse and Field Studies Robert P. Gambrell1, Cale LeBlanc2, Norman Murray3 and Lorna Putnam1

1Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA 2Conestoga-Rover and Associates, Baton Rouge, LA 3Norman Murray and Associates, Covington, LA

Red mud is a by-product of the aluminum industry that has long been considered a waste material requiring expensive disposal methods. It is the material remaining after aluminum has been extracted from bauxite ore. Red mud may offer some productive-use potential for coastal marsh restoration or other land restoration because of its soil-like properties and the large quantities produced annually by aluminum refineries which are often located near coastal areas. However, two problems must be overcome. The first is that red mud, by itself, does not support good plant growth. The most likely reasons are lack of certain nutrients, the usually high pH from the residual alkali used in the extraction process that is only partially neutralized before disposal, and possibly the presence of toxic materials. The second problem is the risk of trace and toxic metals found in red mud being released to interstitial water and/or being taken up by plants at restoration sites. Some bauxite ores are substantially elevated in Mn, Cu, Zn, Pb, Cr, Ni, and Cd compared to typical soils. Initial short-term laboratory and greenhouse studies previously reported indicated when red mud is amended with coastal marsh soil or sediment, saltwater marsh plant growth was greatly improved and metals uptake by plants or metals release to interstitial water was minimal. This is a report of follow up greenhouse and field-constructed wetland plot studies examining additional substrates (some natural and others waste products) that might be mixed with red mud to achieve good plant growth. Also, plant uptake of trace and toxic metals was monitored for more extended periods in the greenhouse, and, included entire growing seasons in constructed wetlands plots in a field site simulating natural tidal cycles. These expanded follow up studies based on results of earlier work continue to demonstrate that red mud can be amended with a number of substrates to support good plant growth, and that very little of the excessive levels of trace and toxic metals present in red mud is available for plant uptake. Contact Information: R. P. Gambrell, Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA 70803, Phone: 225-578-6426, Fax: 225-578-6423, Email: [email protected]


41

An Assessment of Historical Vegetation Change and Organic Matter Preservation in Freshwater Wetlands of the Florida Everglades: A Biogeochemical, Multi Proxy Approach Min Gao1, Colin Saunders2, Dan Childers2 and Rudolf Jaffé1

1Florida International University, Department of Chemistry and Biochemistry, Miami, FL, USA 2Florida International University, Department of Biology, Miami, FL, USA

Over the past 200 years, more than 50 percent of the wetlands in the U.S. have been lost and many of those remaining are degraded. Wetlands provide important services such as shoreline protection through organic matter accumulation, storing and filtering of toxic compounds, habitat for fish and wildlife, and exports of organic nutrients to estuarine ecosystems. Freshwater wetlands of the South Florida Everglades have changed considerably due to natural variability and human management of hydrology, fire regimes, and nutrient loadings. The goal of the Comprehensive Everglades Restoration Plan (CERP) is to restore the South Florida hydrology to historic conditions. However, predicting how the current system will respond to restoration efforts is a big challenge. It is hypothesized that the increased freshwater flow will bring about changes in organic matter dynamics of ENP (Everglades National Park) and alters vegetation dominance, among other ecological changes. Therefore, understanding paleo-environmental vegetation change, and the current and historical organic matter sources and dynamics in Everglades’ freshwater marshes, is critical to predicting the ecological and geochemical responses of the current system to increased freshwater flow and nutrient conditions. In this work, vegetation samples, surficial soil/sediment samples and cores were taken from the two major drainage systems of ENP, namely Taylor Slough and Shark River Slough, with two main objectives: (1) to cross correlate ecological and geochemical parameters for application in wetland paleo-ecological studies; and (2) to determine the sources of organic matter as well as the extent of its preservation using multiple geochemical approaches including biomass-specific molecular markers, lignin phenol composition, 13C-NMR and optical properties of extractable humic substances. These parameters, coupled with a vegetation survey of current ecosystems (surface samples for wet prairies and freshwater marsh ecosystems) and vegetation-specific seed data from soil cores, suggest that: (1) the organic geochemical proxies used here can be utilized to assess wetland ecosystem changes due to natural and human influence; (2) the vegetation dominance changed from more Eleocharis-dominated wet prairies to more Cladium-dominated freshwater marshes after the drainage of ENP; and (3) due to highly oligotrophic conditions, the organic matter was preserved well and most diagenetic transformations occur on the soil surface. Contact Information: Min Gao, Florida International University, Department of Chemistry and Biochemistry, 11200 SW 8 Street, Miami, FL 33199, USA, Phone: +1-305-348-3118, Fax: +1-305-348-3772, Email: [email protected]


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Effects of Vegetation Type on Soil Accrual and Phosphorus Stability in Wetlands Receiving Agricultural Drainage Kevin A. Grace1, Forrest E. Dierberg1 and John R. White2

1DB Environmental, Inc., Rockledge, FL 2Wetlands Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA

Phosphorus (P) stability was investigated in wetland soils that accrued during treatment of agricultural drainage waters and stormwater. Soils were collected from a continuously flooded, flow-through treatment wetland in south Florida that contained both emergent (Typha) and submerged (Najas guadalupensis) vegetation communities. Soil accrual depths after eight years of wetland operation were similar for the two communities, with mean (± one standard deviation) depths of 9.9 ± 2.5 cm in cattail stands and 10.8 ± 5.1 in adjacent submerged macrophyte beds. Inorganic P stored in labile forms (NH4Cl-extractable and NaOH-extractable) was also similar between surface (0-4 cm) soils from the two community types (mean labile P, 76 ± 15 mg/kg). However, differences were observed in total P, total Ca and HCl-extractable P, suggesting that stable Ca- and Mg-bound P forms were accruing faster within submerged macrophyte beds than within cattail stands.

We also observed that the original agricultural muck soils underlying the cattail stands differed markedly from the original soils beneath the submerged macrophytes. The muck soil beneath the newer wetland soil within a cattail stand was P-depleted (168 ± 94 mg P/kg), while in areas containing submersed vegetation the buried muck was P-enriched (500 ± 212 mg P/kg) relative to pre-flooded muck soils (358 ± 35 mg P/kg). Not only was the TP content of the original soil affected by cattail colonization, but we also observed differences in porewater soluble reactive phosphorus (SRP) concentrations. The mean concentration of SRP in porewater within a stand of cattails was 33 ± 28 µg/L, consistently lower than within the soils 1 m (364 ± 291 µg/L) and 5 m (243 ± 145 µg/L) away from the stand.

Both the depleted P content in the underlying muck soils and the lower porewater SRP concentrations within cattail communities indicate that “P mining” occurs within the cattail rhizosphere. This implies potential export of previously stored soil P to the water column as cattail detritus. Furthermore, our fractionation data demonstrate that lower amounts of P stable forms of P are stored in newly accreted wetland soils within cattails.

Contact Information: Kevin A. Grace, DB Environmental, Inc., 365 Gus Hipp Blvd., Rockledge, FL, 32955, USA, Phone: 321-639-4896, Fax: 321-631-3169, Email: [email protected]


43

Soil Nutrient Dynamics in Coastal Wetlands across a Saltwater-Freshwater Continuum on the Logan River Floodplain, South-East Queensland, Australia Margaret Greenway

School of Environmental Engineering, Griffith University and Cooperative Research Centre for Coastal Zone, Estuary and Waterway Management, Brisbane, Queensland, Australia

The coastal floodplains of the Logan River, south-east Queensland, Australia, support both tidally influenced and freshwater-influenced wetlands, which form a continuum. Mangroves fringe the tidal waterways, with Sporobolus-dominated salt marsh occurring in the supratidal areas. Stands of Casuarina trees occur landward in slightly more elevated and better drained areas. Melaleuca swamp forest occurs furthest landward in flood-prone areas, and in the lowest areas, Phragmites understory dominates. The aim of our study was to assess the soil nutrient status and physico-chemical properties in the salt marsh, Casuarina and Melaleuca wetlands. All wetlands are seasonally inundated, and the salt marsh is tidally inundated. Fluctuations in water depth parallel each other in response to rainfall, indicating connectivity of the water table. At the time of sampling the water table depths were: 83cm-Melaleuca site, 13cm- Melaleuca with Phragmites, 90cm-Casuarina, 50cm salt marsh. Casuarina and Melaleuca occur on sulfuric redox hydrosols that are strongly acidic (3.7 - 4.8) and moderately to highly saline (3-9mS/cm). The salt marsh occurs on extratidal sulfidic hydrosols. The organic A1 horizon ranges from 20-40cm at the Melaleuca site (+2-5cm peat), but where Phragmites occurs, the A1 is deeper (50cm, +5-10cm peat). At the Casuarina site, the A1 is 30cm (+20cm peat), and at the salt marsh site, 30cm (+10cm peat). The uppermost peat layers in the Melaleuca and Casuarina soils had the highest organic content with 24% and 27%TOC respectively. The salt-marsh peat had 16% TOC .The Melaleuca A1 horizons had the highest TC ranging from17% in the top 5 -10cm, to 3% at 30cm, and where Phragmites occurs, from 15% at 5cm to 2.5% at 55cm. At the Casuarina site, TC in the A1 was only 5.5% at 20cm and dropped to 1% at 50cm. In the salt marsh A1, TC was 5% at 10cm and 1% at 40cm. A similar pattern occurred with TN. Melaleuca A1 had the highest TN, 1% in the top 5 -10cm which decreased to 0.2%. Casuarina TN was 0.3% at 20cm and deceased to 0.1%, and in the salt-marsh A1, TN decreased from 0.44% to 0.04%. Below the A1 horizon, there was little change in TC and TN content in any of the wetland soils. Total and available phosphorus displayed some unusual patterns probably reflecting differences in soil pH and geochemistry. As expected NH4-N (KCl extract) was highest in the peaty top 5cm (25mg/kg-Melaleuca; 16mg/kg-Casuarina; 11mg/kg-salt marsh). In the A1, NH4-N decreased to 1mgN/kg in Casuarina soil, and to 2.5mgN/kg in the Melaleuca and salt marsh. Negligible amounts of NO3-N (KCl extract) were found in Melaleuca and salt-marsh soils. In the Casuarina soil NO3-N ranged from 3.3(0-5cm)-0.5(35-40cm)mgN/kg. This may be due to the symbiotic nitrogen-fixing bacteria in the Casuarina roots producing nitrates which then leach into the surrounding soil. Contact Information: Margaret Greenway, School of Environmental Engineering, Griffith University, Brisbane, Queensland 4111, Australia, Phone: +61-7-38757492, Fax: +61-7-38757459, Email: [email protected]


44

Fate of 15N-labeled Ammonium and Nitrate in a Poorly Drained Lolium perenne Field and Herbaceous Riparian Area in Western Oregon

J. H. Davis1, S .M. Griffith1, W. R. Horwath2, J. J. Steiner1 and D. D. Myrold3 1U.S.D.A. Agricultural Research Service, Corvallis, OR 2University of California, Davis, CA 3Oregon State University, Corvallis, OR

Since soil and crop management of Willamette Valley, Oregon, poorly-drained farmland affects water quality, it is important to know the capacity of these wetland landscapes, and their associated riparian zones, to process and retain N. We determined the fate of 15NH4+ and 15NO3

- in an unmanaged herbaceous riparian area and adjacent perennial ryegrass seed field using a pulse-chase experiment. Labeled 15N was applied in spring of 1996 and recovery data were collected 2 and 14 months later. For the first year, recovery of 15NH4+ in the field plant-soil system was 75% and 62% for 15NO3

-, whereas recovery in the riparian zone was only 26% of 15NH4+ and 42% of 15NO3

-. Greater field retention of 15N resulted from both greater uptake of 15N by the crop and greater soil retention of 15N. Low recovery of 15N in the riparian after 2 months was most likely due to prolonged flooding, resulting in lower plant biomass production and N uptake and greater potential loss of N through denitrification, dissimilatory nitrate reduction to NH4

+, and leaching. Surprisingly, the field had similar amounts of total soil N and native labile soil N in the surface soil compared to the riparian. However, subsurface (10-30 cm) total N and native labile N were significantly higher in the field, giving the field overall average higher total N and native labile N than the riparian. One primary difference in N processing between the riparian and field surface soil was in the incorporation of 15N into soil organic matter. More 15N in the total soil N pool and a larger recently incorporated 15N pool in the field implied that the field had larger amounts of N available for mineralization than soil in the riparian zone. In the year the label was applied, plant biomass was the major sink of inorganic 15N in both the riparian and field. In the following year, 4 to 16% of the 15N had moved from the 1996 living plant biomass into the soil organic matter. Although the riparian had less 15N recovery in 1996 plant biomass relative to the field, the riparian was more efficient at sequestering a larger portion of 1996 plant biomass N into soil organic matter in 1997. Relative to the riparian zone, a larger portion of 1996 plant 15N in the field was not incorporated into the soil organic N pool in 1997. This finding correlates well with data from other studies at the site showing greater N mineralization and soil NO3

- accumulation in the field during the warm, dry summer. This is the N component that is vulnerable to loss from the system. Plant uptake was the largest component of N retention in these seasonal wetlands. Consequently, factors such as the degree and longevity of flooding greatly influence the capacity of these systems to retain N not only from the influence on plant biomass production but also by competition for N by reductive microbial processes. Despite the lower overall retention in the riparian zone in both years, the riparian zone retained a larger percent of its N from the first to the second year. This indicates that the N that makes it into the riparian plant biomass is sequestered into soil organic matter to a greater degree than in the ryegrass field. Contact Information: S. Griffith, USDA-ARS, 3450 SW Campus Way, Corvallis, OR 97331, Phone: 541-738-4154, Fax: 541-738-4160, Email: [email protected]


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Geospatial Mapping of Soil Total Phosphorus in the Greater Everglades Ecosystem S. Grunwald1, R. Corstanje1, G. L. Bruland1, T. Z. Osborne1, R. G. Rivero1,2, S. Newman3 and K. R. Reddy1

1 Soil and Water Science Department, University of Florida, Gainesville, FL, USA 2 Department of Urban and Regional Planning, University of Florida, Gainesville, FL, USA

3 South Florida Water Management District, West Palm Beach, FL, USA The Florida Everglades represent one of the largest and most distinct freshwater marshes in North America. Wetland conversion, hydrologic modifications, landscape fragmentation, and nutrient-rich runoff have significantly impacted the ecology of this region. Soil is critical to the functioning of this ecosystem, and its assessment can provide feedback on both the ecosystem status and the effects of management. Overall goal of this project was to improve our understanding of the regional patterns of biogeochemical soil properties, given special attention to soil total phosphorus (TP). Our objective was to characterize the spatial distribution and variability of TP throughout different hydrologic units extending over an area of 8,248 km2. This was the first massive synoptic comprehensive spatial soil mapping event throughout the Everglades ecosystem conducted from April to Dec. 2003. We collected soil samples across the Greater Everglades including Water Conservation Areas (WCA) 1, 2, and 3, Holeyland and Rotenberger, Everglades National Park, Model Land, and Big Cypress at 1,328 sites (+10% replicates) from floc, 0-10 cm and 10-20 cm soil depths. A random-stratified sampling design was used to account for different ecological zones identified using historic soil and vegetative datasets. Soil samples were analyzed by the Wetland Biogeochemistry Laboratory (WBL), UF to characterize a suite of physico-chemical properties including TP. We used geostatistical methods including ordinary kriging and regularized splines to characterize the spatial variability, distribution, and uncertainty of TP predictions. Distinct gradients and spatial patterns of TP were quantified in different hydrologic units caused by external and internal factors (e.g. fires, hurricanes) and naturally and human-induced processes. Interpolations indicated that the areas with the highest levels of TP up to 1,700 mg kg-1 (0-10 cm) were generally located in the eastern section of WCA-2A, parts of WCA-3 near the Miami Canal, and the northern section of Holeyland Wildlife Management Area. Total phosphorus concentrations were lowest in Big Cypress National Preserve (24 mg kg-1; 0-10 cm) and in the southern sections of the Everglades National Park (38 mg kg-1; 0-10 cm depth). The results from this study will provide exciting insights into ecosystem dynamics and guide future management and restoration of this ecosystem. Contact Information: Sabine Grunwald, Soil and Water Science Department, University of Florida, 2169 McCarty Hall, PO Box 110290, Gainesville, FL 32611, Phone: 352-392-1951 ext. 204, Fax: 352-392-3902, Email: [email protected]


46

Fate of Long-lived Artificial Radionuclides in Standing Aquatic Ecosystems of the Chernobyl Exclusion Zone D. Gudkov1, A. Kulachinsky2, A. Nazarov2, L. Zub3, V. Mashina1 and A. Savitsky4

1Institute of Hydrobiology, Kiev, Ukraine 2State Specialised Research Enterprise “Chernobyl Radioecological Centre”, Chernobyl, Ukraine 3Shmalgauzen Institute of Zoology, Kiev, Ukraine 4Kholodny Institute of Botany, Kiev, Ukraine

During 1998-2004 we evaluated the distribution of 90Sr, 137Cs, 238Pu, 239+240Pu and 241Am in the main components of the water reservoirs components within the exclusion zone, defined as a roughly circular area of 30 km radius around the destroyed unit of the Chernobyl NPP. The radionuclide content was measured for bottom sediments, water, seston, 28 species of higher aquatic plant, 6 species of molluscs and 18 species of fish in Azbuchin Lake, Dalekoye-1 Lake, Glubokoye Lake and Yanovsky Creek. The analysis of the radionuclide distribution in components of lakes of the exclusion zone has shown that about 98-99 % of 137Cs and more than 99 % of transuranic elements (238Pu, 239+240Pu and 241Am) of the total radionuclide content concentrated in the bottom sediments. The content of 90Sr in sediments of lakes, due to higher solubility, amount to 89-95 %. About 2-10 % of radinuclides concentrated in water and only about 1 % - in biota. In this percent a prevailing value for different radionuclides has the macrobenthos species (especially bivalvia molluscs) and higher aquatic plants. The part of fish come to 1.5 % of 90Sr, 8 % of 137Cs and practically nothing of transuranic elements concentrated in biotic component. The average specific activity of radionuclides in fish tissue in lakes more than in 100 times exceeds a maximum permissible level for fish production in Ukraine. The numerous effects of irradiation on hydrobionts within the Chernobyl exclusion zone are revealed. Some of these effects required for the short period of time for its formation, however it is supposed that an increasing importance will be got by the remote consequences - genetic damages induced by a long-term irradiation. These remote consequences are long-drawn out in time realisation of changes in molecules of heredity, in which the initial molecular damages can be kept for the long period not being shown and being transferred through many generations of cells. The absorbed dose rate for hydrobionts, living within littoral zone of the researched lakes, due to external irradiation and radionuclides incorporated in tissue was in a range from 0.2 to 3.4 Gy year-1. The highest value was found for hydrobionts from lakes within the embankment territory on the left-bank flood plain of the Pripyat River (Dalekoye-1 Lake and Glubokoye Lake). The molluscs embryos from Dalekoye-1 Lake and Glubokoye Lake were characterised by the maximal rate of chromosome aberration - about 20-25 %, that in 10 times exceeds a spontaneous mutagenesis level for hydrobionts. A little bit less rate is registered for snails from Azbuchin Lake and Yanovsky Creek. The maximal aberration rate in roots of higher aquatic plants (7.8 %) has registered in Glubokoye Lake.

Contact Information: D. Gudkov, Institute of Hydrobiology of the National Academy of Sciences of Ukraine, Geroyev Stalingrada Ave. 12, 04210 Kiev, Ukraine, Phone: +380-44-4189183, Fax: +380-44-4182232, Email: [email protected]


47

Interannual Variability of Two Mexican Tropical Coastal Wetlands

M. F. Gutiérrez, F. Varona-Cordero and G. N. Rivera, Coastal Ecosystems Laboratory. Universidad Autónoma Metropolitana-Iztapalapa, México City, México

Tropical coastal wetlands are subject to drastic changes in conditions, such as large changes in salinity due to infrequent flooding or extreme alterations in freshwater flows which result in significant alterations in productivity and in general environmental conditions. Scarce information is available for tropical wetlands, especially data sets where data quality is known and consistent sampling has been conducted for long periods of time. In this work we present data which fulfill these requirements for two coastal wetlands (Chantuto-Panzacola, Ch-P, and Carretas-Pereyra, C-P) located in the south Pacific coast of México surveyed since 1990 where the same stations have been sampled and the same analytical techniques have been employed. Salinity values confirm the presence of the two main seasons, wet and dry which are a consequence of the changes in freshwater inflow to the system. Within different years changes in salinity reflect changes in freshwater inflow to the systems. Strong episodic flooding events (1998) have deposited great amount of materials and have reduced the average depth from 1.74 to 1.00 m in one lagoon and from 1.23 to 0.64 in the other, leaving during the dry season, great areas of sediments exposed to the atmosphere. Both wetlands have low water transparencies and annual average temperatures above 30 oC. Low oxygen content (< 5.0 ml/l) is characteristic of both systems, especially in Ch-P where annual average values are below 3.0 ml/L. Nutrients show strong seasonal fluctuations as a consequence of changes in freshwater input. During some years, high values of nitrates have been recorded during the wet season, coinciding with high freshwater runoff indicating the influence that the rivers have on the concentration of these elements. Inter-annual comparisons for all the parameters are presented and discussed in order to illustrate the importance and need of long time series for tropical wetlands and in this case for México. Contact Information: F. Gutiérrez M. Laboratorio de Ecosistemas Costeros, Departamento de Hidrobiología. Universidad Autónoma Metropolitana-Iztapalapa. Av. San Rafael Atlixco #86. Col. Vicentina. A.P 55/535. C.P. 09340. México City, México, Phone: 52 55 5804 4737, Email: [email protected]


48

Denitrification Enzyme Activity in Constructed Wetlands and Riparian Zones P. G. Hunt1, T. A. Matheny1, M. E. Poach1 and G. B. Reddy2

1USDA-ARS Coastal Plain Soil, Water, and Plant Research Center, Florence, SC 2North Carolina A&T State University, Greensboro, NC

Effective use of both riparian buffers and constructed wetlands can improve nutrient management in watersheds with significant livestock production. Constructed wetlands with continuous vegetative cover (marsh) have been documented to be very effective for denitrification of nitrogen in swine wastewater. The marsh-pond-marsh wetlands have been shown to be less effective for removal of nitrogen, but they can be somewhat enhanced by soil aeration and the associated nitrification from short interruptions of wastewater application. We used the acetylene blockage method with soil slurries to assess the denitrification enzyme activity (DEA) of both types of constructed wetlands. We specifically investigated changes with additions of carbon and nitrate along with the response of DEA to different wastewater N loading rates. We also similarly assessed DEA in different landscape positions of riparian zones and a watershed impacted by livestock manure application. Rates of DEA in both the riparian zones and the constructed wetlands were consistent with high rates of denitrification. Denitrification appeared to be generally proceeding to di-nitrogen, but some incomplete denitrification (N2O) indicated that more evaluation of this aspect of the denitrification process is needed. Contact Information: Patrick Hunt, USDA-ARS, Soil, Water, Plant Research Center, 2611 W. Lucas St., Florence, SC 29501 USA, Phone: 843-669-5203, Fax: 843-669-6970, Email: [email protected]


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Freshwater and Nutrient Inputs to a Mississippi River Deltaic Estuary with River Re-Introduction Emily C.G. Hyfield1, John W. Day1,2, Jaye E. Cable1,2 and Dubravko Justic1,2

1Coastal Ecology Institute, Louisiana State University, Baton Rouge, LA 2 Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA

In this study, we quantified freshwater and nutrient inputs in the Breton Sound estuary which is receiving freshwater reintroduction in an effort to restore deteriorating wetlands. Almost all wetlands of the Mississippi deltaic plain are isolated from riverine input due to flood control levees along the Mississippi River. This has altered water and nutrient budgets and is a primary cause of the massive wetland loss in the delta. Maintenance of the delta depends on a healthy, functioning ecosystem which includes riverine input. The Breton Sound estuary is located southeast of New Orleans and until recently was hydrologically isolated from direct riverine input. In 1992, a freshwater diversion became operational at Caernarvon, LA that re-introduces freshwater, nutrients, and sediments from the Mississippi River into the estuary. Several inputs and losses were calculated for three annual (2000, 2001, and 2002) water budgets including precipitation (PPN), potential evapotranspiration (PET), the diversion, stormwater pumps, and groundwater. The inputs of ammonium (NH4-N), nitrate (NO3-N), total nitrogen (TN) and total phosphorus (TP) were determined for each of the water sources. There was a different precipitation pattern for each of the years for which water and nutrient budgets were calculated. Precipitation contributed 48-57% of freshwater input while the diversion structure accounted for 33-48%. The net input of fresh groundwater was 3 to 4 orders of magnitude less than diversion input and precipitation. Atmospheric deposition was the largest contributor of NH4-N accounting for 62-72% of the total NH4 input followed by the diversion (total annual NH4-N input was 1.39x105 to 1.96x105 kg). NO3-N input to the estuary was an order of magnitude greater than NH4-N input. The diversion was the greatest source of nitrate to the study area (7.78x105 to 1.64x106 kg) contributing 77-88% of total nitrate input. The diversion contributed 1.26x106 to 2.10x106 kg of TN, representing 77-79% of TN input. The diversion contributed 81-98% of TP input and was an order of magnitude greater than precipitation and stormwater pumps combined. Annual loading rates of NH4-N and NO3-N were 0.16-0.22 and 1.6-2.2 gNm-2y-1, respectively. TN ranged from 1.9-3.2 gNm-2y-1 and TP ranged from 0.17-0.29 gPm-2y-1. Contact Information: Emily Hyfield, Coastal Ecology Institute, Louisiana State University, 2239 Energy, Coast and Environment Building, Baton Rouge, Louisiana 70803, Phone: (225)578-2732, Fax: (225)578-6326, Email: [email protected]


50

Population Genetic Structure of Rhizophora stylosa (Griff.) in Sakishima Islands, Japan Based on Variation at Nuclear and Chloroplast Microsatellite (SSR) Loci Md. Sajedul Islam1, Chunlan Lian2, Norikazu Kameyama3, Bingyun Wu1 and Taizo Hogetsu1

1Graduate School of Agriculture and Life Sciences, the University of Tokyo, Japan 2Asian Natural Environmental Science Center, the University of Tokyo, Japan 3Faculty of Agriculture, University of the Ryukyus, Japan

Mangrove forests are valuable and productive wetlands in world’s tropical and subtropical region. Population genetic information of mangrove species can provide ecological management guidelines to conserve this wetland biodiversity through genetic resources conservation. Rhizophora stylosa is an ecologically important mangrove tree species but no precise information is available regarding its population genetics. Therefore, we studied genetic diversity and population genetics of natural R. stylosa using nuclear and chloroplast SSR markers. Initially six nuclear SSR loci were developed and employed to determine the genetic diversity and population genetic structure of R. stylosa at 19 natural populations on three of the Sakishima Islands, Japan: Iriomote, Ishigaki and Miyako. Our SSR loci showed low polymorphism in R. stylosa populations. The average values of expected (HE) and observed (HO) heterozygosities were 0.261 and 0.132, respectively. All of the six SSR loci were significantly deviated from Hardy-Weinberg Equilibrium in most of the populations (17 populations) and high positive values of FIS (average 0.5413) were also obtained there, which indicate high level of inbreeding. Pairwise FST , which ranged negative 0.015- 0.430 in Iriomote (only two pair produced negative value), 0.026-0.391 in Ishigaki and 0.023-0.572 in Miyako, showed significant genetic differentiation between most of the populations at each of the separate Islands. Generally geographically closer population pairs showed lower and distant pairs showed higher genetic differentiation. At overall populations on each of the three Sakishima Islands, pariwise FST value ranged 0.044 - 0.1484, which also showed pronounced genetic differentiation between the Islands. Furthermore, low average numbers of migrants (Nm) were found within the populations on each of the three separate Sakishima Islands, which were 0.964, 0.982, and 0.599 in Iriomote, Ishigaki and Miyako respectively. Overall Nm value (3.264) was also low within three Saksishama Islands. Low Nm value indicates low gene flow, which may be the cause of significant genetic differentiation between the natural populations of R. stylosa. We also developed three polymorphic cpSSR markers and employed these markers to investigate the maternal lineages i.e. propagule /seed dispersal. We found two haplotypes on all of the three Sakishima Islands. Since all together two haplotypes were found, it can be inferred that pioneer propagules of R. stylosa having each of the haplotypes may be introduced into three Sakishima Islands from two different outside sources. Generally geographically closer population showed similar and distant populations showed different haplotypic distribution, which suggests that propagules of R. stylosa might have been dispersed within rather narrow range. Contact Information: Md. Sajedul Islam, C/O Asian Natural Environmental Science Center, the University of Tokyo, Midori-Cho 1-1-8, Nishitokyo-shi, Tokyo 188-0002, Japan, Phone and FAX: + 81-424-65-5601, Email: [email protected]


51

Comparison of Phosphorus Removal by Two Submerged Plants: The Invasive, Exotic Hydrilla verticillata and the Native Najas guadalupensis Scott D. Jackson, Forrest E. Dierberg, Lisa Canty and Thomas A. DeBusk

DB Environmental, Inc., Rockledge, FL The exotic species, Hydrilla verticillata, frequently dominates the submerged aquatic vegetation (SAV) community in Stormwater Treatment Area (STA) wetlands in south Florida. Hydrilla’s dense canopy and high growth rate, which can provide for a competitive advantage over the native SAV species Najas guadalupensis, may also affect phosphorus (P) removal processes. We compared the water column P removal performance of Hydrilla to Najas in flow-through mesocosms (24-month study) and in an operational STA (4-month study). Mean inflow total P (TP) concentrations (134 µg L-1) were reduced to significantly lower (p<0.05) effluent concentrations (24 µg L-1) in shallow (0.4 m) Najas mesocosms compared to shallow Hydrilla (29 µg L-1) mesocosms. Despite a longer hydraulic retention time (HRT of 10 vs. 4 days), the deep (1 m depth) mesocosms produced higher effluent concentrations than the shallow, but remained consistent with respect to P removal by SAV type with the Najas performing significantly better (p<0.05) (31 µg P L-1) than the Hydrilla (38 µg P L-1). Total P removal for all treatments ranged between 3.52 (deep Hydrilla) and 4.02 g m-2 yr-1 (shallow Najas), or 72 and 82% removal of the inflow P loading, respectively. The effluent from all experimental mesocosms contained soluble reactive P at or near detection limits, while particulate and dissolved P were removed less efficiently. Although there were marked differences in dissolved oxygen concentrations within the mesocosms during diel sampling, P removal performance remained consistent among the treatments throughout the diurnal cycle. Plants in shallow mesocosms had higher tissue P content than those in the deep mesocosms, while standing crop P decreased from inflow to outflow in all treatments and tended to be greater in the Najas mesocosms. In the operational STA, Najas communities exhibited lower water column TP concentrations than Hydrilla communities (31 vs. 46 μg P L-1). The relative difference in the TP removal between the two plant communities implies that prevention and control of Hydrilla in the STAs is desired to attain optimum outflow P concentrations. Contact Information: Scott D. Jackson, 365 Gus Hipp Boulevard, Rockledge, Florida, 32955, USA, Phone: 321-639-4896, Fax: 321-631-3169, Email: [email protected]


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Rejuvenating the Largest Municipal Treatment Wetland in Florida H. Wang1, J.W. Jawitz1, J.R. White2 and M. D. Sees3

1Soil and Water Science Department, University of Florida, Gainesville, FL 2Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA 3City of Orlando, Public Works Department, Bureau of Waste Water, Orlando, FL

The Orlando Easterly Wetland (OEW), the largest constructed wetland for the treatment of wastewater in Florida, was built and came online in 1987 mainly for reducing nutrient loads in tertiary treated domestic waster water produced by the city of Orlando. The OEW is divided into 17 cells arranged into three flow trains, in which the upstream cells were designed primarily for bulk nutrient removal. The wetland has performed better than design expectations, but the phosphorus removal effectiveness experienced some seasonal declines beginning with the winter of 1999. Subsequent studies indicated that the OEW treatment capacity was hindered by inefficient phosphorus removal in the north flow train, which was directly related to hydraulic inefficiency. Therefore, rejuvenating management activities were initiated on the upstream cells of the north flow train in 2002. The management included the removal of plants and organic top sediments, site grading in the interior of the cells, construction of baffles and islands, and re-vegetation. A post-modification tracer test was conducted to evaluate the effectiveness of these activities for the improvement of hydraulic performance. Nutrient removal effectiveness was evaluated based on episodic spatially distributed water samples. The tracer test and water samples showed that both hydraulic efficiencies and phosphorus removal effectiveness of treated cells were significantly increased. However, the wetland has likely re-entered a start-up phase and long-term observation will be necessary to determine eventual steady-state conditions. Contact Information: James W. Jawitz, Soil and Water Science Department, University of Florida, 2169 McCarty Hall, Gainesville, FL 32611 USA, Phone: 352.392.1951 x 203, Fax: 352.392.3902, Email: [email protected]


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Benthic Microbial Mats: Important Sources Of Fixed Nitrogen And Carbon in Mangrove Wetlands. Samantha B. Joye

University of Georgia, Department of Marine Sciences, Athens, GA, USA Microbial mats are a conspicuous, yet understudied and thus poorly understood, component of mangrove wetlands. We collected microbial mats from mangrove habitats in Belize and Panama to determine rates of primary production and nitrogen transformations. The morphology of microbial mats in Belize and Panama was strikingly different, with mats from Belize occurring as thin (< 1 cm) surface films over the soil surface and mats from Panama occurring as thicker (1-3 cm) mushroom-shaped discs that either floated freely or were attached to the soil surface or prop roots. In Belize, a diverse array of cyanobacteria, including filamentous, coccoidal and heterocystous cyanobacteria, as well as purple sulfur bacteria and heterotrophic bacteria, were important components of microbial mat communities. In Panama, the cyanobacterial community was dominated by Lyngbya spp. but a variety of other microorganisms were also present. Purple sulfur bacteria were not a major component of the mat microbial community in Panama. Sediment chlorophyll a concentrations at both sites (up to 900 mg m-2) illustrating high photosynthetic biomass. Rates of primary carbon fixation, measured as gross oxygenic photosynthesis, and nitrogen fixation and denitrification, measured using specific metabolic inhibitors, were determined during day and night incubations. Primary production rates were similarly high across different mat types. Nitrogen fixation rates were substantial under in situ conditions and nighttime activity frequently exceeded daytime activity. In situ denitrification rates were very low in all incubations. In the presence of added nitrate, however, denitrification rates increased significantly during daytime and nighttime incubations such that they equaled or exceeded nitrogen fixation rates. Collectively, the data show that microbial mats are a significant source of fixed carbon and nitrogen in mangroves and suggest that mats may serve as an important component of the food web tropical mangrove wetlands. Contact Information: S. Joye, University of Georgia, Department of Marine Sciences, Room 220 Marine Sciences Building, Athens, GA 30605, USA, Phone: 706-542-5893, Fax: 706-542-5888, Email: [email protected]


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Comparative Assessment of Counter-Measures Efficacy Used in Meadow Cultivation for Transition Reduction of 137CS and 90SR in Grasses of Various Types of Meadows Artur Katushynskiy

Khmelnytskyy Institute of Agroecology and Biotechnology, Khmelnytskyy, Ukraine As a result of the Chernobyl Nuclear Power Station disaster, 6365 km2 of natural and cultured haymaking pasturable wetlands, earlier intensively used for livestock pasture and fattening on the territory of Polisya, Ukraine, was contaminated. It has been studied vertical migration and behaviour of 137Cs and 90Sr in soil on main types of meadows (dry lands, flood-lands, swamped lands) in Narodychy and Korosten area of Zhytomir region, Dybrovitsa area of Rivne region and Kamin-Kashyrskyy area of Volyn region within a period of 1998 - 2004. It has also been learnt the above radionuclides transition into meadow vegetation taking into consideration specific plant features. The aim of the study was to conduct migration analysis of the above said radionuclides and to assess the efficacy of various counter-measures which reduces accummulation of radionuclides in perennial sowing grasses. Research results have shown that most effective counter-measures, reducing radionuclides transition in grass of various meadows types are root improvement. The most important of its component has to be obligatory application of heightened dose of phosphorous, potassium fertilizers and dolomite flour. This technique with further annual fertilizer insertion under each after-grass allows to obtain feed with radionuclides content of 3 to 15 times lower than in natural grasses within a period of 5 years after root improvement of contaminated meadows. It has been revealed that amount reduction of 137Cs accumulation reaches 4-10 times for sowing plants of waterlogged meadow, 3-4 times for the sowing plants of dry meadows and more than 10 times for the sowing plants of flood-lands. It has also been shown that counter-measures efficacy of 90Sr on the studied meadows types is considerably lower comparatively with 137Cs. Amount reduction of 90Sr accummulation in the sowing plants under root improvement do not exceed 2.0 - 2.6 times. It has been revealed that less effective method of radionuclides transition reduction is surface insertion of mineral fertilizers and dolomite flour on the natural grass without creating cultural grass. It has been shown that amount reduction divisibility of receipt of 137Cs was low. It has concluded 1,1 times on dry and water-meadow meadows and 1,9 times on waterlogged meadows. As regards 90Sr positive result has not been observed on any studied types of meadows. It has been shown that counter-measures influence is effective enough but their duration of the effect is limited by land types, pollution density, time passed after overgrowing. It has been determined that with the course of time it is observed increase in quantity of radionuclides transition in plants as a result of grass degradation. In such case it is nececssary to conduct recurring overgrowing to allow get corresponding pure production in the first year of grass life. Study results have shown that both overgrowing and inter-overgrowing assist radionuclides receipt reduction in perennial cereal grass harvest of the main types of meadows exposed to radioactive pollution. Counter-measures complex applicaion allows to get feed with radionuclide content not exceeding Ukrainian norms. Contact Information: ArturKatushynskiy, Khmelnytskyy Institute of Agroecology and Biotechnology, Environmental Biology Department, 40/1 Shestakova Street, Khmelnytskyy, 29000 UKRAINE, Phone: 380 382 788142, Fax: 380 382 788142, Email: [email protected]


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Vegetation and Sediment Gradients in Wetland Mesocosms Used for Low-Level Phosphorus Removal Michelle Kharbanda, Thomas A. DeBusk, Forrest E. Dierberg and Scott D. Jackson

DB Environmental, Inc., Rockledge, FL Six large treatment wetlands, designated Stormwater Treatment Areas (STAs), have been constructed to reduce phosphorus (P) loading into the Everglades. While these STAs have been successful at meeting interim water quality goals of 50 µg TP/L, research is continuing to further optimize the STAs in order to achieve lower outflow concentrations. One recent finding is that STA performance can be enhanced by culturing submerged aquatic vegetation (SAV) in the wetland outflow region. We performed a long-term mesocosm study using SAV to better characterize low-level P removal capabilities of the STAs. Duplicate treatment trains, each consisting of three mesocosms in series, were constructed and monitored for 5.5 years. These 0.4 m deep mesocosms contained a muck substrate and were initially stocked with the SAV species Chara zeylanica, Ceratophyllum demersum, and Najas guadalupensis. Each treatment train received low nutrient (average 31 µg TP/L) agricultural waters that had been previously treated by an STA. Over the period of record, the mesocosms were operated under varying P loading conditions (ranging from 0.6 to 1.9 g P/m2/yr), mimicking the phosphorus load that an STA would expect to receive. Within the first year, all mesocosms became dominated by Chara zeylanica. The mesocosms consistently removed TP during the study, reducing average inflow concentrations from 31 to 15 µg TP/L. Outflow TP levels did not vary substantially with changes in inflow TP loads. Inflow soluble reactive P was removed in the mesocosms to the analytical detection limit, and dissolved organic P and particulate P were reduced by 42 and 69%, respectively. Even though the SAV systems received low nutrient inflow waters, a marked gradient in standing crop biomass P and sediment P accretion was observed within the mesocosm treatment train. After 5 years of operation, the Chara tissue P concentrations were 939, 349 and 144 mg/kg, and overall tissue P storage was 2.60, 0.75 and 0.18 g P/m2 for the first, second and third mesocosms in series, respectively. For these same mesocosms, respective sediment accretion rates averaged 2.45, 1.91 and 0.91 cm/yr. Because sediments are the ultimate reservoir of P removed in a treatment wetland, this long-term study has provided useful insight into the performance and sustainability of SAV-dominated treatment wetlands receiving low nutrient waters. Contact Information: Michelle Kharbanda, 365 Gus Hipp Boulevard, Rockledge, Florida, 32955, USA, Phone: 321-639-4896, Fax: 321-631-3169, Email: [email protected]


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Activity and Controls of Methanogenesis in Catotelm of Acid Peatlands from Central Russia I. Kravchenko1 and A. Sirin 2

1Winogradsky Institute of Microbiology RAS, Moscow, Russia 2Institute of Forest Science RAS, Moscow Region, Russia

Northern peatlands are unique ecological communities with permanently waterlogged peat substrate and an important component of the terrestrial carbon budget and storage. Carbon dynamics in peatlands influences atmospheric CO2 and CH4 concentrations and thus future changes in this carbon storage have the potential to influence greenhouse gas-induced warming. In Russia about 20% of territory is covered by peatlands. These represent at least 30% of the global peat carbon and more then 80% appears in deep (>0.5 m) peat layers. Traditionally methane stored in the deep peats, in so-called inert zone (catotelm) is considered to be relatively immobile. Recent studies revealed significant temporal changes of methane concentrations in deep peat layers, and its variations suggest production and removal of methane. To test this hypothesis we have analysed the main processes of methane formation and chemical factors affecting the activity of methanogens within the vertical profile of three permanent typical boreal mires in the central part of European Russia (Zapadnaya Dvina Experimental Station, Institute of Forest Science RAS). There are two “ombrogenous” mires - Petrilovo raised bog (on clay, 10 m depth) and Sosviatskoje (on sands, 5 m depth), and one “topogenous” mire - Zailovije fen (with groundwater upwelling, 4 m depth). The rates of methane production were evaluated in anoxic microcosms at in situ pH. Supplemental H2-CO2 stimulated the linear production of CH4 in all samples, and stoichiometry was about 3 mol of H2 and 1 mol CO2 consumed per 1 mol CH4 formed indicating the hydrogenotrophic methanogenesis. The rates of methane production in Zailovije fen were 3-6 ng CH4 g -1 h-1 within all peat profile. In raised Petrilovo and Sosviatskoje bogs the CH4 production rates were about 5 ng CH4 g -1 h-1 in upper 0 - 1.5 m, and increased greatly up to 15-30 ng CH4 g -1 h-1 in deep layers. The formation of CH4 is largely determined by microbiological transformations of organic matter; so, the physical and chemical availability of carbon sources and electron acceptors is crucial. The addition of protonated volatile fatty acids (acetate, propionate, butyrate and formate) and SO4

2- and NO3- has

inhibited the methane production. The high content (2-15 mg l-1) of these acids were estimated in peat profile. The comparison of position of local maximums of methanogenesis and fatty acids content in peatlands profiles, and seasonal dynamics of fatty acids concentrations indicated that the sources for methane formation in catotelm are the organic compounds produced by living plants and entered from upper layers by intensive mass exchange. An MPN of 107 cells g-1 was obtained for hydrogenotrophic methanogens in all mires and their distribution in profiles were monotonous. These results indicated that in catotelm the anew CH4 is formed microbiologically. H2 was found to be an important substrate for methanogens, therefore interspecies hydrogen transfer associated with organic carbon degradation is very important. The accumulation of fatty acids inhibited methanogenesis and may be the metabolic control of methane production and accumulation. The investigation was supported by the RFBR (grants 01-05-64792 and 04-05-64861) Contact Information: I. Kravchenko, Winogradsky Institute of Microbiology RAS, Prospect 60-let Octyabrya, 7/2, 117312 Moscow, Russia, Phone: +7-095-1357924, Fax: +7-095-1356530, Email: [email protected]


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Microbial Factors Affecting Transformation of CH4 and N2O in Rice Soils from Different Regions I. Kravchenko1 and K.Yu 2

1Winogradsky Institute of Microbiology RAS, Moscow, Russia 2Wetland Biogeochemistry Institute, LSU, Baton Rouge, USA

Rice paddies are responsible for production of two important greenhouse gases, CH4 and N2O, emitted mostly from soil biotic sources. Methane is produced in anaerobic environment by obligate anaerobic microorganisms (methanogenesis) and is oxidized at anaerobic-aerobic interface (methanotrophy). Most of the N2O - is produced from denitrification under anaerobic conditions, although nitrification under aerobic conditions is also a contributor. Recently eight rice soils from the 5 major rice-cultivating states in the US (Arkansas, California, Louisiana, Mississippi, and Texas) and from 3 international regions (China, Indonesia, Thailand) were studied using a microcosm technique. It was found that each soil exhibited a unique signature of developing an optimum redox window with a minimum accumulation of greenhouse gases. The objective of this study was to evaluate the population density of microorganisms responsible for the transformation of CH4 and N2O (methanogens, methanotrophs, denitrifiers, nitrifiers) in an effort to explain these differences. The soil slurry (1:4, w:v) was prepared for each soil, amended by straw and KNO3 and incubated for about 2 months. The most probable number (MPN) technique was applied to enumerate the cultured bacteria (methanotrophs, ammonium- and nitrite-oxidizing nitrifying and denitrifying bacteria) and archea (acetate-utilizing and H2-CO2-utilizing methanogens) . An analysis of methanogens indicated that acetate-utilizing methanogens (107 cells g-1) outnumbers H2-CO2-utilizing methanogens by over 4 orders magnitude in all US soils and by almost 2 orders of magnitude in China soil. In Indonesia and Thailand soils MPN values of both methanogens were about 104-105 cells g-1. The high number of methanotrophic bacteria (105-106 cells g-1) was evaluated in all soils with the exception of Thailand and Arkansas (103 cells g-1). The members of type II methanotrophs belonging to Methylosinus and Methylocystis genera were detected in the highest positive dilution steps by serological analysis, and were proposed to be the dominants in the CH4-oxidizing communities of rice soils. Denitrifying and nitrifying bacteria were significantly higher in Arkansas and Texas soils (106 cells g-1) than in all other soils (103-104 cells g-1). At present, it is not apparent to what extent the population density of microorganisms under investigation affects the production and consumption of CH4 and N2O. However, the differences described here provide a basis for future studies linking population density and structure and in situ rates of microbial activities to key edaphic parameters and will provide a context for understanding the relationship between microbial diversity, biogeochemical cycles and Global Change. The investigation was supported by the NATO Collaborative Linkage Grant EST-CLG-979858 Contact Information: I. Kravchenko, Winogradsky Institute of Microbiology RAS, Prospect 60-let Octyabrya, 7/2, 117312 Moscow, Russia, Phone: +7-095-1357924, Fax: +7-095-1356530, Email: [email protected]


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The Effect of the Caernarvon Freshwater Diversion on Water Quality in the Breton Sound Estuary Robert R. Lane1, John W. Day1,2, Emily Hyfield1,2 and Jason N. Day1

1Coastal Ecology Institute, Louisiana State University, Baton Rouge, LA 2Department of Oceanography and Coastal Science, Louisiana State University, Baton Rouge, LA

Water quality transects were carried out in the major waterways of the Breton Sound estuary starting in September 2000 and continuing through August 2002. Twenty discrete water samples were taken in the basin for nutrient analysis, and turbidity, salinity, temperature and fluorescence were measured continuously with a flow-through system. Nitrate concentrations were as high as 80 umol/L-NOx near the diversion and decreased with distance from the structure. The same trend was observed for TN, with concentrations ranging from 100-280 umol/L near the diversion, and decreasing with distance from the structure. Phosphate concentrations were typically >1.5umol/l-PO4 during the late spring- early summer and lower during late winter-early spring. Total Phosphorus concentrations were temporally variable within the estuary, with higher concentrations during the summer months (>3 umol/l), and lower values during the winter months (<2 umol/l). Silicate concentration were higher in the upper and lower basin during the summer (>110umol/l), and lower concentrations were observed during winter-early spring (<45umol/l). Discharge through the Caernarvon structure had an overwhelming effect on salinity throughout the Breton Sound estuary, even at moderate to low discharge. Total suspended sediment generally decreased with distance from the diversion structure, but there was also widely fluctuating TSS levels at outer reaches of the estuary associated with storm events. Chlorophyll a generally peaked during the summer in the mid-estuary, and was inversely correlated to discharge. These results suggest river diversions may be used to process Mississippi River water prior to reaching offshore waters where eutrophication has become a recent concern, as well as enhancing marsh formation and stability, and preventing salt water intrusion from degrading Louisiana's remaining coastal wetlands. Contact Information: Robert R. Lane, LSU- Coastal Ecology Institute, Energy Coast & Environment Building, Baton Rouge, Louisiana 70802, Phone: 225-578-6092, Fax: 225-578-6326, Email: [email protected]


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Primary Production and Respiration Rates of Microbial Mats in an Oceanic Mangrove Ecosystem Rosalynn Y. Lee, Samantha B. Joye and Christof Meile

University of Georgia, Department of Marine Sciences, Athens, GA, USA Microbial mats are dynamic contributors to ecosystem primary production and elemental cycling. We investigated microbial mat carbon (C) and oxygen (O) cycling in mangrove soils on Twin Cays, a pair of tropical oceanic mangrove islands in the oligotrophic waters offshore of Belize. Twin Cays mangroves grow along a tree-height gradient, with the tallest trees on the ocean-fringing edge of the islands. Tree height decreases through a transition ecotone of intermediate-height stands towards the center of the islands, where dwarf-height trees proliferate around treeless ponds and lagoons. The tree-height gradient provides a natural environment in which to study the relationship between soil light availability and benthic primary production. Filamentous and heterocystous cyanobacteria, purple sulfur bacteria, diatoms and algae coat the soil surface and dominate photosynthesis in microbial mats. Chlorophyll a concentrations were highest in the dwarf, intermediate in the fringe and lowest in the transition ecotone, but exhibited large within-site variability. Detailed HPLC pigment analysis revealed that transition and fringe sediments were dominated by diatoms and anoxygenic photosynthetic bacteria, with minimal cyanobacterial presence. Dwarf sediments, however, were dominated by cyanobacterial pigments, though diatoms and anoxygenic photosynthetic bacteria were also present (up to 30.9 mg fucoxanthin m-2 and 102.6 mg bacteriochlorophyll a m-2, compared to a maximum chlorophyll a of 993 mg m-2). Diel rates of O and C cycling were examined using microelectrodes and isotope tracer techniques. Primary production rates were high, up to 4.2 mmol C m-2 h-1 (net) and 45 mmol O2 m-2 h-1 (gross) under full daylight illumination, and variable across different mat types. Inorganic carbon in Twin Cays’ microbial mats is fixed primarily by phototrophs, 75% of which employ oxygenic photosynthesis, while a small, but significant percentage (12%) of CO2 is fixed by chemolithotrophs. Maximum rates of gross oxygenic photosynthesis (GOP) averaged across all sites were about 18 mmol O2 m-2 h-1 independent of season. Half-saturation of GOP occurs at PAR of <200 µE m-2 s-1, illustrating the ability of microbial mat organisms to fix C efficiently at lower light levels. Oxygen profiles were examined using an inverse model to quantify respiration and net O2 production/consumption rates. Over a diel cycle, all tree-height ecotone mats were net autotrophic, and net rates of O2 production correlated with chlorophyll concentration. The model results indicate that respiration rates were proportional to GOP during the day, and their relative magnitude at night also followed the spatial pattern observed in GOP between the three ecotones. Comparisons of C and O processing in fringe, transition and dwarf ecotones show that dwarf mangroves support the highest rates of carbon fixation. In the Twin Cays system, microbial mats account for a significant amount of primary production and dwarf mats, especially, may serve as an important component of the food web. Contact Information: Rosalynn Lee, University of Georgia, Department of Marine Sciences, Room 208 Marine Sciences Building, Athens, GA 30605, USA, Phone: 706-542-6818, Fax: 706-542-5888, Email: [email protected]


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Assessing Trace Metal Accumulation in a Constructed Wetland Receiving Domestic Wastewater Els Lesage1, D.P.L. Rousseau2, F.M.G. Tack1, M.G. Verloo1 and N. De Pauw2

1Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent, Belgium 2Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent, Belgium

Although concentration levels of trace metals generally do not constitute a major problem in domestic wastewater, their accumulation in constructed treatment wetlands over time may be of concern. At this time it is difficult to estimate how long a constructed wetland can work efficiently before the wetland itself becomes a “black point”. The purpose of this study was to evaluate the accumulation of trace metals in sediment and Phragmites australis biomass of a horizontal subsurface flow wetland treating domestic wastewater after 3 years of operation. Influent and effluent wastewater was sampled regularly and analysed for trace metals. The mass of trace metals removed from the wastewater after 3 years of operation was estimated by taking into account flow data. Samples of the gravel filter medium were taken at 4 distances from the inlet (1, 5, 25 and 50 m) at 3 points along the width of the bed. Roots were removed from the gravel samples and rinsed with deionized water. Sediment was removed from the gravel samples by a combination of rinsing and sonication in deionized water. Trace metals associated with the sediment were analysed after digestion of the rinsing suspension with HNO3 and H2O2. P. australis biomass was sampled at the same sampling points and analysed for trace metals in leaves, stems, and panicles. Metal concentrations in roots were generally higher than in aboveground P. australis biomass. A decrease in trace metal concentrations in the roots was noted with increasing distance from the inlet, except for Mn where root concentrations showed an increase. Trace metal concentrations in aboveground P. australis biomass did not significantly change along the longitudinal profile of the bed, except for Mn where significantly higher concentrations in leaves, stems, and panicles were observed from 25 m onward. Cu, Zn, Cd, and Pb concentrations associated with the sediment decreased exponentially along the longitudinal profile, with a sharp decrease within the first 5 m of the reed bed. Trace metal concentrations in the sediment of the inlet area were elevated, i.e. at 1159 ± 381 mg kg-1 for Zn and 322 ± 56 mg kg-1 for Cu. Cr, Ni, Al, and Fe concentrations in the sediment also demonstrated a decrease with increasing distance from the inlet, but the decrease did not follow an exponential trend and was smaller than for Cu, Zn, Cd, and Pb. Mn concentrations in the sediment showed an increase along the longitudinal profile. The estimated mass of trace metals accumulated in the sediment of the wetland agreed in order of magnitude with the estimated mass of trace metals removed from the wastewater during an operational period of 3 years. The importance of sufficient monitoring of trace metals in influent and effluent wastewater combined with flow measurements is emphasized. Contact Information: E. Lesage, Laboratory of Analytical Chemistry and Applied Ecochemistry, Department of Applied Analytical and Physical Chemistry, Coupure Links 653, Ghent, 9000, Belgium, Phone: +32 9 264 60 94, Fax: + 32 264 62 32, Email: [email protected]


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Pilot-scale Horizontal Subsurface Flow Treatment Wetlands for Model Calibration Purposes Els Lesage1, D.P.L. Rousseau2, A. Story2, N. De Pauw2, P.A. Vanrolleghem3, F.M.G. Tack1 and M.G. Verloo1

1Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent, Belgium 2Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent, Belgium 3BIOMATH, Ghent, Belgium

Decades of research on constructed treatment wetlands have revealed the need for better insight in internal processes and for more adequate design tools. State-of-the-art model-based design of treatment wetlands is still limited to first-order models that assume an exponential decrease of pollutant concentrations to a background value. However, this black-box model is based on only two parameters, the first-order decay rate k and the background concentration C*, which is an obvious oversimplification of the complex wetland processes. Current research is therefore increasingly oriented towards dynamic, mechanistic modelling. These models usually require specific datasets for calibration and validation purposes. This study intends to collect such specialised data by means of two pilot-scale wetlands with a high level of controllability. Two replicate pilot-scale horizontal subsurface flow wetlands were constructed in a greenhouse in December 2004. Pilot-scale wetlands are 2.5 m long, 0.60 m wide, and filled with gravel (Ø 3-8 mm) to a depth of 0.45 m. An inlet and outlet area of 0.20 m long, filled with gravel (Ø 8-16 mm), was created in order to obtain optimum flow distribution. Each wetland was planted with 32 Phragmites australis plants. A light regime of 16 h is being maintained. Concentrated synthetic wastewater stored at pH 3 is mixed with tap water and the diluted wastewater is alternately fed to the wetlands. Effluent is evacuated by means of a transverse perforated pipe at the bottom of each wetland. The water level is adjustable by means of a flexible tube. Regular analysis of concentrations of a range of pollutants (organic loading, nutrients, and trace metals) in influent and effluent is performed. Influent and effluent flow rates are monitored in order to obtain water and mass balances. Sampling ports were installed along the length of both wetlands (at 0.25, 0.5, 1 and 2 m from the inlet) and at 3 different depths (0.1, 0.2 and 0.4 m from the gravel surface). Regular analysis of pollutants in the sampling ports along the length of the wetland will allow calibration of theoretical removal models. A lithium tracer study is currently being performed to gain insight in hydraulic characteristics of the pilot-scale wetlands. The poster will show results of the LiCl tracer study, ammonium and phosphorus sorption characteristics of the gravel, removal efficiencies of COD, N, P, and trace metals during the start-up phase of the wetlands, and transect data of these pollutants along the wetlands. Contact Information: E. Lesage, Laboratory of Analytical Chemistry and Applied Ecochemistry, Department of Applied Analytical and Physical Chemistry, Coupure Links 653, Ghent, 9000, Belgium, Phone: +32 9 264 60 94, Fax: + 32 264 62 32, Email: [email protected]


62

Gas Exchange Responses of Black Willow (Salix nigra) Cuttings to a Range of Soil Moisture Regimes S. Li1, S. R. Pezeshki1, S. Goodwin2 and F. D. Shields, Jr.3

1Department of Biology, The University of Memphis, Memphis, TN, USA 2W. Harry Feinstone Center for Genomic Research, The University of Memphis, Memphis, TN, USA 3USDA-ARS National Sedimentation Laboratory, Oxford, MS, USA

Black willow (Salix nigra) is used extensively for riverbank erosion control and riparian zone restoration. However, many projects in southeastern United States have reported low survival rates. Previous studies indicate that extreme soil moisture conditions (flooding, drought) are among factors responsible for such poor performance. However, the mechanisms underlying the low survival are less clear. This study was conducted to quantify gas exchange and biomass partitioning responses of black willow to a range of soil moisture regime. Under greenhouse conditions, potted cuttings were subjected to four levels of soil moisture conditions: well-watered (control), continuous flooding, periodic flooding and periodic drought. The results demonstrated that stomatal limitation was one of the factors that led to the reduced photosynthetic capacity in continuously flooded cuttings. Under periodic drought conditions, stomatal closure, decreased leaf chlorophyll content and increased dark fluorescence yield contributed to photosynthetic decline. Continuously flooded cuttings accumulated the lowest shoot biomass while the final height and root growth were most adversely affected by periodic drought. Periodically flooded cuttings tended to allocate more photoassimilate to root growth than to shoots. Our results provided evidence that: 1) photosynthesis and growth in black willow were limited by stomatal closure under continuous flooding and periodic drought. Non-stomatal factors also were involved in such responses under periodic drought conditions; and 2) soil moisture plays an important role in governing success of transplanted black willow cuttings thus, it is critical to take soil moisture conditions into consideration for restoration planning. Contact Information: S. Li, Department of Biology, The University of Memphis, Memphis, TN 38152, USA, Phone: 1-901-678-3038, Fax: 1-901-678-4746, Email: [email protected]


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Nutrient Cycling in a South Carolina Tidal Salt Marsh Christel J. Lopez, Emily N. Sekula, Lauren C. Kolowith, Liza M. Johnson and Timothy J. Callahan

Department of Geology and Environmental Geosciences, College of Charleston, Charleston, SC Tidal salt marshes are highly productive systems that dominate the coastline of the southeastern United States. The major factors that influence salt marsh biogeochemistry are groundwater input, nutrient import and export via tidal creeks, and the seasonal cycles of vegetation (such as smooth cordgrass, Spartina alterniflora). In this study, the freshwater influence on marsh nutrient cycling was examined through a compilation of two years of seasonal data collection at a relatively undisturbed tidal salt marsh 17 miles south of Charleston, SC. Porewater diffusion cores were emplaced along two transects from the major tidal source towards the inland maritime forests to assess the freshwater/saltwater influence on nutrient dynamics. Ammonium, phosphate, sulfate, and iron were analyzed spectrophotometrically. In addition, freshwater samples from water table wells in the adjacent upland area were analyzed for ammonium, nitrate, iron, and phosphate. Preliminary data suggest that the tidal influence on the surficial aquifer is small, and efforts are ongoing to quantify the volume of fresh groundwater discharging into the salt marsh. Nutrient analyses revealed that variation with depth in the salt marsh appears to be predominantly regulated by the uptake by vegetation and reducing conditions. Nutrient spatial variability appears to be largely due to the topography (high marsh versus low marsh), present vegetation (barren versus Spartina alterniflora), and time of inundation (tidal flat versus tributary channel). Contact Information: Timothy Callahan, Department of Geology and Environmental Geosciences, College of Charleston, 66 George Street, Charleston, SC 29424, Phone: 843-953-5589, Fax: 843-953-5446, Email: [email protected]


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Seasonal Dynamics Assessment of Greenhouse Gases Emission in Peat Soils of Flood-Lands of River Stokhid Vitaliy Luchka

Khmelnytskyy Institute of Agroecology and Biotechnology, Khmelnytskyy, Ukraine At present world peat reserves are estimated in 500 billion tonnes and are considered as unique natural reservoir of organic substance, defining in many respects global balance of greenhouse gases (mainly СО2 and СН4) in contemporary atmosphere of the Earth. The largest marsh area in Ukraine (over 85% of all peat resources) is concentrated in forest swampy zone of Polissya of Ukraine. Centre of the research of the meliorated peats has become flood-land of river Stokhid which is water intake of drainage systems “Upper reaches of river Stokhid” and Dukhche-Perespynska. River Stokhid, being inflow of river Pryp’yat, belongs to Dniper’ basin. It originates from Volynskyy height of Lokachiv area of Volyn region and flows in Volyn region from south-west to the north-east falling in river Pryp’yat within Lyubeshiv area of the Volyn region. To the north-west of village Perespa, where the hydrology post is located on the river Stokhid, river valley is slightly widened and its width reaches 6-7 km. This spacious lake-looking expansion is laid by peat. This is the place where studied peat soils are located. Drainage system construction causes fundamental changes in swampy landscapes. Peat drainage reduces weighing pressure of swampy waters on upper stratum of peat bed, peat shrinking occurs, the aerobic processes of its decomposition intensify, conditions for accelerated mineralisation of peat soils organic substance are sprung up, greenhouse gases (СО2, СН4 and N2O) emission from soil to the atmosphere increases. The aim of present research was to define influence of long development on carbon and nitrogen microbial transformation processes in peat soils of flood-lands of river Stokhid. СО2 emission intensity was being defined by emissive chambers method which foresees speed measurement of СО2 accumulation within insulator fit in the soil in a depth of 0,05 - 0,1 meter. Denitrification activity and methane emission were being determined by the same method. But immediately after insulator installation acetylene was injected (10% of chamber capacity) through rubber plug into its inner volume which blocks denitrification process in the stage of nitrous oxide (N2O) formation. Intensity of greenhouse gases isolation was being determined during vegetation periods of 2002 and 2003. For this purpose four plots for conducting researches were selected. First plot differs from the others by a long history of development - more than 50 years.The plots 2 and 3 have been used for cultivated crops planting for more than ten years. Development age of the above soils are thirty years. Plot 4 was selected as a control one in view of the fact that this land has never undergone any agricultural cultivation and natural vegetation has been preserved in this place. On the basis of the biennial observations of seasonal dynamics of peat soils biological activity it has been ascertained that peat soils, being on the first stage of development, are distinguished by high emission of greenhouse gases. On the contrary, perennial agricultural use of peat leads to reduction of greenhouse gases emission. Estimation of dynamics of isolation and absorption processes of greenhouse gases has shown that such correlation between studied peat soils is beign kept during the whole vegetation period. It has been determined that highest possible activity of the isolation and absorption processes of greenhouse gases among all the studied peat soils is observed at the second half of the summer - at the hottest and driest time of the year. Contact Information: Vitaliy Luchka, Khmelnytskyy Institute of Agroecology and Biotechnology, Department of Agricultural Chemistry, 40/1 Shestakova Street, Khmelnytskyy 29000 Ukraine, Email: [email protected]


65

Seasonal and Geomorphological Variability of the Quantity and Quality of Dissolved Organic Matter (DOM) in the Florida Coastal Everglades Nagamitsu Maie, Kathleen Parish and Rudolf Jaffé

Department of Chemistry & Biochemistry, and Southeast Environmental Research Center, Florida International University, Miami, FL USA

Since dissolved organic matter (DOM) can control sunlight penetration, transport and cycling of N, P and metal species, and fuels the microbial loop, the understanding of dynamics of DOM is a key issue to understand the biogeochemical process in the Everglades ecosystem. With that goal in mind, we collected monthly water samples for 2 years along Shark River Slough (SRS) and Taylor Slough (TS) and throughout Florida Bay (FB) at sites that are identical with those of the FCE-LTER (http://fcelter.fiu.edu/). Water samples were filtered (0.22 µm) and the quantity and quality of DOM were investigated by determining DOC concentration, optical properties such as UV absorbance at 254nm and fluorescence emission spectra at excitations of 313nm and 370 nm. Furthermore, total hydrolysable carbohydrate and total protein concentrations were analyzed colorimetrically. DOM was also fractionated using insoluble Polyvinylpyrrolidone (PVP) into adsorbable (humic) and non-adsorpbable (non-humic) fractions. Averages of DOC concentration (mgC L-1) was 14 ± 5, 10 ± 3, and 6 ± 3, for SRS, TS, and FB, respectively. PVP-adsorbed fraction composed of its 26 ± 6%, 22 ± 9%, and 6 ± 5%, respectively. Carbohydrates were found to be a significant component of DOM in both of the freshwater (~20%) and FB (~15%) sites. It was shown that the quantity and quality of DOM varied depending on soil types, vegetation, and seasonality (water regime). As such the % carbohydrates was usually higher throughout the wet season while % proteins showed a peak at the very beginning of the rainy season. With the exception of the FB sites, optical properties show that microbial contribution to the DOM pool was more important during the dry season. The major portion of DOM in FB is considered to be autochthonous and the influence of land derived DOM seems minor. Contact Information: Nagamitsu Maie, Florida International University, Southeast Environmental Research Center, OE-148, University Park, Miami, FL. 33199, USA, Phone: +1-305-348-6085, Fax: +1-305-348-1667, Email: [email protected]


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Phosphorous Sequestration Using Al-containing Amendments in Organic Soils from a Municipal Wastewater Treatment Wetland John R. White1 and Lynette M. Malecki2

1Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, USA

2Wetlands Biogeochemistry Laboratory, Soil and Water Science Department, University of Florida, Gainesville, FL, USA

Constructed wastewater treatment wetlands are a relatively low-cost alternative increasingly being used in developing countries to provide primary wastewater treatment, while in industrial nations of Europe and North America, treatment wetlands are being used for tertiary treatment of nutrients prior to discharge into surface waters. Over time, the phosphorus (P) removal capacity of these constructed treatment wetlands may decline. The Orlando Easterly Wetland (OEW) Reclamation Project is one of the oldest and largest constructed treatment wetlands in the United States, located east of Orlando in Christmas, FL. The OEW has consistently reduced nutrient concentrations to meet discharge permit requirements. Recently, P concentrations have increased during the winter months resulting in concern over the P binding capacity of the soil. Little research has been done on methods to restore the treatment capacity of older constructed wetlands since most of the treatment wetlands in use today are relatively young. One method to increase the P binding capacity of the wetland soils is to add amendments containing Al. An intact core incubation study was performed to determine the effectiveness and dosages of alum and three other Al-containing alternatives (alum residual, polyaluminum chloride (PAC), and partially-neutralized aluminum chloride (PNAS)) in immobilizing P in organic soils under anaerobic conditions. Seventy-eight cores were collected; six replicates for each of the four chemical amendments, three dosage rates, and six controls. The dosages were 35.97 g Al m-2, 17.99 g Al m-2, and 8.99 g Al m-2 for each amendment. The pH, dissolved reactive P (DRP), and soluble Al were measured over a two-week time period in the water column. Overall, the water column pH of the cores treated with alum were significantly lower than all other treatments averaging 3.65 ± 1.12, while the cores treated with PAC (4.85 ± 0.96) and PNAS (4.21 ± 0.93) had pH values significantly lower than the alum residual and controls averaging 6.12 ± 0.19 and 6.09 ± 0.25, respectively. For all treatments, the cores receiving the highest dosage had significantly lower water column pH values than the mid and low-level dosages. The DRP uptake rates of all treatments (-60.41 mg m-2 d-1 to -2.11 mg m-2 d-1) were significantly less than the release rates of the controls (averaging 2.27 mg m-2 d-1). There were no significant differences in P flux rates between dosage levels for any of the treatments, however, at all dosage rates the alum, PAC, and PNAS were more effective at binding P than the alum residual. This research suggests that a one-time application of an Al-containing chemical amendment might prevent release of P from the soil back into the water column, however long term studies are needed to verify efficacy over time. Contact Information: Dr. John R. White, Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, Phone: 225-578-8792, Fax: 225-578-6423, Email: [email protected]


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Contribution of Benthic Mats to Vertical Accretion and Deposition of C and N in Caribbean Mangrove Forests Karen L. McKee1 and Samantha B. Joye2

1National Wetlands Research Center-USGS, Lafayette, LA, USA 2University of Georgia, Athens, GA, USA

Benthic mats composed of filamentous algae, roots of emergent plants, microbial communities, or a combination of these may form on the soil surface of coastal wetlands. Despite their potential importance to vertical accretion, few data exist on the contributions of benthic mats to soil development. Although mat formation may be limited in areas of high sediment input, this process is common in mangrove forests growing in sediment-deficient areas, e.g., the Caribbean Region. Benthic mats were consequently studied in Belize and Panama where organic (peat) soils predominate and surface elevations are maintained primarily through biogenic processes of production and decomposition. Benthic chlorophyll concentrations ranged between 50 and 950 mg chl a m-2, with highest concentrations observed in dwarf mangrove stands. Benthic algal mats were dominated by cyanobacteria and diatoms in dwarf stands and by filamentous algae and diatoms in tall forest along shorelines. Gross oxygenic photosynthesis in mats ranged from 5 to 30 mmol O2 m-2 h-1. As with chlorophyll, the highest rates of oxygenic photosynthesis were observed in mats inhabiting the dwarf mangrove zone. Vertical accretion of benthic mats was measured above a thin, mesh material (1 mm) pinned to the soil surface with plastic clips. Sites with benthic mats accreted vertically at rates ranging from 1 (tall forest) to over 6 (dwarf forest) mm y-1, rates comparable to mineral sedimentation. Mangrove fine roots grew into these mats, contributing additional organic volume and strength to the accreted material. Carbon (C) and nitrogen (N) accretion rates were 80 and 5 g m-2 y-1, respectively, which agreed with the high primary production measured in the mats. A negative correlation between vertical accretion and tidal flooding may reflect light or CO2 limitation directly affecting mat production or spatial differences in mat species composition. The high primary production rates observed in benthic algal mats indicates they are potentially integral sources of organic matter that may contribute significantly to vertical accretion and soil formation in sediment-poor mangrove habitats. Benthic mats also contribute substantially to C and N accretion and consequently play a key role in biogeochemical cycles in mangrove ecosystems. This information will aid in understanding how coastal ecosystems maintain elevations relative to sea-level rise and in developing global change models that better reflect the biological processes contributing to vertical accretion. Contact Information: K.L. McKee, National Wetlands Research Center-USGS, 700 Cajundome Blvd., Lafayette, LA 70506, USA, Phone: 337-266-8500, Email: [email protected]


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Isotopic and Nutrient Relations of Plants from Coastal Wetlands Regulated by Salinity and Flooding Gradients: The Guanoco Stream in Venezuelas Northeastern Coastal Plain E. Medina1,2, A. M. Francisco1 and A. Quilice3

1 Centro de Ecología, IVIC, Caracas, Venezuela 2 IITF, USDA Forest Service, San Juan, Puerto Rico 3 Departamento de Ecología y Ambiente, PDVSA-INTEVEP, Los Teques, Venezuela

The bidiurnal macrotidal regime (> 2m) in the Paria Gulf at the atlantic coast of Venezuela, and the flat landscape results in the penetration for tens of km of a marine salt wedge into the water course draining the northeastern coastal plain. The associated levels of salinity, tidal flooding, and sedimentation decrease perpendicularly from the river channel into the backswamps. The vegetation varies sequentially from fringe mangroves along river margins, to herbaceous and forest swamps dominated by non-halophytic species in the backswamps that include forests dominated by Pterocarpus officinalis, herbaceous communities of Lagenocarpus guianensis, and mixed forests and palm swamps with Mauritia flexuosa, Chrysobalanus icaco, Tabebuia spp., Clusia spp. Analyses of soil, water, and plant samples along a 1.5 km transect located near the confluence of the Guanoco and San Juan river (Sucre and Monagas States, Venezuela) revealed that: a) conductivity and Na concentration both in interstitial water and soils decreased exponentially from the river fringe to the internal back swamps; b) for most species ∑(K,Na, Mg, Ca) could be predicted from the % Ash of plant material, the few exceptions were probably due to differential accumulation of Si; c) Pterocarpus officinalis and Crinum erubescens showed a large Na-exclusion capacity, a property allowing them to coexist and compete with halophytic mangroves in brackish soils; d) concentration of Na, P, and N decreased monotonously along the transect, however, two site groups were statistically separated, those of the mangrove forest belt (0-700 from river fringe) and those of the backswamps (700-1500 m from river fringe). The statistical analysis performed on the aggregated leaf samples into these groups characterized the backswamps as limited by N and P. The negative δ 15N values of backswamp species are explained by the limited growth capacity determined by nutrient deficiency, restricted organic matter decomposition leading to the formation of purely organic soils, and the closed nature of the N cycling of these communities. By contrast the fringe forest was not nutrient limited, and the open character of their N cycling favors 15N accumulation within the system. Contact Information: E. Medina, Centro de Ecología, Instituto Venezolano de Investigaciones Científicas. Aptdo. 21827, Caracas 1020-A, Venezuela, Phone: +58-212-5041247, Fax: +58-212-5041088, Email: [email protected]


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Recent Discoveries of Surprising Anaerobic Organisms and Novel Pathways J. Patrick Megonigal

Smithsonian Environmental Research Center, Edgewater, Maryland, USA Discoveries since 1990 of several new and surprising forms of anaerobic metabolism promise to revise and expand our understanding of anaerobic metabolism and biogeochemistry in wetland ecosystems. For the most part, research on these processes has not been undertaken in vegetated soils or sediments. My objective is to provide an overview of recent advances in anaerobic metabolism of interest to wetland biogeochemists (Megonigal et al. 2004). Several alternative pathways for producing N2 that do not involve the classical enzyme systems of denitrification have recently been either confirmed or investigated in detail. The contribution of these processes to N2 production is largely unknown, but limited evidence suggests they may be quantitatively important. The most intriguing of these is anammox or anaerobic ammonium oxidation, a reaction that is now known only in marine systems. Anammox consumes 1 mole of NH4

+ (oxidant) and 1 mole of NO3- (reductant) yielding 1 mole of N2. Anammox bacteria have

unusual features such as novel lipids and internal compartmentalization similar to Eukaryotes. Anaerobic methane oxidation is a syntrophic relationship between distantly-related organisms organized spatially in tiny aggregates. Archea occupy the aggregate center where they oxidize CH4 to CO2, then transfer reducing equivalents to Bacteria on the outside of the aggregate that reduce sulfate. The process substantially lowers CH4 emissions from oceans and fuels sulfate reduction. A fruitful area of future research is anaerobic CH4 oxidation in freshwater wetlands linked to Fe(III) or nitrate reduction. Anaerobic oxidation of Fe(II) linked to nitrate reduction was recently discovered. Familiar organisms have recently been shown to perform unexpected types of metabolism, such as nitrifying bacteria that denitrify, Fe(III)-reducers that produce CH4, and methanogens that reduce Fe(III). Such physiological versatility is forcing reconsideration of the role of competition for electron donors in establishing reduction-oxidation gradients in anaerobic soil and sediment. Advances have been made in new and underappreciated electron acceptors. Microbial Fe(III) reduction was assumed to be negligible, but is now known to account for most of the anaerobic carbon metabolism in many wetland sediments. Fe reducers, methanogens and other anaerobic microorganisms have the capacity to reduce humic acids, which are abundant in anaerobic sediments and capable of acting as electron shuttles. Little is known about the extent to which humic acids serve as electron acceptors in natural ecosystems. More discoveries can be expected as the tools of microbiology and biogeochemistry continue to integrate. The significance of these discoveries for wetland systems remains to be determined. Megonigal, J.P., M.E. Hines, and P.T. Visscher. 2004. Anaerobic Metabolism: Linkages to Trace Gases and Aerobic

Processes. Pages 317-424 in Schlesinger, W.H. (Editor). Biogeochemistry. Elsevier-Pergamon, Oxford, UK

Contact Information: J. Patrick Megonigal, Smithsonian Environmental Research Center, Edgewater, MD 21037, Email: [email protected]


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Significance of Coupling of Nitrification and Nitrate Reduction on Water Quality of a Coastal Lake Receiving Nitrate in Diverted Mississippi River Water Shenyu Miao2, R. D. DeLaune1 and Aroon Jugsujinda1

1Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA 2School of Biological and Chemical Engineering, Guangzhou University, Guangzhou

Nitrification (nitrate production) and denitrification (nitrate reduction) rates were estimated simultaneously in sediment-water columns of a coastal lake sediment using a 15N dilution technique. Labeled and unlabeled NO3 were added to surface water of replicated sediment-water columns and change in the concentrations of labeled and nonlabeled nitrate in water were determined over time. The rate of total NO2 + NO3 decreases averaged from two sites was 16.2 mg N m-3 d-1, whereas 15N-labeled (NO2 + NO3)-N decreased at the rates of 5.8 mg 15N m-3 d-1

over the 57 d incubation period. The averaged rates of nitrate reduction and nitrification were 51.8 μmol N m-2 h-1 (43.5 mg N m-3 d-1) and 30.8 μmol N m-2 h-1 (25.9 mg N m-3 d-1), respectively. Results indicate Lake Cataouatche sediment has capacity to process nitrogen via denitrification but nitrification occurring simultaneously with denitrification and was also a significant process contributing nitrate to the system. Water quality issues in Lake Cataouatche associated with nitrate in diverted Mississippi water should consider both the coupling of nitrate reduction of river water nitrate and nitrification of nitrogen in nitrogen enriched lake sediment. Nitrification in bottom sediment is a significant nitrate source and should be factored in the determination of the maximum daily load (MDL) of nitrate the Lake can effectively process. Contact Information: R.D. DeLaune, Wetland Biogeochemistry Institute, School of the Coast and Environment, Louisiana State University, Baton Rouge, LA 70803, Phone: 225-578-6421, Fax: 225-578-6423, Email: [email protected]


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Regulation of Salt Marsh Primary Production, Geomorphology and Biogeochemical Cycles by Variation in Mean Sea Level James T. Morris

University of South Carolina, Department of Biological Sciences, Columbia, SC, USA. Long-term measurements in a South Carolina, USA salt marsh have shown that salt marshes remain in equilibrium with mean sea level (MSL) by virtue of feedbacks between MSL, primary productivity, and sediment accretion. The equilibrium elevation of a marsh, and its productivity, are functions of the rate of sea-level rise (SLR). Primary production is affected negatively by sediment salinity, which is proportional to the relative elevation of the marsh surface. A recent acceleration in the rate of SLR has led to increases in marsh productivity, averaging 32 g m-2 yr-1, and biogeochemical cycling. As the rate of SLR increases, the equilibrium marsh elevation declines, and productivity rises. Increased productivity and flood duration compensate for a higher rate of SLR by promoting an increased sedimentation rate. The system will remain in a stable equilibrium with mean sea level provided that the relative elevation of the marsh surface is super-optimal for marsh productivity. Adjustments in marsh surface elevation are slow in comparison to interannual anomalies and long-period (decadal) cycles of sea level, and this lag in the marsh response results in significant variation in annual primary productivity due to changes in sediment salinity. The long-term (15 yr) increase in primary production at North Inlet has coincided with increases in ammonium, sulfide and soluble reactive phosphate in pore water. Fresh water inputs and anthropogenic impacts are minimal at North Inlet, and concentrations of nutrients in tidal creeks are an order of magnitude lower than in marsh pore water. The source of pore water ammonium is most likely N-fixation, which is linked to the rate of photosynthesis via root exudation of carbon substrates. Soluble reactive phosphate covaries with the sulfide concentration, which is a decay byproduct and competes with phosphorus for iron. Sulfide concentration has risen significantly as primary production has increased over the last 15 years. Thus, the entire biogeochemical system is adjusting to changes in relative MSL and rate of SLR. Contact Information: James Morris, Program Officer, Ecosystem Studies Program, University of South Carolina, Department of Biological Sciences, Columbia, SC, USA, Phone: 703-292-7183, Email: [email protected]


72

Carbon and Nitrogen Mineralization of Cowdung and Poultry Manure Amended Soil under Anaerobic Condition Umme A. Naher

Soil Science Division, Bangladesh Rice Research Institute, Gazipur, Bangladesh A pot experiment was conducted in the Bangladesh Rice Research Institute glasshouse to study the carbon and nitrogen mineralization from the fresh application of cowdung (CD) and poultry manure (PM) under wetland condition. Five kg soil sample was taken in plastic pots and cowdung and poultry manure were added @ 2.5, 5.0 and 10 g carbon per kg soil and an unamended control soil was maintained. The pots were watered to submerged conditions and incubated in glass house (35±2 OC) for 180 days. Duplicate soil samples were analyzed for organic carbon, NH4

+ and NO3- at every 15 days and CO2 was also measured. The carbon

mineralization pattern in CD and PM amended soils were identical and followed the first order kinetics. Initially the mineralization rate was higher (k= 0.085) and after 40 days it becomes slower (k = 0.028) and at 75 days it was 0.017. After 75 days 26-28 percent organic carbon from CD and 30-43 percent from PM was mineralized. CO2 flux was faster in first 4 days and become slower then, however, the evolution of CO2 from CD and PM was observed up to 40 days, particularly, the soil received 10 g C/ kg soil. The highest cumulative CO2 flux 0.55mg/g soil was observed in pot receiving 10g carbon/kg soil from CD and in case of PM it was 0.047mg/g soil, while in control pots the lowest (0.18mg/g soil) CO2 was produced. With the increase in doses of CD and PM, the concentration of NH4

+ was increased. After 30 days of incubation, PM amended soil (10 g C/kg soil) gave NH4-N (206 ppm) while the CD amended soil produced 53 ppm NH4+

--N. The total carbon mineralization was higher in PM than CD due to low C: N in the former. Contact Information: Umme Aminun Naher, Scientific Officer, Soil Science Division, Bangladesh Rice Research Institute, Gazipur 1701, Bangladesh, Phone: +880 2 9263603, Fax: +880 2 9262734, Email: [email protected]


73

An Assessment of the Human Impact on a Tropical Coastal Wetland Ecosystem K. Shadananan Nair

Centre for Earth Research & Environment Management, Vaikom, Kerala, India Wetlands, the unique natural water purifiers and life supporting systems face serious challenges from environmental changes and human impacts all around the World. This is more serious in developing countries where protection and management of wetlands are difficult due to lack of finance and social and political problems. The Vembanad-Kol wetland in the State of Kerala in India is a good example. This is a typical coastal wetland with most of the area lying nearly one metre below sea level. Through generations, rice cultivation has been made possible by constructing dikes and pumping out water. Measures to multiply crop production and projects to prevent brackish water intrusion and evacuation of floodwater deteriorated the soil and surface and groundwater in the entire wetlands area. Control of natural water flow through regulators disturbed the natural flushing causing concentration of pesticides, fertilisers and industrial and domestic wastes on logged water. The projects to prevent brackish water intrusion produced negative results and the targeted rice production could not be achieved. Rate of deterioration is so large that freshwater resources in many locations are no more usable. Many native species of living organisms faced extinction and the challenge still continue. The wetland with rich biodiversity, capable of providing livelihood for millions in the area is under threat also from the indiscriminate utilization, encroachments, reclamation, sand quarrying and urbanization. Protection of these wetlands is vital as demands for water and food increase with rapid rise in population, while availability and production decrease fast. Even with three times the global average rainfall and fertile land, Kerala experiences serious seasonal water shortage and food crisis because of the lack of proper conservation and protection schemes. Wise use of the wetlands could solve this to a good extend. The proposed water diversion scheme in the east lying rivers is likely to dump more pollutants into the wetlands, worsening the situation. Increasing tourism activity adds plastic, oil, grease and bio wastes. In this study, the detailed analysis of the various issues leading to the degradation of soil and water in the wetlands and the possible changes associated with population and climate change has been made. Input of chemicals and their impacts on the water and organisms have been assessed. Results point towards hazards in wetlands environment in near future. For the protection of wetland, the State needs an adequate environmental policy and a strong political will to implement it. Some suggestions for policy guidelines have been presented. Contact Information: K. Shadananan Nair, Centre for Earth Research & Environment Management, Vallayil House, North Gate, Vaikom-686141, Kottaym Dt., Kerala, India, Phone: +91-4829-224264, Email: [email protected]


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Nitrogen Cycling and Ecosystem Exchanges in a Virginia Tidal Freshwater Marsh Scott C. Neubauer1,2, Iris C. Anderson2 and Betty B. Neikirk2

1University of South Carolina, Baruch Marine Field Laboratory, Georgetown, SC, USA 2The College of William and Mary, School of Marine Science, Virginia Institute of Marine Science, Gloucester

Point, VA, USA Tidal freshwater marshes are diverse habitats that differ both within and between marshes in terms of plant community composition, sediment type, marsh elevation, and nutrient status. Because our knowledge of the nitrogen (N) biogeochemistry of tidal freshwater systems is limited, it is difficult to assess how these marshes will respond to long-term progressive nutrient loading due to watershed development and urbanization. We present a process-based mass balance model of N cycling in Sweet Hall marsh, a pristine (i.e. low nutrient) Peltandra virginica/Pontederia cordata-dominated tidal freshwater marsh in the York River estuary, Virginia. The model, which was based on a combination of field and literature data, revealed that nitrogen cycling in the system was largely conservative. For example, the mineralization of organic nitrogen to NH4

+ provided almost twice as much inorganic N as was needed to support marsh macrophyte and benthic microalgal primary production. Efficient utilization of porewater NH4

+ by nitrifiers and other microbes resulted in low rates of tidal NH4+ export from the marsh

and little accumulation of NH4+ in marsh porewaters. Inputs of nitrogen from the estuary and

atmosphere were not critical in supporting marsh primary production, and served to balance N losses due to denitrification and burial. A comparison of these results with the literature suggests that the relative importance of tidal freshwater marsh N cycling processes, including plant productivity, organic matter mineralization, microbial immobilization, and coupled nitrification-denitrification, are largely independent of small-scale changes in water column N loading. Although very high (millimolar) concentrations of dissolved inorganic N can affect processes including denitrification and plant productivity, the factors that cause the switch from efficient N recycling to a more open N cycle have not yet been identified. Contact Information: Scott C. Neubauer, University of South Carolina, Baruch Marine Field Laboratory, Post Office Box 1630, Georgetown, SC 29442, USA, Phone: (843) 546-3623 x240, Fax: (843) 546-1632, Email: [email protected]


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Meeting the Challenge of Meshing Dual Roles for Stormwater Treatment Areas in South Florida Jana Majer Newman

Everglades Division, South Florida Water Management District, West Palm Beach, FL Natural and constructed wetlands have been extensively studied and documented as a viable means of removing excess nutrients from point and non-point surface sources throughout the world. Constructed systems range in size from small units sized for single-family waste water treatment, to large Stormwater Treatment Areas (STAs) that were constructed in south Florida to aid in the restoration of the Everglades ecosystem. Along with nutrient removal, the public and policy makers expect constructed wetlands to also provide ancillary benefits, such as aesthetics, recreation, wetland habitat, aquifer recharge, water supply, or as in the case of the STAs, flood protection. However, nutrient removal efficiency may be compromised when it is necessary to support a secondary benefit. The STAs were originally designed to achieve outflow TP concentrations of 50 µg/L, and are now being modified to achieve the lower phosphorus criterion of 10 ug/L. To meet the original outflow requirements, the size of the STAs was based on a specific design envelope. Specifically, the long-term average annual inflow volume anticipated for STA-1W during design was approximately 160,000 acre-feet (221 cfs), and an average annual TP loading of approximately 27,372 kg with an assumed mean inflow concentration of approximately 139 ug/L. During 2004, the 365-day cumulative flow to STA-1W had generally exceeded the maximum design envelope, and the 30-day cumulative inflow volume had experienced a sharp increase beginning August 2004. Additionally, as a direct result of hurricanes Francis and Jeanne and the need to provide additional flood control within the system, the hydrologic loading to STA-1W in September 2004 alone was 109,912 acre-feet, which accounted for more than 65% of the average annual design inflow. Preliminary assessment of data indicates a peak monthly mean TP inflow concentration during September 2004 of about 296 ppb. This elevated TP concentration, combined with the increased flows, resulted in a sharp increase in the 30-day cumulative loading rates beginning September 2004, and a sharp decrease in TP removal efficiency. Preliminary results indicate that STA TP removal performance is related to TP inflow concentrations and aerial loading rates. Recent data indicates that if loading rates are maintained at or below the mean design envelope following a period of high loading, then the system recovers and TP percent load reduction increases. Indicating that while even short-term operational changes necessary to provide vital flood control efforts may have a negative impact on the nutrient removal efficiency, the impact appears to be reversible. Additional monitoring and research is needed to assess the frequency and extent that these perturbations may continue before, or if, irreversible degradation to TP removal performance occurs. Contact Information: Jana Majer Newman, Ph.D., South Florida Water Management District, Everglades Division, 3301 Gun Club Road, West Palm Beach, FL 33406, Phone: 561.682.2820, Email: [email protected]


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Phosphorus Enrichment and Restoration of the Everglades S. Newman1, P. V. McCormick2, K. R. Reddy3 and B. L. Turner4

1Everglades Division, South Florida Water Management District, West Palm Beach, FL, USA 2Leetown Science Center, U.S. Geological Survey, Kearneysville, WV, USA 3Wetland Biogeochemistry Laboratory, Soil and Water Science Department, University of Florida, Gainesville,

FL, USA 4 Smithsonian Tropical Research Institute, Balboa, Ancon, Republic of Panama

The historically phosphorus (P)-limited Everglades, is one of the most studied peatlands in terms of P biogeochemistry. Over 30 years of anthropogenic P enrichment has resulted in the conversion of several thousand hectares of the ridge and slough landscape into monotypic Typha domingensis communities. A key component in restoring this ecosystem was to determine the sensitivity of the Everglades to P inputs and the level of P that causes an imbalance in flora and fauna. The overarching hypotheses behind the research were: 1) structural and functional changes observed along gradients with distance from inflow structures and canals were primarily attributable to P enrichment and, 2) different wetlands compartments have different rates of response to P enrichment. The majority of the research was conducted in the northern Everglades, where P enrichment has caused the loss of one of the most sensitive microbial communities, the calcareous periphyton mat. This loss, combined with increased macrophyte productivity caused a decline in water-column productivity, which, in conjunction with increased decomposition rates, resulted in reduced dissolved oxygen concentrations and a switch from aerobic to anaerobic carbon cycling in P-enriched areas. In combination, these changes reduce habitat quality and impact higher trophic levels. The majority of these changes occurred as surface water and soil total P concentrations increased above background levels, which were ≤ 10 µg L-1 and ≤ 500 mg kg-1, respectively. As a result, the Class III water quality criterion for P in the Everglades was set at 10 µg L-1 and P impacted areas were defined as those sites with surficial soil total P concentrations > 500 mg kg-1. Total P concentrations worked well in establishing the P criterion and identifying P impacted areas. However, as Everglades restoration continues, more detailed analysis of P chemistry is essential if we are to minimize the release of P from currently enriched areas to downstream more pristine regions. Previous studies showed that over 70% of the soil total P pool was bound in organic form and there was an inverse relationship between soil total P concentration and alkaline phosphatase activity; one of the most studied mechanisms of organic P turnover. Recent studies of alkaline extracts of benthic floc and soils using solution 31P NMR spectroscopy indicated that phosphodiesters such as DNA and phospholipids dominate the organic P pool. Thus, the hydrolysis of phosphodiesters appears to be the rate-limiting step in organic P turnover in the Everglades and mechanisms that regulate this need further examination. The influences of changing hydrologic conditions are of particular importance as hydrologic restoration of the Everglades continues. Contact Information: S. Newman, Everglades Division, South Florida Water Management District MSC-4440, P.O. Box 24680, West Palm Beach, FL 33416-4680, USA, Phone: +1-561-682-6608, Fax: +1-561-682-5608, Email: [email protected]


77

Nutrient Transformations During Floodplain Inundation Durelle Scott, Judson Harvey and Gregory Noe

U.S. Geological Survey, Reston, VA, USA Floodplains can import, export, and/or transform nutrients during flooding in river-floodplain ecosystems. This nutrient processing represents one of the last opportunities for the retention of riverine nutrient loads before discharge to coastal oceans, many of which are experiencing the negative effects of eutrophication. We quantified the fate of nitrogen (N) and phosphorus (P) in floodplain sloughs of the Tangipahoa River, Louisiana, in an effort to understand the processes that affect nutrient loading to Lake Pontchartrain. We monitored changes in surface and subsurface N and P concentrations and added experimental tracers to mesocosms during floods in late winter and spring 2004. Nitrate rapidly disappeared from surface water in both sloughs during the January and March floods. Ammonium, however, increased in the slough closer to the river (slough A) and decreased in the slough farther from the main channel (slough B) during both floods. Dissolved and particulate organic N concentrations generally did not change during the floods. Dissolved reactive phosphorus concentrations decreased in both sloughs. Vertical profiles of nutrient concentrations from surface water through multiple depths of subsurface water showed strong gradients in some nutrient fractions. Nitrate disappeared in the first 0-3 cm of sediment. Below this depth, ammonium and total dissolved P concentrations greatly increased. Dissolved organic N concentrations generally did not change with depth. Results of an isotopic nitrogen tracer addition suggested that denitrification was the primary mechanism for nitrate removal, both in surface water that contacted the sediment surface and in subsurface water recharging the aquifer. Denitrification completely removed nitrate in surface water and in recharging subsurface water within several days. Dosing of surface water in mesocosms with Br- tracer showed that recharge to the aquifer occurred on the falling limbs of floods in slough B. In slough A, groundwater discharged to surface water on the floodplain. Thus, the two sloughs have very different surface-subsurface relationships despite their close proximity (~100 m). Peak subsurface ammonium concentrations occurred next to the sediment-water interface in slough A and at much greater depth in slough B. These results indicate that floodplains of the Tangipahoa River are able to efficiently remove nitrate and phosphate during flooding events, but that particulate and dissolved organic N are not retained. In addition, subtle differences in geomorphology and hydrology resulted in large changes in ammonium export and surface-subsurface redox gradients. In conclusion, site hydrogeomorphology had a large influence on nutrient cycling in the floodplain of this Southeastern USA river. Contact Information: Greg Noe, U.S. Geological Survey, 430 National Center, Reston, VA 20192, Phone: 703-648-5826, Fax: 703-648-5484, Email: [email protected]


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The Role of Particulate Phosphorus in Everglades Wetlands Gregory Noe1, Judson Harvey1 and James Saiers2

1U.S. Geological Survey, Reston, VA 2Yale University, New Haven, CT

The transport of suspended particles is an important process that regulates ecosystem structure in wetland ecosystems of the Everglades and elsewhere. Particle transport is likely a key process for maintaining topographic heterogeneity and influencing the movement of nutrients in wetlands. Particle generation, transport, and retention are also important for understanding phosphorus (P) cycling. At present, the composition, concentration, and transport of suspended particles are all poorly understood in the Everglades and other wetlands. Given the potential importance of suspended particles, we have initiated studies of particle characterization and transport in Everglades wetlands. Our sampling of surface water from Loxahatchee National Wildlife Refuge (site LOX8), along a P-enrichment gradient in Water Conservation Area 2A (sites F1, F4, and U3), and Shark River Slough in Everglades National Park (site SRS-A) has shown the importance of particulate P. Particulate P and N were analyzed directly, as well as indirectly by difference between unfiltered and filtered samples. Estimates of particulate P differed widely between the direct and indirect methods, and indirect measurements were less precise. Particulate P concentrations were lowest at SRS-A (0.06 μM) and unenriched U3 (0.10 μM), intermediate at LOX8 (0.19 μM) and partially enriched F4 (0.18 μM), and greatest at enriched F1 (0.31 μM). Particulate P varied from 23% to 47% of total P in the surface water. This proportion was positively correlated with suspended sediment concentrations. Particulate N:P ratios decreased from 38 (U3) to 15 (F1) along the P-enrichment gradient, suggesting that particles are more labile in P-enriched marshes of the Everglades. In addition, the 0.45 to 2.7 μm fraction was the dominant size of particulate P at all sites. In contrast to P, particulate nitrogen (N) comprised just 2% to 7% of total N. The greatest concentrations of particulate N occurred in the 2.7 to 10 μm size class. The differential size distribution of particulate N and P may indicate different sources of particles in different size classes. These results show that 1) particulate P can be a large proportion of total P in the water column, 2) direct measurement of particulate P is necessary, and 3) particles carry a small proportion of the N load in surface water of the Everglades. Future work will further characterize the transport characteristics of suspended particles.

Contact Information: Greg Noe, U.S. Geological Survey, 430 National Center, Reston, VA 20192, Phone: 703-648-5826, Fax: 703-648-5484, Email: [email protected]


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Organic Matter and Amino Acids in Wetlandsoils J. Omote

Environmental Eco Technology Institute, Tokyo & Kinki University Technical College, Department of Architecture and Civil Engineering, Mie, Japan

Wetlands are regarded as a complex habitattype, in their full range of development-from oligotrophic to mesotrophic, eutrophic and dystrophic, calcareous fens to acidic bogs, lowland swamps to marsh etc. They occupy a wide range of environmental conditions and dynamic systems which form part of the hydroseral succession from open water to dry land sustain a rich variety of plant species (submerged algae, rooted submerged and floating species, rooted floating-leaved species,emergent reed and grasses, fen plant and bogs plants usw). These wide range of environmental conditions in wetlands exert edaphic factors which influence plant growth and distribution.The portion of organic matter in wetlandsoils amount to more than 30% mass. A high concentration of organic matter is an important nutrients of plant growth. The rates of decomposition process of organic matter are determined by nature of components of plant species. This mean, a very close relation between plant species and organic matter. The organic matter can exert a profound influence on soil properties and ecosystem functioning. The soil organic matter was composed of a heterogeneous mixture of dominantly colloidal organic substances containing acidic functional groups and N.

The structures of lignin and microbial origin polymerize in the presence of N containing groups, amino acids, peptides, and proteins to produce nitrogenous polymers( Flaig et al., 1975). The form amino acids and mineralization of amino acid N to form NH4+ provide sources of N for soil biological processes. The degree and accumulation of decomposition of organic matter and amino acid in wetland varies on wetland types or mire classification types.Therefore, an investigation on the plant species in wetlands with variation in organic matter and its components will be discussed in this paper. The results of these studies suggest that there is a clear difference in soils organic matter (Humine,Humic acid,Fulvic acid,Bitumen) among river, fen,transitional mire and bogs. and the ratio of each components in the soil. Nitrogen and Phosphorus are positively correlated with fulvic acid. Negative correlation are Humic acid and C/N ratio. As for amino acids, Asparatic acid comes first in order of amount, and then Arginine, Glycine, Alanine and Lysine in Fen. In Transitional mire Glycine comes first in order of amount, and then Asparatic acid ,Arginine or Alanine and Glutamic acid. In Raised bogs Argine and Glycine comes first ,and then Asparatic acid, Alanine, and Glutamic acid in that order. The differences of variety rate of amino acids may be attributed to the influence of the distribution of plant species and Wetlands classification. Contact Information: J. Omote, Environmental Eco Technology Institute, 4-38-7 Hon-cho, Nakano-ku, Tokyo, Japan, Phone & Fax: +81-3-3381-0218, EMail:[email protected]


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Phosphorus Removal Performance of a Harvestable Pasture Grass Cultivated in a Treatment Wetland Patrick Owens and Thomas A. DeBusk

DB Environmental, Inc., Rockledge, FL In south Florida, treatment wetlands are being proposed for removing phosphorus (P) from agricultural drainage waters (ADW) that enter Lake Okeechobee. There is some concern, however, over the ability of constructed wetlands to provide long-term, sustainable removal of P. One potential method of enhancing sustainability is to remove P from the system through routine harvesting of biomass. Prior studies with productive aquatic macrophytes, however, have shown that this approach can be cost prohibitive unless there is an economically valuable use for the harvested material. We performed a mesocosm-scale study from February 2003 to June 2004 to evaluate the P removal performance of a harvestable pasture grass (paragrass) grown under flooded (15 cm deep) conditions. Paragrass is a productive grass common to the region, which can be used as green chop for cattle feed. ADW containing approximately 400 µg TP/L was fed semi-continuously to the surface of the mesocosms at a hydraulic loading rate (HLR) of 5 cm/day, and was discharged both under surface flow (from the water column) and subsurface flow (through a soil under-drain) configurations. We also compared P removal performance of paragrass to cattail, which commonly is a dominant species in shallow treatment wetlands. These mesocosms were operated under surface outflow conditions at a HLR of 10 cm/day. Paragrass cultured under surface flow conditions provided lower mean outflow TP concentrations than under subsurface configurations (154 vs. 210 µg/L). We also observed differences in P speciation, with the surface flow systems exhibiting lower outflow soluble reactive P levels, and higher particulate P concentrations, than the subsurface flow systems. In a second study, paragrass exhibited a lower outflow TP concentration than did the cattail (226 vs. 290 µg/L) over the course of the experiment. Mass P removal rates by the respective systems were 9.0 and 6.8 gP/m2-yr. Paragrass was harvested three times between March and November 2003, providing a mean foliage dry weight productivity of 5.6 g/ m2-day. Average tissue P content for the paragrass was 2371 mg P/kg. This translates into a mean foliage P removal rate of 13.4 mg P/m2-day or 4.9 g P/m2-yr. The harvested plant tissue therefore represented 54% of the total phosphorus (9.0 g/m2-yr) removed from the water column. These findings demonstrate that a paragrass-based treatment wetland, with periodic harvest of the biomass, can provide effective P removal from ADWs. Larger-scale studies should be performed with this plant to evaluate appropriate methods for harvesting the foliage from full-scale systems. Contact Information: Patrick Owens, 365 Gus Hipp Boulevard, Rockledge, Florida, 32955, USA Phone: 321-639-4896, Fax: 321-631-3169, Email: [email protected]


81

Horizontal and Depth Distribution of Soil C, N and P in a Seasonal Wetland, China Genxing Pan1, Chuande Chi1, Lianqing Li1, Xinwang Xu2 and Xinmin Wu2

1Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing, China

2Chizhou Teachers College, Anhui Province, China

There are an area of seasonal wetlands in the low reaches of the Yangtze River, China, which are important generally in flood regulation and prevention of wild birds. Eutrophication in these wetlands has become serious for the last decades. The wetland soils are subject to waterlogging in summer and dried in autumn to winter every year. Vigorous growth of grass occurs in these wetlands usually after summer when the water table of Yangtze River drops. In order to address the role of soil nutrient status and the seasonal dynamics in the water quality a study of soil major nutrient and the depth distribution was conducted in Shengjin Lake wetlands in Anhui Province, a National Wetland Preservation Area of China since 1991. Soils from a wetland in the Anhui Province, China were sampled by depth interval to 1m nearby. Total C, N and P of the soil samples was determined by CNS Elemental Analyzer and Colorimetry respectively. Soil organic carbon, nitrogen and phosphorus are generally very rich (up to 23 g/kg SOC, 25 g/kg and 0.7 g/kg respectively) compared with those of nearby agricultural soils and highly stratified in topsoil of 30cm depth. Small horizontal and large vertical variation of the determined elements is found in the wetland soils. The high superficial accumulation of soil nutrients may implicate that the soils receive nutrient from the catchment water flow in submerging period and could release to water again upon mineralization in dry season after summer. The relative contribution of the mineralized nutrients to water eutrophication deserves further study. Contact Information: Genxing Pan, Nanjing Agricultural University, Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095 China, Email: [email protected]


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Effects of Co-Occurring Agricultural Pollutants on Nitrogen Removal by a Constructed Coastal Wetland Michael F. Piehler1, Sara W. McMillan1, Suzanne P. Thompson1 and Amy C. Poe2

1UNC Chapel Hill Institute of Marine Sciences, Morehead City, NC 2Janicki Environmental, St Petersburg, FL

The current and future water quality of the Neuse River Estuary (NRE) has been the focus of significant attention from scientists, decision makers and the public at large. Nitrogen has been identified as the primary driver of excessive phytoplankton production in the estuary that has led to negative water quality impacts in the NRE. The Neuse River Nutrient Sensitive Waters Management Strategy includes rules for wastewater, urban stormwater, agriculture and general nutrient management. Utilization of agricultural Best Management Practices (BMPs) is among the alternatives for agricultural operations in the NRE to become compliant. Understanding the effectiveness of BMPs such as constructed wetlands is critical to assessing the success of nutrient reduction efforts. A wetland was constructed on Open Grounds Farm (OGF), a 45,000 acre row-crop farm in eastern North Carolina in the spring of 1999. The wetland was designed to decrease the loading of nutrients and sediment from OGF to the South River and eventually the NRE. Loading of nitrogen and phosphorus entering and leaving the wetland have been monitored since its construction. Additionally, denitrification rates in the wetland were measured for 2 years using membrane inlet mass spectrometry. Here we present the results of experiments designed to assess the effects of substances in agricultural runoff on rates of denitrification. Nitrogen, phosphorus, organic carbon and sediment were added to cores that were assayed for rates of denitrification. Particulate organic carbon and dissolved organic carbon additions both increased rates of denitrification in nitrate amended cores. Phosphorus additions either slightly enhanced or had no impact on rates of denitrification. The addition of sediment decreased the rates of denitrification in nitrate amended cores. Preliminary attempts to correlate loads of these substances to the wetland with rates of denitrification measured in the wetland have not yielded conclusive results. Understanding the potential impacts of these compounds on nitrogen removal by the wetland may be of use for improving management in the watershed and potentially optimizing the performance of the wetland as a nitrogen filter. Contact Information: Mike Piehler, The University of North Carolina at Chapel Hill, Institute of Marine Sciences, 3431 Arendell Street, Morehead City, NC 28557, Phone: 252-726-6841X160, Fax: 252-726-2426, Email: [email protected]


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Biotreatment of Municipal Wastewater with Constructed Wetlands at Oahu, Hawaii P. A. Pier, R. A. Almond and L. L. Behrends

Tennessee Valley Authority, Muscle Shoals, AL The constructed wetlands system, located just north of the city of Wahiawa on the island of Oahu, Hawaii, consists of a solids settling tank and three gravel subsurface-flow cells in series. The first two cells (each 26.8 m long, 26.2 m wide, 1.2 m deep) comprise the patented reciprocating wetlands technology. This consists of two adjacent subsurface-flow wetland cells configured in a serial flow-through system, which are alternately filled and drained by pumping water periodically from one cell to the other. This provides rapid and frequent oxygenation of the root zone and gravel substrate biofilm to enhance aerobic processes. These cells were planted with four cultivars of heliconia (Heliconia sp.), an ornamental/cut flower plant. The third cell (26.5 m long and 22.6 m wide), which was anoxic, was planted with a wetland grass cultivar (Paspalum vaginatum Sw. ‘Tropic Shore’). The wetland cells had a total retention time of three days (two days in the reciprocating cells, one day in the anoxic cell) at a hydraulic loading rate of 60,000 gal/day. Primary sewage flow was diverted from a sewer line into the solids settling tank, which had a capacity to handle 120,000 gal of influent a day with a retention time of one day. Water leaving the settling tank flowed into the wetlands. Initial testing was conducted at an influent flow rate of 47,000 gal/day, starting in January 2001, with 5-week test periods (TP) having combinations for the number of pumps operating during reciprocation/hours of hold time between each reciprocation consisting of 1:1 for TP 1, 2:1 for TP 2, 4:0 for TP 3, 4:3 for TP 4, 2:4 for TP 5, and 2:2 for TP 6. Following optimization testing, a steady-state period (2:2) was run from September 2001 until March 2002, to assess the performance of the wetlands system over an extended period. In March 2002, input flow rate was increased to100,000 gal/day to test the limitations of the wetlands system, with pumps/hold time of 3:2 for TP 7 and 3:1 for TP 8. A second steady state period with 60,000 gal/day and 4:1 pumps/hold time was run from August 2002 to February 2003. Average influent concentrations were 24 mg/L NH4-N, 0.01 mg/L NO3-N, 34 mg/L total N, 130 mg/L BOD5, 54 mg/L TSS, and 5.6 mg/L total P. For influent flows of 47,000 and 60,000 gal/day, all pumps/hold times reduced effluent concentrations to 1-2 mg/L NH4-N, less than 1 mg/L NO3-N (except TP 2 and 3), less than 3 mg/L total N (except TP 2 and 3), 1-4 mg/L BOD5, and 1-3 mg/L TSS. Total P removal was not as effective, with effluent concentrations of 1-5 mg/L. The reciprocating cells alone were effective in contaminant removal, with effluent concentrations of 1-5 mg/L NH4-N, 0.4-4 mg/L NO3-N (indicating that an anoxic/anaerobic zone was present in the reciprocating cells for denitrification), 2-12 mg/L BOD5, and 2-8 mg/L TSS. At 100,000 gal/day inflow, the system could not maintain this level of water quality, and hydraulic functioning for reciprocation was also impaired. This project was administered by the United States Army and the United States Department of Agriculture, and conducted with Dole Food Company. The authors wish to acknowledge the on-site work of James Crittendon (retired), Dole Food Company. Contact Information: P. Pier, Tennessee Valley Authority, CEB 1C-M, P.O. Box 1010, Muscle Shoals, AL 35662, Phone: 256-386-2789, Fax: 256-386-2191, Email: [email protected]


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Decomposition of Mangrove Roots in Different Hydrogeomorphic Mangrove Sites in South Florida N. Poret1, R. R. Twilley2 and V. Rivera2

1University of Louisiana , Lafayette, LA, USA 2Louisiana State University, Wetland Biogeochemistry Institute, Baton Rouge, LA, USA

Decomposition is an important ecological process that contributes to nutrient cycling and is one of the key processes controlling rates of soil formation. Decomposition rates depend on both the quantity and quality of organic matter, the hydrological regime, the oxic/anoxic environment and the decomposer community. In the mangrove ecosystem in Everglades National Park (ENP), Florida, both nutrient cycling and soil formation are important to the development and stability of these coastal forests. Aboveground decomposition of mangrove leaf litter has been well studied, but studies of belowground processes are lacking. Belowground decomposition rates of mangrove roots along environmental gradients of vertical depth, soil fertility and hydrology in ENP were determined using 40 cm mesh bags containing mangrove roots. These bags were buried vertically to a 42 cm depth in six sites in the park that are located along nutrient and hydroperiod gradients. The bags were buried in May 2004 and incubated under natural conditions for seven months after which the amount of mass lost was compared to the original amount of material buried. Refractory and labile components of root material using the CHN elemental analyzer was determined to understand their relative contribution to nutrient recycling and soil formation. Contact Information: N. Poret, University of Louisiana, Lafayette, LA, Phone: 1-337-886-7537, Email: [email protected]


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Seasonal Nitrogen Dynamics in the Pichavaram Mangrove Forest, India M. Bala Krishna Prasad and AL. Ramanathan

School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India Nitrogen is one of the essential elements to a variety of biological and chemical processes, both at the organismic level and on the scale of ecosystem. The distribution dynamics of these essential elements are influenced by several driving forces like seasonal variations, salinity and other biological factors. Seasonal induced variations in nitrogen dynamics is important in the Pichavaram mangroves (Lat11˚ 20′, Long 79˚ 47′). A flushing rate of nutrients and salinity was calculated by analyzing a plot of nutrients and salinity versus time for four different seasons. In premonsoon a flushing rate of 1.13 % m-1 of saline water from the mangroves was observed. This flushing rate was nearer to the nitrate rate (1.25% m-1), implying that freshwater nitrate input has a significant impact over nitrate concentration in the mangrove water. We have also observed that net gain of DIN (1.14% m-1) is more than TN (0.84% m-1), which suggests conversion from inorganic to organic form was minimal. The same trend was observed in monsoon also. But in post monsoon and summer reverse trend was observed. 1.68% m-1 and 1.27 % m-1 flushing rate were observed in post monsoon and summer seasons respectively. This is corresponds to loss of nitrate is 1.5% m-1 and 0.65% m-1 in post monsoon and summer respectively. We have also observed significant correlation were found for salinity against nitrite (+ nitrite) (r2 = 0.635) in summer. The percent loss of TN (1.39% m-1 and 0.64% m-1) was higher than that of DIN (1.04% m-1 and 0.55% m-1), which suggests a net transfer from inorganic to organic nitrogen. These changes were agreed with chlorophyll a concentration. The results reveal that the potential significance of conversion of nitrogen to organic nitrogen and vice versa is important in the mangrove nitrogen mass balance budgets models. Significant nitrogen fixing azotobacters and high levels of total N2 in decomposing leaf litter attract animal resources was observed in the Pichavaram mangrove. Thus it acts a ‘mangrove vegetation trap’ to increase decomposition of mangrove litter. This facilitates to increase the yields of fish and prawn by three fold. From this it is clear that mangrove nitrogen dynamics is directly and indirectly related to seasonal variation and nitrification - denitrification mechanisms. Contact Information: M. Bala Krishna Prasad, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi - 110067, India, Phone: +91-9871412755, Email: [email protected].


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Important of Natural Wetlands for Polluted Water Treatment Igor Prokofev and Ludmila Zhirina

Bryansk State Engineering-Technology Academy and Environmental NGO VIOLA, Bryansk, Russia During the communistic period of a history of Russia there was a big program on drainage of wetlands for creation of the new areas of the agricultural fields. This program was not effective, but it became the reason of disappearance of many natural wetlands. Today, Bryansk region is the most polluted Russian region. The one third part of territory has radioactive pollution after the Chernobyl Accident. Therefore, we have objective to study the important role of natural wetlands in maintenance of a high biodiversity and treatment of the polluted water. During 1999-2004 we studied 22 wetlands. Some from them were on radioactive-polluted territory. Our researches have proved that native vegetation effectively accumulates biogenic elements, metals and pesticides, and clears waters from pollutants. For example, the reed accumulates heavy metals and pesticides in the root system. Therefore, bottom sediment accumulates many pollutants and takes out it from cycle of matter. We studied ability to clear water of other plants too. We founded that the quality of water clearing depends on speed of flow velocity of water and from a biodiversity of wetlands. We observed the best water clearing on wetlands with slow flow velocity and the greatest variety of plants. These data can be useful for development new constructed wetlands. On radioactive-polluted territories dangerous pollutants of waters are artificial radioactive isotopes which have dissipated in an environment after the Chernobyl Accident. Radionuclides migrate in an environment and through trophic circuits. It is dangerous for people, because, human body can be polluted by radionuclides through food. Plants and animal accumulate in themselves radionuclides. Water concentration is less them radionuclide concentration in organism. Plants accumulate radionuclides approximately in 2,5 times less, than algae. But the plants, forming calcium incrustations on a surface of leaves, most effectively accumulate radioactive strontium. We revealed two processes which can be after dying off of vegetation during the autumn period before cold winter. Plants, which after dying off fall on a bottom, provide accumulation of radionuclides in bottom sediment. As a result of this process, wetlands become natural depository of radionuclides. It takes out radionuclides from cycle of matter. Plants, which have air holes inside stems (cattail, horsetail, cane), promote secondary distribution accumulated radionuclides. Parts of these lightweight plants during autumn and winter periods are distributed by a wind on many kilometers from wetlands. Contact Information: Igor Prokofev, Post Box 325, 241050, Bryansk, Russia, Phone: +7 (0832) 63-81-59, Email: [email protected]


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Changes In Humic Acid Type In Cowdung And Poultry Manure Amended Wetland Soils F. Rahman, U. A. Naher, A. T. M. S. Hossian, M. A. Saleque and M. A. M. Miah

Soil Science Division, Bangladesh Rice Research Institute, Gazipur, Bangladesh The degree of humification of the humic acid fraction plays an important role in the mineralization of nitrogen from soils. A pot experiment was conducted at the Bangladesh Rice Research Institute glasshouse to study the degree of humification of cowdung (CD) and poultry manure (PM) under wetland soil condition. Five kg soil sample was taken in plastic pots and cowdung and poultry manure were added @ 2.5, 5.0 and 10 g carbon per kg soil and an unamended control soil was maintained. The pots were incubated under submerged conditions in the glasshouse (35±2 OC) for 180 days. Duplicate soil samples were analyzed at every 30 days by extracting with 0.10 M NaOH solution and extract was acidified and re-alkalized to separate humic acid and fulvic acid. Humic acid and fulvic acid were estimated with the oxidation of 0.1N KMO4 solution and the excess 0.1N KMO4 was titrated with 0.1N FeSO4 solution. The amount of humic and fulvic acid were estimated as the amount of 0.1N KMO4 consumed by the soil extract. The optical densities humic acid fraction was determined at optical density of 340 to 700 nm with an interval of 20 nm. The concentration of humic and fulvic acids was not changed due to CD of PM application from 30 to 180 days of incubation. The percent of humic acid in the extracted humus (PQ) was about 48-50% from 30 to 180 days. The effect of CD and PM application on the PQ was not significant. The Δlog K (difference in the log of absorption of 400 and 600 nm) of the control, CD and PM amended soils was above 0.81 from 30 to 150 days, which indicate that the humic acid of the soils was Rp type - humic acid originated from lignin. At 180 days of incubation, the ΔlogK of the control soil was 0.92 but it was reduced in CD and PM treated soils. The soil received CD gave ΔlogK of 0.73 and that received PM showed a ΔlogK of 0.85. The results indicate that the application of CD and PM tended to change the humic acid type, but it took a period of about six months. The application of CD changed the humic acid type from Rp to B type, which contains primary alcohol and ether. Further studies are necessary to understand the effect of changes in humic acid on the nitrogen mineralization in the wetland soils. Contact Information: Fahmida Rahman, Bangladesh Rice Research Institute, Soil Science Division, Gazipur 1701, Bangladesh, Phone: 8802 9263395, Fax: 88029262734, Email: [email protected]


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Biogeochemistry of Wetland Soils: A Review of Five Decades of Research K. R. Reddy1 and R. D. Delaune2

1Wetland Biogeochemistry Laboratory; Soil and Water Science Department, University of Florida, Gainesville, FL

2Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA Wetland biogeochemistry is an interdisciplinary science that includes the study of physical, chemical, and biological processes, as related to the functions and values of wetland ecosystems. The fundamental framework for much of the wetland biogeochemistry research was provided by the basic research conducted on flooded rice soils. Dr. William H. Patrick was one of the few scientists in the world initiated research to study physical, chemical, and biological processes of flooded rice soils, as related to plant nutrition. About five decades ago, Dr. Patrick initiated his research on Crowley silt loam, a soil predominantly used for rice culture in Louisiana and Arkansas, to study the concentration and movement of oxygen as related absorption of ammonium and nitrate by rice. During the next four decades, a number of studies were conducted by Dr. Patrick and his students and associates, to determine the influence of soil oxidation-reduction potential on the fate of various nutrients, metals, and toxic organics in flooded soils, using flooded Crowley silt loam as a ‘model’ soil. The concepts and techniques developed using this ‘model’ soil were used to study the fate of nutrients, metals, and organics in wetland, as related to ecosystem functions. In this paper I will review key findings of the research conducted on flooded Crowley silt loam soil and discuss the relevance of this research to our current understanding of wetland biogoechemistry. Contact Information: Ramesh Reddy, University of Florida, Soil and Water Science Department, 106 Newell Hall, P.O.Box. 110510, Gainesville, FL 32611-0510 USA, Phone: 352-392-1804 ext. 317, Fax: 352-392-3399, Email: [email protected]


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Wetland Macrophyte Decomposition under Different Nutrient Conditions: What Is More Important, Litter Quality or Site Quality? Eliška Rejmánková1, Dagmara Sirová2 and Kateřina Houdková2

1University of California Davis, One Shields Ave., Davis, CA USA 2Faculty of Biological Sciences, University of South Bohemia, České Budějovice, Czech Republic

Plants in nutrient poor environments are often characterized by high nutrient resorption resulting in poor litter quality and, consequently, slow decomposition. We used oligotrophic, P-limited marshes of northern Belize as a model system, on which to document and explain how changes in nutrient content along a salinity gradient affect decomposition rates of macrophytes. In 2001 we established a nutrient addition experiment (P, N, and N&P) in fifteen marshes of a wide range of water conductivities (200-6000 μS), dominated by Eleocharis spp. To determine what is more important for decomposition, the initial litter quality, or site differences, we used reciprocal litter placement and cellulose decomposition assay in a combined “site quality” and “litter quality” experiment. In order to get a better understanding the role of extracellular enzymes in decomposition processes, we examined the activities of four extracellular enzymes: alkaline phosphates, leucine-aminopeptidase, β-glucosidase and arylsulphatase that play principal roles in the cycling of P, N, C and S, respectively. Our prediction of the positive effects of P-enrichment on decomposition rate due to both the quality of litter and the site was confirmed. The site effect was stronger than the litter quality although both were highly significant. Strong site quality effect was apparently the result of more active decomposer community in P-enriched plots as supported by finding of higher microbial biomass in litter decomposing in those plots. The strong effect of site quality on decomposition was further confirmed by the cellulose assay. The cellulose decomposition proceeded significantly slower at high salinity sites. This indicates that decomposer microbial activity may be lower in high salinity marshes. Litter nutrient N and P content and nutrient ratios were well correlated with decomposition with the best fit found for log C/P. At C/P ratio of >4000 decomposition processes were extremely slow. Alkaline phosphatase was most active in the decomposing material from P-deficient plots, while the other three enzymes exhibited 2 to 3x higher activity in the decomposing material from +P and +N&P plots. As with the decomposition rate, the effect of site on the enzymatic activities was highly significant while the initial litter quality was either less significant (leucine-aminopeptidase and arylsulphatase), or non significant (phosphatase and β-glucosidase). Nutrient, specifically P, addition into oligotrophic wetlands results in higher primary production, but also changes in nutrient composition and microbial environment. Both litter quality and site environment have significant effect on decomposition and results from reciprocally placed litter bags indicate a stronger effect of site than the litter quality. Contact Information: Eliška Rejmánková, University of California Davis, Department of Environmental Science and Policy, One Shields Ave., Davis, CA 95616, USA, Phone: 530 752 5433, Fax: 530 752 3350, Email: [email protected]


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Chemical Speciation of Phosphorus as an Index of Alterations in Ecosystem Structure and Function Curtis J. Richardson1, P. V. Sundareshwar2 , Wyatt H. Hartman2 and Greg. L. Bruland3

1Duke University Wetland Center, Nicholas School of the Environment and Earth Sciences, Durham, NC 2Institute of Atmospheric Sciences, South Dakota School of Mines, Rapid City, SD 3University of Florida, Soil and Water Science Department, Institute of Food and Agricultural Sciences,

Gainesville, FL Over the past 50 years phosphorus studies in wetlands and lakes have mainly focused on total phosphorus (TDP) and various species of available phosphorus (SRP), with an emphasis on the mechanisms controlling the release and recycling of these forms of P. However, inorganic and organic soluble unreactive phosphorus forms (Inositol phosphates Phosphonates (C-P), sugar phosphates, mononucleotides, nucleic acids (DNA, RNA) phospholipids, aromatic phosphates etc.) make up a significant portion of TDP in ecosystems, some are bioavailable, but relatively understudied. Modern 31P NMR techniques allow us to determine the chemical forms of P that previously were not quantified in the environment. This approach can serve as a marker for anthropogenic impact changes in land use, as well as provide a indicator of P chemical diversity declines with ‘habitat destruction’. Moreover, we present evidence that P chemical speciation quantification provides a link between biological diversity and ecosystem function. This may provide a powerful new tool to estimate the progress of wetland ecosystem restoration efforts. Case study examples from different age wetland restoration sites as well as examples of changes along phosphorus nutrient gradients will be presented. Contact Information: Curtis J. Richardson, Duke University Wetland Center, Nicholas School of the Environment and Earth Sciences, Levine Science Building, Durham North Carolina 27708, Phone: 919-613-8006, Fax: 919-613-8101, Email: [email protected]


91

Phosphorus, Patrick and Polemics Curtis J. Richardson

Duke University Wetland Center, Nicholas School of the Environment and Earth Sciences, Durham, NC While phosphorus is often consider a nonvolatile element in biogeochemical terms it surely is not in the world of environmental politics and the law. During the past 30 years I have researched both biotic and abiotic mechanisms of P transformations as well as the factors controlling storage and losses from wetland ecosystems. What is not know is that most of these studies represented a 3 decade long interaction with William Patrick Jr. on important issues related to phosphorus on a both national and state level. This presentation will highlight how some of Patrick’s early research and advise inspired my research approach concerning the mechanism controlling removal of P from wastewater in wetlands (Houghton Lake Michigan) in the 1970’s. In the 80’s Bill and I worked together on phosphate mining in wetland areas in the Peace River of Florida and the lessons learned there proved invaluable when we worked together on Florida Everglades issues in 1990’s.

Contact Information: Curtis J. Richardson, Duke University Wetland Center, Nicholas School of the Environment and Earth Sciences, Levine Science Building, Durham North Carolina 27708, Phone: 919-613-8006, Fax: 919-613-8101, Email: [email protected]


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Pelagic and Benthic Nutrient Conversions in a Coastal Watershed Influenced by River Diversions (Caernarvon, Louisiana) J. J. Rick1, S. Rick1 and R. R. Twilley2

1University of Louisiana at Lafayette, Department of Biology, Lafayette, LA, USA 2Louisiana State University, Department of Oceanography and Coastal Science, Wetland Biogeochemistry

Institute, Baton Rouge, LA, USA Mississippi water is discharged into the Breton Sound at the Caernarvon diversion (south of New Orleans) in a pulsed pattern from winter to late spring. The function of wetland soils as nutrient sinks in response to the input of the eutrophic river water was assessed from 2001 to 2004 through several seasons. Nutrient fluxes and denitrification rates were measured in incubated non-vegetated sediment cores from three main stations located in increasing distance from the diversion structure. Strong seasonal variability was observed, with potentially very high fluxes of nitrate into the sediments during summer. Regional differences were strongly influenced by ambient dissolved inorganic nutrient concentrations, temperature, carbon supply, and the distribution of benthic organisms. During diversion events in spring 2003 and 2004 pelagic and benthic nutrient cycling measured in parallel for the main stations. In both years the pelagic nutrient conversion was in the same or even higher range as the benthic uptake. This data will later be combined with other data established within the ongoing interdisciplinary project NUMAN (“Utilizing Mississippi River Diversions for Nutrient Management in a Louisiana Coastal Watershed”) to improve nutrient budgeting models for the region. Contact Information: J. J. Rick, University of Louisiana at Lafayette, Department of Biology, 300 East St. Mary Blvd., Lafayette, LA 70504, USA, Phone: (337) 482 6756, Fax: (337) 482 5834, Email: [email protected]


93

The Use of Mangrove Forests to Treat Shrimp Ponds Effluents in the Neotropics: Current Issues and Viability V. H. Rivera-Monroy1, D. Gauthier 2, R. R. Twilley1, J. W. Day3, E. Castaneda1 and H. Corrales2

1Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana USA 2Granjas Marinas San Bernardo, Choluteca, Honduras 3Coastal Ecology Institute, Department of Oceanography and Coastal Sciences, Louisiana State University, Baton

Rouge, Louisiana USA Coastal water quality is critical in shrimp farming since shrimp pond management operations requires large volumes of brackish water to assure optimal conditions for shrimp survival and growth, particularly in semi-intensive shrimp farming. The carrying capacity of an estuary can be defined as the level of waste-loading that it can assimilate without degrading water quality below a level deemed acceptable. A reduction in environmental quality of the estuary can have a negative feedback effect on shrimp pond operations. Recent studies in Honduras show that effluent loadings are in the range of 35 kg of nitrogen (N) and 12 kg of phosphorous (P) for 1000 kg of live shrimp produced. Our estimates from shrimp farms in Colombia indicated a loading rate range of 34-74 kg ha-1 yr-1 for inorganic N. In Asia, low density of shrimp operations produce loadings of 455 and 328 kg of N and P, respectively, per 1 ton of shrimp produced. The overall impact of these organic and inorganic loadings on the productivity of the receiving waters is not clear, mainly due to the variety and complexity of the interaction of physical and biogeochemical factors regulating the uptake and recycling of nutrients in the estuary. Nutrient enrichment of estuarine waters include several effects such as: a) eutrophication of adjacent estuaries, b) increased sedimentation due to organic matter accumulation, and c) reduced dissolved oxygen in receiving waters. The use of mangrove wetlands in tropical regions to treat effluents from shrimp farming is not generally practiced, as water treatment has not been required of shrimp producers. Moreover, many shrimp aquacuaculture ponds haven constructed in or adjacent to mangrove wetlands causing the functional loss of these wetlands in the coastal zone of countries like Ecuador and Tahiland. Estimates of N and P loading from shrimp ponds into coastal waters are limited making it difficult to assess the potential use of mangrove wetlands to ameliorate nutrient inputs from pod effluents. Based on published nutrient budgets estimated for several sites in the neotropics we propose a management strategy to integrate the natural function of mangroves with the management of shrimp ponds This strategy can serve as a means of altering, what is presently a potential negative impact of intensive and semi-intensive aquaculture to estuarine tropical ecosystems, into a positive feedback. We hypothesize that the use of mangrove forests as nutrient filter of pond effluent would limit the negative feedback of shrimp ponds on the water quality of coastal ecosystems. Contact Information: Victor H. Rivera-Monroy,Wetland Biogeochemistry Institute, Department of Oceanography and Coastal Sciences, Louisiana State University, 3209 Energy, Coast & Environment Bldg., Baton Rouge, Louisiana USA 70803, Phone: (225) 578.2745, Fax: (225) 578-6423, Email: [email protected].


94

Modeling Phosphorus Dynamics in the Shark River and Taylor Sloughs, Everglades National Park Colin Saunders and Daniel L. Childers

Southeast Environmental Research Center, Florida International University, Miami, FL The Everglades is an oligotrophic wetland landscape, with phosphorus (P) limiting most ecosystem processes. Over the past 70 years, wetlands of the south Florida Everglades have experienced significant environmental changes due to natural variability and human management of hydrology, fire regimes, and nutrient loading. Recently observed changes in the structure, function, and distribution of natural plant and consumer communities are likely to have important feedbacks on P cycling and therefore water quality. The Comprehensive Everglades Restoration Plan (CERP) includes a series of ecological and hydrologic improvements to restore water quality, quantity, timing, and distribution in what is being referred to as "the largest environmental restoration project in history." Here we introduce an ecosystem model used to investigate how specific ecosystem processes affect P dynamics within Cladium-dominated (CLAD) and wet prairie-slough (WPS) communities and across the Everglades National Park (ENP) landscape. The ongoing FCE LTER provides a solid foundation for calibrating community-specific models and for linking these models into a linear, “ribbon” model simulating P dynamics from upstream, freshwater sites to the southern ecotone sites in the Shark River and Taylor Sloughs. Our first two objectives are (1) to summarize existing data on P stocks and fluxes for the two communities in Shark and Taylor Sloughs, ENP; and (2) to develop dynamic models to quantify the sensitivity of P dynamics to specific ecosystem processes. For these objectives, we use the modeling framework to explore 3 hypotheses, involving processes at different spatial scales: A. between-community: In the short-term (<3 years), non-water P stocks in CLAD are closer to steady-state compared to WPS; and on a decadal scale, CLAD communities become net sinks for P whereas WPS communities become net sources of P. B. within-community: In the short-term, water-P stocks are controlled by fast-turnover pools (flocculant matter and periphyton) in WPS but are unaffected by ecosystem processes in CLAD. Long-term dynamics are controlled by macrophyte and detritus pools in both communities and additionally by the greater trophic diversity in WPS. C. landscape-scale: On a landscape scale, the degree of sink strength for P is controlled by and proportional to the ratio of CLAD:WPS areal cover. Our third objective is to simulate P dynamics under restoration “scenarios” of increased water flow and P inputs to ENP. Our models test the hypothesis that landscape responses will depend primarily on landscape-scale variation in CLAD:WPS more than between-community and within-community variations in ecosystem processes. Contact Information: Colin J. Saunders, SERC, Florida International University, 11200 SW 8 Street, Miami, FL 33199, Phone: 305-348-7319, Fax: 305-348-4096, Email: [email protected]


95

Sediment Accretion and Long Term Sequestration of Phosphorus and Carbon in Periphyton-Dominated Stormwater Treatment Areas L. J. Scinto1, J. Haberer1 and S. Long2

1Florida International University, Southeast Environmental Research Center, Miami, FL, USA 2Professional Service Industries, Inc., Tampa, FL, USA

Phosphorus (P) is the limiting nutrient in pristine Florida Everglades. However, the system has been impacted from drainage containing high levels of P from Everglades Agricultural Areas (EAA) and the Lake Okeechobee watershed. As a rehabilitation effort, The South Florida Water Management District built several Stormwater Treatment Areas (STAs) to reduce P concentrations to natural levels (10 µg P L-1). In particular, Periphyton-Based Stormwater Treatment Areas (PSTAs) have been established as post-STA treatments to further enhance water quality. Periphyton, the dominant producer in these communities, is known to effectively remove P from enriched water through biological uptake, adsorption and co-precipitation processes. Submerged aquatic vegetation, i.e. Chara, provide a structural support network for periphyton communities. Three - 5 acre PSTA field scale cells were evaluated for efficacy of phosphorus removal. Each cell varied with regard to substrate material and flow patterns (aspect ratios) and became dominated by specific biotic components. Cell 1 was dominated by periphytized Chara, Cell 2 by metaphyton (free-floating periphytic mats), and Cell 3 by epipelic periphyton. Biotic components differed significantly in TP. Phosphorus retained per unit area varied as a function of concentration and biomass. Total P concentration (624 µg P g-1 DW) and mass per unit area TP retained (719 mg P m-2) show that periphytized Chara sequestered the most TP. High TP sequestration was due largely to the increased surface area of periphytized Chara in contact with P in overlying water. Cells were intermittently flooded for 2.4 years after which pumping was halted and cells were allowed to dry. Accumulated sediment was quantitatively sampled and analyzed for TP and total inorganic C (TIC). Greatest sediment TP and TIC sequestration was observed in Cell 1, previously dominated by periphytized Chara, averaging 3.1 ± 0.98 g TP m-2 and 1081 ± 471 g TIC m-2. Total P retained in dry sediments was highly stable. Less than 5 % of TP retained (6.47 µg P g-1 DW of 211 µg TP g-1 DW) was released to artificial marsh water in a series of 10 desorption extractions. Total P and TIC retained per time flooded (2.0 of 2.4 years) averaged 1.6 g TP m-2 y-1 and 540 g TIC m-2 y-1. Contact Information: L. J. Scinto, Florida International University, Southeast Environmental Research Center, 11200 SW 8th St, University Park, OE 148, Miami, FL 33199, Phone: 305-348-1965, Fax: 305-348-4096, Email: [email protected]


96

Enzymatic Controls on Primary Production and CNP Stoichiometry in Wetland Metaphyton J. Thad Scott and Robert D. Doyle

Center for Reservoir and Aquatic Systems Research, Department of Biology, Baylor University, Waco, TX, USA Longitudinal gradients of nutrient availability often occur along the flow path of water in freshwater wetlands. Differential removal efficiencies of water column nitrogen (N) and phosphorus (P) may increase the severity of nutrient deficiency and possibly change the nutrient that limits primary production. A previous study demonstrated that periphyton in the Lake Waco Wetlands (LWW), near Waco, Texas, USA, are generally more P limited near the inflow and become increasingly N limited as distance from the inflow increases. Therefore, spatial heterogeneity in nutrient availability likely influences both the structure and function of periphyton assemblages within this system. In this ongoing study, we are evaluating the relationships between metaphyton primary production, nitrogenase activity, alkaline phosphatase activity, and CNP stoichiometry in areas of differing nutrient limitation within the LWW. As expected, primary production is generally greatest in areas where nitrogenase and alkaline phosphatase activities are minimal. However, expected increases in C:N ratios in areas of greatest nutrient deficiency have not been frequently observed. Decreased primary production and increased enzyme mediated nutrient uptake appear to balance metaphyton nutrient content in these areas. Contact Information: J. Thad Scott, Center for Reservoir and Aquatic Systems Research, One Bear Place #97388, Waco, TX 76798, Phone: 254-710-2148, Email: [email protected]


97

A Pilot Study: Greenhouse Gas Emissions from Soils in Southeastern U.S. Forests Emily N. Sekula1, Carl C. Trettin2 and Timothy J. Callahan3

1Department of Geology and Environmental Geosciences, College of Charleston, Charleston, SC 2USDA-Forest Service, Southern Research Station, Center for Forested Wetlands Research, Charleston, SC 3Department of Geology and Environmental Geosciences, College of Charleston, Charleston, SC

Quantifying sources and sinks of greenhouse gases is important in global warming research. Other than carbon dioxide (CO2), two important trace gases are methane (CH4) and nitrous oxide (N2O). Wetlands are recognized as sinks for CO2 and sources for the majority (22.5%) of CH4. Many agricultural lands have been restored to wetlands in hopes of sequestering atmospheric carbon. Most studies have been conducted in boreal regions and show that disturbed wetlands can act as sinks for CH4. Research is needed on forested wetland greenhouse gas emissions in temperate climates. Using static chambers and gas chromatography, our purpose is to quantify CH4 and N2O effluxes in a Southeastern U.S. forest. The site is the Francis Marion National Forest, 48 km north of Charleston, South Carolina. During summer 2004, soil mesocosms (1700-cm3 in size) were constructed to develop methodology for the micro-gas chromatographer and to examine gas emissions under varied hydrologic conditions. Gases sampled from the water-saturated soil mesocosms showed an increase of CO2 and CH4 over time. Decreasing the potentiometric head in the mesocosms (and thus creating an aerobic zone) reduced CH4 gas flux. In both instances we did not detect N2O emissions from the mesocosms, yet after nitrate amendments, N2O gas was measured and the emissions rates of both CO2 and CH4 were decreased. Now that experimental protocol has been established, we are ready to deploy gas emission chambers to the forested wetland. Research will provide information in this temperate forest for comparison to restored forested wetlands in similar regions. Contact Information: Timothy Callahan, Department of Geology and Environmental Geosciences, College of Charleston, 66 George Street, Charleston, SC 29424, Phone: 843-953-5589, Fax: 843-953-5446, Email: [email protected]


98

Extracellular Enzyme Activity and Distribution in Benthic Cyanobacterial Mats: Comparison between Nutrient Enriched and Unimpacted Sites in Marshes of Northern Belize D. Sirova1, J. Vrba1,2 and E. Rejmankova3

1University of South Bohemia, Faculty of Biology, Department of Ecology, Ceske Budejovice, Czech Republic 2Hydrobiological Institute AS CR, Ceske Budejovice, Czech Republic 3University of California, Department of Environmental Science and Policy, Davis, CA, USA

Alkaline-limestone based wetlands covering extensive areas of the Yucatan peninsula are characterized by extreme conditions in terms of hydrology, nutrient availability and salinity. These harsh conditions allow the development of thick cyanobacterial mats (CBM) - complex benthic microbial communities in which cyanobacteria are the main mat building group. Mats are an important part of northern Belizean marshes, constituting a large part of biomass and primary production. In order to elucidate their role in nutrient cycling we measured the activity and distribution of four extracellular enzymes: alkaline phosphatase, leucine-aminopeptidase, β-glucosidase and arylsulphatase. These enzymes play principal roles in the cycling of phosphorus, nitrogen, carbon and sulphur respectively. Nine locations representing the range of salinity occurring in northern Belize, on which a long-term nutrient addition experiment was set up in 2001, were chosen for sampling. We aimed to determine the influence of nutrient addition and salinity on the activity of these enzymes and to asses their distribution between CBM and the underlying sediment. Measurements using fluorogenic substrates revealed that alkaline phosphatase always exhibited the highest activity, followed by leucine-aminopeptidase, arylsulphatase and β-glucosidase. The activity was localized mainly in the CBM itself and decreased with depth into the underlying sediment. Phosphorus addition caused significant decrease in phosphatase activity under all salinity levels but had no significant effect on activity of the other enzymes under study. Activity of these enzymes was not influenced by nitrogen. Alkaline phosphatase seems to be a key enzyme in this phosphorus-limited system. A detailed study using Enzyme Labelled Fluorescence was therefore performed on selected samples to visualize the vertical distribution of the enzyme as well as its distribution among various organisms within CBM. Observations under the epifluorescence microscope revealed that, within CBM, phosphatase was predominantly unassociated with cyanobacterial and bacterial cells and most of the active enzyme sites were distributed in the extracellular polysaccharide matrix of the mat. The only exception was Chroococcus and few other species of coccoidal cyanobacteria which consistently produced membrane-bound activity. The highest concentration of active enzyme sites was observed in the transitional zone between the CBM and the underlying sediment. Contact Information: D.Sirova, University of South Bohemia, Faculty of Biology, Department of Ecology, Branisovska 31, 380 01 Ceske Budejovice, Czech Republic, Phone: +420-38-7775872, E-mail: [email protected]


99

Role of Phosphorus in Assessing Ecosystem Response to Anthropogenic Impact and Global Environmental Change Studies P. V. Sundareshwar1, Eric Koepfler2 and C. J. Richardson3

1Center for Biocomplexity Studies, Institute of Atmospheric Sciences, South Dakota School of Mines and Technology, Institute of Atmospheric Sciences, Rapid City, SD

2Coastal Carolina University 3Duke University Wetland Center, Duke University, Durham, NC

Chemical speciation of phosphorus has been used to understand various ecosystems processes such as controls on primary production and decomposition processes. Here we use the information on phosphorus speciation, revealed through 31P Nuclear Magnetic Resonance (NMR) spectroscopy, to gain insights into anthropogenic impacts and progress of ecosystem restoration efforts. We show that while in the urbanized Cooper River estuary, SC, the accumulation of pyrophosphate was related to the localized intensity of high impact urban areas, 31P NMR analyses of concentrated river water and floodplain sediments in the Cape Fear River, NC, revealed that phosphorus loading in this river occurs in diverse chemical forms. In this river, riverbank sediments showed the presence of phosphorus forms such as Glyphosate (a commonly used weedkiller), Aminomethylphosphonic Acid (a degradation product of Glyphosate) and pyrophosphate (the smallest chemical form of polyphosphate with wide industrial applications), in addition to more commonly observed phosphorus forms. We will also illustrate the consequences of P enrichment for ecosystem dynamics. The role of P in global environmental change is less integrated than nitrogen (N) or carbon (C). However, evidence from a coastal marine environment suggests that C, N, and P cycles are tightly coupled, such that alterations in P availability has the potential to regulate the cycling of both N and C. Data from long-term monitoring efforts at the North Inlet estuary also suggest that N:P ratio in some coastal environments has been increasing over the past 20 years, mainly driven by a steady decline in P concentrations. There is a concomitant increase in dissolved organic carbon, likely due to reduced ability of microbial heterotrophs to utilize C, as the growth of microbes here is limited by P. Alternatively, the recent observations that P availability limits the growth of microbes, could be a function of decreasing availability of P. Although, it is yet unclear as to what is causing the long-term decline in P in this ecosystem, these data nevertheless underscore the importance of integrating the role of P in global environmental change studies. Contact Information: Dr. P. V. Sundareshwar, South Dakota School of Mines and Technology, Institute of Atmospheric Sciences, 501 East St. Joseph Street, Rapid City, SD 57701, Phone: 606-394-2492, Email: [email protected]


100

Effect of Integrated Nutrient Management on the Maintenance of Soil Fertility Under Flooded Rice Eco-System Pintu Sur and D. K. Das

Department of Agricultural Chemistry & Soil Science, Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal, India

A field experiment was conducted in a Haplaquept soil (pH, 7.70; organic carbon, 0.56 %) to study the effect of integrated nutrient management (INM) on the maintenance of soil fertility under flooded rice eco-system under different treatment combinations viz. Control, only OM (Organic manure) at 10 t/ha (T1), N:P2O5:K2O as recommended (80:40:40) + no OM (Organic manure) (T2), NPK + OM at 4 t/ha (T3), NPK + OM at 8 t/ha (T4), N at 3 splits + PK + OM at 4 t/ha (T5), N at 3 splits + PK + OM at 8 t/ha (T6), OM at 10 t/ha+ Zn at 0.5 kg/ha as Zn-EDTA (T7), OM at 4 t/ha + Zn at 0.5 kg/ha + NPK as basal (T8), OM at 10 t/ha + N in 3 splits + PK as basal (T9). The half N of total recommended + entire amount of P2O5, K2O and Zn were applied as basal and the rest amount of nitrogen were applied in two equal splits at 21 and 42 days after transplanting (DAT) of rice. The overall results show that the adoption of integrated nutrient management practices helped to build up of soil nutrient status with respect to N, P, K, Fe, Mn, Cu and Zn contents with the simultaneous increase in the yield and nutrient uptake by rice. The results suggested that the treatment T8 receiving recommended levels of N, P and K, 4 t/ha organic manures and 0.5 kg/ha Zn as Zn-EDTA was proved superior in augmenting soil fertility and quality as well as yield and nutrition of rice. However, the highest organic carbon content (0.78%) was observed in treatment T8 where 4 t/ha organic manure was applied with recommended doses of NPK and zinc at 0.5 kg/ha. The highest amount of N (442.57 kg/ha) and K (362.60 kg/ha) were observed in T8 treatment and P (18.29 kg/ha) in T9 treatment. The results further concluded that the amount of cationic micronutrients (Fe, Mn, Cu and Zn) in soil have been found to be increased with T7 and T8 treatment where OM at 4 t/ha + Zn at 0.5kg/ha as Zn-EDTA and OM at 10 t/ha + Zn at 0.5kg/ha + NPK as basal were applied respectively. Contact Information: Pintu Sur, Bidhan Chandra Krishi Viswavidyalaya, Department of Agricultural Chemistry & Soil Science, Mohanpur 741 252, Nadia, West Bengal 741 252 India, Phone: 9133 25826150, Phone 2: 910 9830316606, Fax: 9133 25828460, Email: [email protected]


101

Influence Of Freshwater Diversions And Drought On Peat and Porewater Sulfur Dynamics in Coastal Louisiana Peat Marshes C. M. Swarzenski1, T.W. Doyle2 and B. Fry3

1United States Geological Survey, Baton Rouge, LA, USA 2United States Geological Survey, Lafayette, LA, USA 3Coastal Ecology Institute, Louisiana State University, Baton Rouge, LA, USA

Freshwater peat marshes are sulfur-sensitive ecosystems. Sulfide is highly toxic to plants that dominate freshwater peat marshes. Biogeochemical reactions involving sulfur contribute to organic matter breakdown and may facilitate mercury methylation. We measured porewater sulfate and sulfide concentrations in freshwater peat marshes in coastal Louisiana, subjected to regular inflow of river water and isolated from such inflow, at four to six week intervals between August 1998 and July 2002. Sampling occurred before, during and after a severe drought lasting from late fall 1999 to autumn 2000. We also analyzed for total sulfur in the peat. Average porewater sulfide concentrations were significantly higher in marshes subjected to regular inflow of river water (16.8 uM, micromolar) than in marshes isolated from river inflow (6.5 uM), even though average and peak sulfate levels in adjacent surface water were significantly lower in these same areas. Sulfate concentrations in river water are quite low, but regular overland sheet flow of this water resulted in total sulfur in peat in excess of levels found in similar marshes without river inflow. The long-term regular inflow of river water into low-sulfur peat systems may result in elevated sulfur concentrations in the substrate and high sulfide concentrations in porewater. The extended drought precipitated a short-term response opposite to the long-term trends. Sulfides were oxidized during the drought in the marshes receiving regular inflow of river water, the result of prolonged water levels below the marsh surface. Average sulfide concentrations dropped to 13.3 uM, below the pre-drought average of 23.5 uM. Although sulfate concentrations temporarily increased in porewater, the discrete sampling did not measure a concomitant drop in pH. Even though the inflow of river water was sharply reduced during the drought, freshwater inflow was sufficient to keep seawater intrusion minimal. In contrast, the area isolated from river-water inflow experienced prolonged intrusion of more saline water, resulting in elevated sulfide concentrations during and after the drought that averaged around 7.8 uM in porewater, higher than the pre-drought average of 3.2 uM. Contact Information: C. Swarzenski, USGS, 3535 S.Sherwood Forest Blvd., Ste 120, Baton Rouge, Louisiana, USA, Phone: 225-298-5481, Email: [email protected]


102

Use of Porewater Calcium: Magnesium Ratios to Track Source Waters to, and Distinguish among Plant Communities in Coastal Louisiana Peat Marshes C. M. Swarzenski1 and T.W. Doyle2

1United States Geological Survey, Baton Rouge, Louisiana, USA 2United States Geological Survey, Lafayette, Louisiana, USA

Coastal Louisiana contains more than 150,000 hectares of freshwater peat marshes. These occur as a variety of distinct plant communities under a narrow range in salinity fluctuations. Porewater quality in these marshes is influenced by precipitation directly, through inflow of river water, and by occasional infiltration of seawater. The various water sources play a role in structuring the plant communities, and also impact the quality of the peat substrate. In this study, we explored the use of dissolved calcium and magnesium in porewater, and especially the Ca:Mg ratio, to identify sources of fresh water to the peat marshes, and in distinguishing among the different plant communities. River water has a Ca:Mg ratio of 3:1, whereas precipitation is closer to 1:1. Freshwater also contains significantly lower concentrations of calcium and magnesium than seawater. As the influence of seawater increases, the ratio decreases to less than one. Using Ca:Mg ratios, we were able to demonstrate that river water infiltrates porewaters to a depth of at least 90 cm in marshes regularly inundated by river water. Ratios were close to 3:1 to at least this depth. In fresh conditions, this ratio is an effective way to determine whether and to what extent river water infiltrates marshes, as would occur in freshwater diversions. Ca:Mg ratios were also effective at distinguishing among plant communities. Plant communities typically vary in their tolerance to sulfides and chlorides. These vary depending on the degree of mixing of freshwater and seawater. Ca:Mg ratios tracked changes in average porewater concentrations of total sulfate and sulfide among plant communities well. Ca:Mg ratios were good indicators of source waters and plant community type in freshwater peat marsh ecosystems, probably because this ratio integrated diverse hydrological factors. Inclusion of these two parameters in monitoring schemes in this environment may prove useful and cost-effective. Contact Information: C. Swarzenski, USGS, 3535 S.Sherwood Forest Blvd., Ste 120, Baton Rouge, Louisiana, USA, Tel: 225-298-5481, Email: [email protected]


103

Mercury Levels in Fish in Lake Pontchartrain M. Tan1, A. Hou1, M O'Connell2 and R. DeLaune1

1Louisiana State University, Baton Rouge, LA, USA 2University of New Orleans, New Orleans, LA, USA

UNIVERSITY OF NEW ORLEANS Mercury contamination of fish in lakes has become a public health issue in recent years since fish is a primary source of mercury exposure to humans. It has been reported that mercury from fish appears to cause neurological damage while increasing the risk of myocardial infarction (SCIENCE 301:1203, 2003). Despite the importance of Lake Pontchartrain as a source of income and food for many people in Louisiana, there has never been a lake-wide assessment of mercury levels of those fishes that occur in the estuary. We have collected fish from the five main ecological regions of the estuary and tissue samples analyzed for total mercury content over last two years. Once collected and identified, fish specimens were euthanized, weighed, measured, and wrapped individually in aluminum foil before being put on dry ice for transport to the laboratory. Once at the laboratory the fish specimens were kept frozen at -20oC until analysis. Axial muscle tissue was removed from slightly thawed fish specimens using a stainless steel scalpel. Muscle tissue samples were then homogenized and digested using an acid digestion procedure and analyzed for total mercury using a Mercury LabAnalyzer 254. Quality control methods included analysis of reference materials and blanks in each analytical batch. The paper being presented will report the mercury status of six species of fish in five ecological regions of Lake Pontchartrain.

Contact Information: MeiHuey Tan, Department of Environmental Studies, Louisiana State University, Baton Rouge, LA 70803, Phone: 225-578-4294, Fax: 225-578-4286, Email: [email protected]


104

Wintertime Stable Isotopic and Geochemical Profiles from Pore water Peepers at the Margin of an Acidic Wetland, Bear Meadows, Centre County, PA Burt Thomas and Michael Arthur

The Pennsylvania State University, Department of Geosciences, State College, PA Wetland margins lie in a transition zone between methane consuming uplands and methane producing lowlands. Steep hydrologic, pedologic, biologic and chemical gradients across wetland margins result in significant uncertainty about how these margins affect wetland methane budgets. Here we introduce methodology and report winter measurements from a transect of pore water peepers that extend from the forested edge of an acidic fen to the sphagnum dominated lawn. The wetland is bounded on 3 sides by hills of quartz-cemented sandstones and shales. The data presented here are from liquid samples collected in mid December 2004 from four pore water peepers positioned in a transect perpendicular to the wetland margin. These peepers are deployed within permanently installed outer casings so that a time-series of pore water data can be collected over several seasons. The peeper cells are designed to be used with common laboratory filters (45 mm, .2 μm polypropylene) and provide spatial resolution of 5 cm in the vertical dimension. The cells are sampled for gas analyses using gas-tight syringe additions to flushed headspace vials. The remaining cell contents are analyzed with a field-portable pH/Eh meter and frozen immediately for aqueous chemical analyses. Headspace above pore water samples are measured for dissolved methane concentrations using gas chromatography with a flame ionization detector. Dissolved concentrations are calculated from Henry’s Law relationships. The δ13C of methane was determined on headspace samples with >10 ppm CH4 with a continuous flow isotope ratio mass spectrometer. Stable carbon isotopic compositions of methane are reported relative to VPDB via an internal standard. Eh and pH profiles show an inverse relationship with depth. Constant values are observed from 0-25 cm (Eh, 650 mV and pH, 4) with the highest gradients in Eh and pH in an interval approximately 25-45cm below the water surface. Eh and pH profiles reestablish constant values below this zone (Eh, 350 mV and pH, 5.0). The trends in Eh and pH with distance from the wetland margin are primarily expressed in peeper cells below 45 cm where values of Eh and pH trend lower toward the center of the wetland. Dissolved methane concentrations range from low μM - 2mM with distinct concentration gradients that correlate with gradients in Eh. One notable observation is that none of the samples within 20 cm of the surface show significant dissolved methane concentrations. In the absence of a concentration gradient the flux of methane to the surface via diffusion is likely minimal. Carbon stable isotopic ratios of methane range between -54 to -74 o/oo with the majority of those values between -65 and -72 o/oo. In profiles, these values trend heavier toward the surface. Significant methanotrophy in upper horizons would be consistent with the observed trends in δ13 CH4 profiles. Contact Information: Burt Thomas, 801 Deike Building, Penn State University, University Park, PA 16802, Phone: (814) 865-1178, Email: [email protected]


105

Nutrient Cycling in Indian River Lagoon Marsh Impoundments: Using Ecological Network Analysis to Determine Effects of Management Cassondra R. Thomas

NASA, Kennedy Space Center, FL The salt marshes of the Indian River Lagoon have been heavily impacted by management techniques. In the 1950s and 1960s over 75% of the wetlands were impounded for mosquito control. In the early 1990s, the marshes of the Merritt Island National Wildlife Refuge (MINWR) had culverts installed into the earthen dikes to reintroduce lagoon water flow in a controlled manner. Four management protocols are currently employed; Wildlife/Aquatic Management (WAM) impoundments are continually flooded to encourage migratory bird usage; Rotational Impoundment Management (RIM) impoundments are flooded during mosquito breeding season and open to the lagoon the remainder of the year; Open Impoundments are connected to the lagoon year round through culverts; and Restored impoundments are connects to the lagoon year round through tidal creeks. The four management techniques employed at MINWR produce very different environmental conditions among the marshes. The differing hydroperiods for these marshes create different sediment conditions that greatly influence nutrient cycling. The nutrient cycles of these marshes was analyzed with Ecological Network Analysis (ENA). Ecological network analysis is a tool for evaluating the network and assessing ecosystem level functioning. It is a collection of algorithms of model analysis to evaluate flow and cycling of energy or material through ecosystem networks and index the ‘structure’ of the networks. A model template composed of 51 compartments representing the plant, animal, and abiotic components of the marsh/lagoon ecosystem was used to create carbon, nitrogen, and phosphorus cycling models for the different impoundment types. Nutrient cycling differs between marsh types and nutrient types. Nitrogen cycling in very high in all marsh types (FCI is 70-90%) which is atypical for Atlantic coast salt marshes. Phosphorus cycling is much higher in the WAM impoundments than the other impoundment types. Overall, WAM has higher nutrient cycling than the other marshes, which is consistent with its isolation from the lagoon. Organic matter accumulation only occurs in the WAM and Open impoundments. A significant portion of the nitrogen and phosphorus sequestered in organic matter in the Open impoundments originated from lagoonal sources. A negligible amount of nutrients is brought into the marshes or removed from the marshes by migratory birds. Fiddler crabs play in increasingly important role in providing nitrogen to emergent vegetation as the impoundments get progressively drier. These results suggest that the management protocols employed at the MINWR are impacting how nutrients are cycling through the impoundments. This affects the structure and function of these marshes and their ability to handle perturbations. Contact Information: C. R. Thomas, NASA, DYN-2, Kennedy Space Center, FL 32899, Phone: (321) 476-4118, Fax: (321) 853-2939, Email: [email protected]


106

Organic Matter Mineralization: Terminal Anaerobic Steps in Tropical Wetlands R. Torres-Alvarado1, F. J. Fernández2, V. H. Rivera-Monroy3, L. G. Calva-Benítez1 and F. Ramírez-Vives2

1 Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Hidrobiología, Mexico City, Mexico 2 Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biotecnología, Mexico City, Mexico 3 Louisiana State University, Wetland Biogeochemistry Institute, Department of Oceanography and Coastal

Sciences, Baton Rouge, Louisiana, USA The abundance and activity of sulfate reducing and methanogenic bacteria was evaluated in sediments of two coastal lagoons (Chantuto-Panzacola and Carretas-Pereyra, Chiapas), located in the Pacific coast of Mexico to analyze the terminal anaerobic steps of carbon cycling and its relation with sediment environmental parameters in tropical environments. Sediment cores were collected during the dry (February, May and June) and wet (July, October and November) seasons (2002-2003), at two depths. The sulfate and methanogenic bacteria densities were measured by MPN in selective media with, several substrates. The activity was estimated using extracted sediments incubated in Balch’s media, with two substrates (hydrogen and acetate, 20 mM), and two sulfate (20 mM) treatments (with and without). Sulfate reducing and methanogenic bacteria counts were higher (101-1013 cell/cm3 of sulfate reducing bacteria and 103-1013 cell/g dry sediment of methanogenic bacteria) that those reported for marsh sediments in temperate latitudes (103-107 cell/cm3 of sulfate reducing bacteria and 103-106 cell/g dry sediment of methanogenic bacteria). During the first days of incubation in kinetic activity experiments, the appearance of acetate and others volatile organic fatty acids (propionate and butirate), reflected the hydrolysis and fermentation processes in the sediments. The specific activity measured in the Pereyra and Campon lagoons was higher in the dry season, while in the Bobo and Cerritos lagoons the activity was higher during the wet season. The specific activity increased with the presence of sulfate in the media. Hydrogen sulfide production and methane production started on the second and fifteenth days of incubation, respectively. The spatial and seasonal variations in the activity and abundance of the sulfate reducing and methanogenic bacteria appeared to be influenced by sediment environmental parameters such as salinity, sulfate, and volatile suspend solids concentrations. A conceptual model is proposed to explain the terminal anaerobic steps in the organic matter mineralization in this coastal tropical sediments. Contact Information: R. Torres-Alvarado, Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Hidrobiología, Lab. Ecosistemas Costeros (AS-224), Av. San Rafael Atlixco # 186, Col. Vicentina, 09340 Mexico City, Mexico, Phone: (55) 5804 4745, Fax: (55) 5804 4737, Email: [email protected]


107

Coupling Oligotrophy and Peat Development in a Coastal Freshwater Swamp of Panamá T. Troxler-Gann and D. Childers

Florida International University, Department of Biological Sciences and Southeast Environmental Research Center, Miami, FL

Coastal freshwater swamps are widely distributed throughout the tropics, and often characterize the freshwater end-member of coastal landscapes. Anthropogenic activities deteriorate their ecological functions of providing species habitat, regulating water quality, and contributing to global carbon sequestration. Studies of nutrient limitation in coastal freshwater swamps may indicate how changes in nutrient status affect the structure and ecological function of coastal freshwater swamps. In the Changuinola mire, a large peat deposit located in coastal Panamá, we tested the hypothesis that oligotrophy increased along a gradient of peat development (peat doming). We characterized phosphorus, nitrogen, and carbon content of tissue, soil, and soil porewater of five previously described vegetation communities along this peat development gradient. We found a significant increase in soil P concentrations and soil N:P ratios suggesting a natural gradient from N limitation to P limitation with increased peat development. Differences in plant assemblages along this gradient suggested that species could persist in: 1) high to moderately high nutrient environments that restricted their range; or 2) moderately high to low nutrient environments and expressed traits which permitted a greater distribution of these species along the nutrient gradient. However, species found from moderately high to low nutrient environments persisted without any change in their nutrient resorption efficiency. All species had higher P than N resorption efficiency despite location along the soil nutrient gradient. When interspecific variation among canopy species was reduced (averaging nutrient values for all species for each transect location), soil N:P was the single best predictor of leaf N:P ratios. Interspecific variation among canopy species demonstrated that soil N was not distributed linearly along the soil nutrient gradient, yet was a good predictor of leaf P concentrations. These results demonstrate the complex nature of nutrient limitation in coastal freshwater swamps. Yet, P limitation was clearly indicated with increased peat development and doming, and is likely associated with ombrotrophic conditions that developed as hydrologic inputs became dominated by precipitation. As ombrotophic bogs can be important groundwater recharge systems, and may have important linkages with the regional hydrology of the coastal landscape, the conservation of this coastal freshwater swamp and interior bog-plain may help maintain downstream water quality. Extensive floodplains similar to that of coastal Panama are common along the Caribbean coast, are suggested to occur in many coastal areas worldwide, and may have important functions contributing to water quality in coastal areas dominated by near-shore coral reefs. Contact information: T. Troxler-Gann, Florida International University, Department of Biological Sciences, OE 167, 11200 SW 8th St., Miami, FL, 33199, Phone: 305-348-1576; Fax: 305-348-4096; Email: [email protected]


108

Greenhouse Gases and Experiences with Bill Patrick O. Van Cleemput and P. Boeckx

Laboratory of Applied Physical chemistry (ISOFYS), Faculty of Bioscience Engineering, Ghent University, Belgium

In the sixties and early seventies, denitrification in soil was considered a negative N-transformation process; because it resulted in an economic loss of plant available N. Soon, however, the economic aspect was overshadowed by the link of denitrification with emission of harmful gaseous N-compounds. At that time not every body was even convinced of the effect of these gases on our climate. The research, initiated and further developed by Bill Patrick, first at the Agronomy Department and later at the Wetland Biogeochemistry Institute of the Louisiana State University followed the same evolution. It started with studies on conditions of nitrate and nitrite reduction in paddy soils, continued with experiments on identification of nitrate and nitrite decomposition compounds (e.g. N2O) and arrived at studies on complex interactions between greenhouse gases, up to the study of mitigation actions to lower the emission of greenhouse gases, mainly in wetlands and paddy soils. Systems carefully controlling pH and redox potential allowed the study of greenhouse gases at different aeration levels. It was found that decreasing redox potential resulted in an almost linear increase of the nitrate reduction rate. Molecular nitrogen, N2O and traces of NO were found. Mercuric chloride as well as gamma irradiation have been used to separate chemical from biological processes responsible for the N transformation processes. Mass spectrometry was used to identify formed N-compounds. The use of microcosms and gas chromatography allowed further examination of factors influencing the emission of also CH4, formed under restricted aeration. Paddy fields as well as flooded areas and wetlands were quickly identified as ecosystems producing large amounts of N2O and CH4. Studies on the interaction between nitrification and denitrification gradually shifted towards interaction between emission of N2O and CH4 from flooded soils, mainly rice paddies. Both gases are emitted at different soil redox potential conditions, allowing searching for a critical redox potential with minimal formation of both gases, as such mitigating the cumulative global warming potential. Organic matter as electron donor could easily regulate the aeration status of soils. It was found that the best management practice for low greenhouse gas emission is to keep rice fields non flooded but wet with organic matter addition. Under these conditions the global warming potential can be largely reduced with no decrease in rice yield. For several decades the use of carefully controlled pH-Eh microcosms was extremely helpful to unravel complex N-transformation processes and their interaction with the carbon cycle, thanks to the brilliant ideas of Bill Patrick. Contact Information: O. van Cleemput and P. Boeckx, Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical chemistry, Coupure 653, B-9000 Gent, Belgium, Phone: +32 9 2646002, Fax: +32 9 2646242, Email: [email protected]


109

Wetlands and Water Quality: A Landscape Perspective J. T. A. Verhoeven1, B. Arheimer2, Chengqing Yin3 and M. M. Hefting1

1Landscape Ecology, Utrecht University, The Netherlands 2Swedish Meteorological and Hydrological Institute, Stockholm, Sweden 3Chinese Academy of Science, Beijing, PR China

Wetlands are being used around the world to reduce concentrations of nutrients in through-flowing water. Many studies at the site scale have demonstrated that wetlands have a good and durable capacity to improve water quality. The scientific evidence that wetlands generally perform this function has resulted in a large number of initiatives to restore or even create wetlands in the landscape for this particular purpose. In many cases, the conservation or restoration of habitat for plant and animal species is seen as an additional benefit of such initiatives. Recent studies at longer time scales and larger spatial scales have, however, shown that there are also various environmental risks associated with nutrient loading of wetlands, which may affect regional biodiversity and global warming. It has become evident that (1) wetlands loaded beyond a critical level may drastically change in structure and functioning and may lose characteristic species; (2) in highly loaded wetlands, nutrient removal is often accompanied by substantial gaseous emissions of the greenhouse gas nitrous oxide and (3) wetland types most effective for water quality improvement are least interesting in terms of natural habitat. A further complicating factor is that many wetlands have become reduced in area and hydrologically altered, so that their natural connections with groundwater and surface water have been disrupted. This has marginalized their potential functioning as buffers in the landscape. The mere factor of wetland area in relation to catchment area is extremely important, as is shown by some striking examples. A recent study of Chinese so-called ‘multi-pond’ systems has shown that water quality is very effectively improved by a system of connected small wetlands. These systems have existed since 2000 years and can thus be considered to be robust, provided that they cover at least 8% of the total catchment area. A study of large agricultural catchments in Sweden has shown that in the current situation where streamside wetlands only covered 0.5% of the catchment area, these wetlands did not contribute to nitrogen reduction in streams. A modeling study showed that wetlands would have to amount to 5-10% of the total catchment area in order to significantly reduce nitrogen loadings towards the Baltic Sea. This paper will review recent information on critical nutrient loading rates for wetlands with respect to plant diversity and greenhouse gas emissions and discuss the spatial and temporal conditions that must be fulfilled for wetlands to be effective for nutrient reduction at the catchment scale. Contact Information: Jos T.A. Verhoeven, Landscape Ecology, Utrecht University, P.O. Box 80084, 3508 TB Utrecht, The Netherlands. Email: [email protected]


110

The Biodiversity of Lake Victoria Wetlands: Case Study of the Giant Yala Swamp, Nyando and Sondu-Miriu Wetlands, Kenya John Vorster1 and Judith Akinyi Omollo2

1Research Assistant, VIRED Int’l, Kisumu, Kenya 2Environmental Educator, C/O Yago Primary School, Suna-Migori, Kenya

The freshwater ecosystems around Lake Victoria which is the second largest freshwater lake in the world are quite diverse and form different ecological niches or habitats for the lake's rich species diversity. The study here focuses on three major freshwater wetlands on the Kenyan part of Lake Victoria, Yala Swamp, Nyando and Sondu-Miriu wetlands. Yala Swamp is the largest Swamp in Kenya part of Lake Victoria with a composition of a bout 90 % papyrus. The main species here are Cyperus papyrus and phragmitis mauritius. Of particular interest is the satellite Lake Kanyaboli which is considered to be one of the most important within Lake Victoria’s catchments. Lake Kanyaboli supports a lucrative fishery with a unique fish fauna. The lake and the adjoining giant Yala Swamp provides suitable habitat for various endangered animal species. On contrary, the Yala Swamp was reclaimed in the early 1970’s for agricultural purposes which later changed the ecological balance. The second part of the paper will give an in-depth study on Rivers Nyando and Sondu-Miriu wetlands which are draining their waters into Lake Victoria. The study will focus on the large scale agricultural activities on the upper river catchments and the agro-based chemical and sugar industries which are discharging their effluents directly into the river channel. Downstream at the river mouths, the problem is rather compounded by the destruction of wetlands resulting in high levels of nutrients entering Lake Victoria. The situation over these wetlands study sites call for an immediate attention to restore their lost glory. Yala River formerly flowed through reclaimed swamp into Lake Kanyaboli, then into the Swamp before finally into Lake Victoria via a small gulf. After the diversion of the River flow into the Swamp, and heavy siltation dike cuts off Lake Kanyaboli, which receives its water from the catchment and through back-seepage from the Swamp. The quality of water in the main channel is well oxygenated, but oxygen levels in the stagnant parts of the Swamp are very low and turbid. Biodiversity value of the Giant Yala Swamp should be recognized by affording the site some formal protection, such as listing as a wetland of international importance. This is due to the fact that Yala Swamp is a type of wetland that supports an appreciable assemblage of threatened and endemic species. The main threats to these two wetlands are agricultural intensification, burning of vegetation, construct ruction of dykes/dams and drainage. In summary the paper will give evidence to the extent that freshwater ecosystems when scored on the area they cover and a diverse species they harbour, are indeed the most species-diverse habitats on earth. Ecosystems provide an estimated US$ 33 trillion per annum to societies of which an estimated 26% comes from the precious freshwater ecosystems. Literally, wetlands suffer from over-extraction of freshwater, overuse of their resources, drainage and pollution. The degradation of wetlands puts the local livelihoods and the biological diversity at risk. Over 800 freshwater wetlands species around the world are now threatened with extinction. Contact Information: John Vorster, Research Assistant, VIRED Int’l, P.O. Box 1841, Kisumu, Kenya, Email:[email protected]


111

Heavy Metals in Phragmites australis and Phalaris arundinacea Growing in Constructed Wetlands Treating Municipal Sewage J. Vymazal1, J. Svehla2 and V. Chrastny2

1ENKI o.p.s, Trebon, Czech Republic 2University of South Bohemia, Department of Chemistry, Ceske Budejovice, Czech Republic

Constructed wetlands with horizontal subsurface flow designed for the treatment of municipal sewage have been monitored extensively with respect to removal of organics (BOD5, COD), suspended solids, nutrients (N, P) and microbial pollution. However, the information on the removal and distribution of heavy metals in these systems is limited. Due to toxic, persistent, bio-accumulative and synergistic effects of many metals on various forms of biota, their cycling, retention and fate in the environment are of great concern. Heavy and other metals do not constitute a major problem in municipal wastewaters but the question of heavy metals could be important should disposal of plants or sediments be required. The purpose of this study was to evaluate retention of 16 metals in Phragmites australis (Common reed ) and Phalaris arundinacea (Reed canary-grass) in sub-surface horizontal flow constructed wetland at Morina near Prague, Czech Republic. Constructed wetland (CW) at Morina is designed for secondary treatment of sewage and stormwater from 700 PE (population equivalent), respectively. The total area of vegetated beds is 3520 m2. Substrate is crushed rock (fraction 4-8 mm) and Phragmites and Phalaris are planted in bands perpendicular to wastewater flow. Samples of water were taken from vegetated beds inflow and outflow during 2002 on a monthly basis and analyzed for Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se, Sn, V and Zn. Aboveground biomass of both species was harvested and analyzed for metals in July and September and standing litter was also harvested in March 2003. Biomass was separated into leaves (including leaf sheaths), stems and inflorescence. Belowground biomass was sampled in July. The concentration of several metals was under the detection limit both in inflowing and discharged water and therefore, the annual budget could not be calculated for these metals. The major findings could be summarized as follows: - Concentrations of metals in various parts of both plants varied during the year. For most metals the highest concentrations occurred in the standing litter in the spring. - The concentration of metals decreased in the order roots > leaves > stems with root concentrations being about one order of magnitude higher than those in leaves and stems. - The amount of metals retained in aboveground parts of plants formed only a small fraction of the inflow - usually less than 10% and often less than 1%. - The highest retention of metals in aboveground biomass per square meter (standing stock) occurred for iron, aluminium, manganese, zinc, copper and nickel while the lowest amounts were recorded for vanadium, cadmium and mercury. Contact Information: Jan Vymazal, ENKI o.p.s, Dukelska 145, 379 01 Trebon, Czech Republic and Ricanova 40, 169 00 Praha 6, Czech Republic, Phone: +420 233 350 180, Email: [email protected]


112

Performance of Stormwater Treatment Wetlands Receiving Low Phosphorus Agricultural Drainage Water: Implications for Design and Management John R. White1, K. Ramesh Reddy2 and Jana.Majer Newman3

1Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA 2Soil and Water Science Department, University of Florida, Gainesville, FL 3Everglades Division, South Florida Water Management District, West Palm Beach, FL

Historic phosphorus (P) loading from agricultural areas has been identified as one of the major causes for ecological changes occurring in the northern Florida Everglades. The restoration plan for the Everglades included construction of large stormwater treatment areas (STAs) located between the Everglade Agricultural Area and the Northern Everglades in order to intercept and treat this relatively high nutrient water down to very low total P (< 0.050 mg P L-1) concentrations. While a number of technologies have been investigated including chemical amendments, “green” technologies are preferred due to lower cost and impact. Therefore, the ability of emergent (EAV) and submerged aquatic plants (SAV) on reducing total P concentrations was investigated in mesocosms. Reductions were calculated for the three components which comprise total P; soluble reactive P (SRP); dissolved organic P (DOP) and particulate P (PP). The effect of periodic drawdown on P reduction was evaluated for each of the plant type treatments and the two inflow concentrations of total P; 0.120 mg L-1 which represented the surface water at the inflow region of the STA and 0.023 mg L-1 which is typical of surface water proximal to the outflow regions of STA-1W. Reductions in total P for the higher concentration water (0.120 mg L-1) ranged from 71% for the drawdown treatments and 81% for the continuously flooded treatment, regardless of plant type. The SRP values were reduced by > 80% in all treatments while the DOP was reduced by an average of 17% in the continuously flooded treatment while there was a net export of DOP in the drawdown treatments. There was no significant difference with respect to particulate P at 75% reduction. In the treatments subjected to the low total P surface water (0.023 mg L-1), total P was reduced by a mean of 44.9 % in the SAV treatments regardless of hydrology while the EAV vegetation treatments were significantly lower at 34.7%. There was a significant reduction of DOP in the continuously flooded SAV treatment at 41.2 % vs. a mean reduction of 15.5% for the other 3 treatments. There was no significant reduction of PP with a mean of 43 %. These results suggest that the most effective management for P removal would focus on maintaining wet conditions, regardless of vegetation type in the front end of these systems. Vegetation management would be best focused on the regions proximal to the outflow, seeking to exclude EAV in favor of SAV due to the significantly better performance on P removal associated with SAV in this mesocosms study. Future research should focus on the generally poor removal of DOP in these systems in order to further reduce the P concentrations entering the Florida Everglades. Contact Information: John R. White, Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA 70803, Phone: 225-578-8792, Email: [email protected]


113

The Practice and the Conception for Treating the Polluted Water by Using the Natural Wetlands Wu Xiangde and Aolei Qiu

L’Association du Marécage au Cameroun In the past, many essays and experiences were tried in using the natural wetlands in the purification process of the polluted water. However, concerning the project for purifying the polluted river with natural wetlands, how effective is the capacity of the wetlands in purifying the polluted water? To attain a result comparable to that by using the equipments in a sewage treatment plant, how big should the area of wetlands be and what are the construction cost as well as the daily project maintenance cost for treating a ton of wastewater? For a long time, wetlands specialists, wetlands workers and volunteers have been searching a precise answer to the series of interrogations above. In 2003, we utilized the natural wetlands to successfully treat a polluted river in the Yaounde, Cameroon. As a result, the heavily polluted Yaounde Lake turned to be clean and fresh water. Here, starting from two domains: scientific research and the practice, we would like to share our experience with you. Following the path of the United Nations Environment Program, UNEP, which is to treat the polluted water with the ecology of the wetlands, we have come to 3 conclusions. For treating the domestic sewage by using the natural wetlands:

Six to Ten square meters of wetlands is needed for treating per ton wastewater;

The construction cost is less than 10 USD for treating per ton wastewater;

The project maintenance cost is less than 0.01 USD for treating per ton wastewater per day. Contact Information: Xiangde Wu, L’Association du Marécage au Cameroun, Auto control, P.O. box 7638, Yaounde, Cameroon, Phone: 00237-7077593, Fax: 00237-2222431, Email: [email protected]; [email protected]


114

Nitrogen Removal of a Large River Swamp System -- The Atchafalaya River Basin Y. Jun Xu

School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA, USA Nitrogen enrichment from the upper Mississippi River Basin has been attributed to be the major cause for the hypoxia in the Northern Gulf of Mexico. The hypoxia threatens not only the aquatic ecosystem health but Louisiana’s fishery industry directly among other problems. Although fresh water diversion from the lower Mississippi River into the region’s wetlands has been considered an alternative means for reducing nitrogen loading, it is largely uncertain how much nitrogen can actually be retained from the overflowing waters in these natural wetlands. Generally, there is a knowledge gap in what tools are available for accurate assessment of nitrogen inflow, outflow and removal potential for the complex and diverse coastal floodplain systems. This study is to seek answers to three critical questions: (1) Does the Atchafalaya River Swamp remove a significant amount of nitrogen from the overflowing water or release more nitrogen into the Gulf than removing it? (2) How seasonally and annually do the nitrogen removal or release rates fluctuate? (3) What are the relationships between the nitrogen removal capacity and the basin’s hydrologic conditions such as river stage and discharge? By utilizing river’s long-term discharge and water quality data (1978-2002), monthly and annual nitrogen fluxes were quantified, and their relationships with the basin’s hydrologic conditions were investigated. A total Kjeldahl nitrogen (TKN) mass input-output balance between the upstream (Simmesport) and downstream (Morgan City and Wax Lake Outlet) locations was established to examine the organic nitrogen removal potential for this largest freshwater swamp basin in North America. The results showed that on average, TKN input into the Atchafalaya was 200,323 tons yr-1 and TKN output leaving the basin was 145,917 tons yr-1, resulting in a 27% removal rate of nitrogen. Monthly nitrogen input and output in the basin were highest from March to June (input vs. output: 25,000 vs. 18,000 tons mon-1) and lowest from August to November (8,000 vs. 6,000 tons mon-1). There was a large variation in both annual and inter-annual nitrogen removals, and the variability was positively correlated with the amount of inflow water at Simmesport. However, no close relationship between the river inflow and percentage nitrogen removal rate was found. The results gained from this study suggest that regulating the river’s inflow will help reduce nitrogen loading of the Mississippi River to the Gulf of Mexico. The in-stream loss of nitrogen indicates that previous studies may have overestimated nitrogen discharge from the Mississippi-Atchafalaya River system. Furthermore, the study found that knowledge on spatial hydrological conditions in the basin is needed to understand nitrogen dynamics in the Atchafalaya River Swamp. Contact Information: Y. Jun Xu, School of Renewable Natural Resources, Louisiana State University Agricultural Center, 227 RNR Bldg., Baton Rouge, LA 70803, USA, Phone: +1-225-578-4168, Fax: +1-225-578-4227, Email: [email protected]


115

Reconstruction of Historical Mangroves in South Florida Coastal Areas through a Biomarker Approach Yunping Xu and R. Jaffé

Environmental Geochemistry Laboratory, Southeast Environmental Research Center (SERC) and Department of Chemistry & Biochemistry, Florida International University, Miami, FL USA

Mangroves are very important ecosystems in coastal areas which form habitat for a large number of species and protect against coastal erosion. South Florida coastal areas are occupied by mangrove forests which are dominated by red mangrove (Rhizophora mangle). Numerous mangrove tree islands are seen in northeastern (NE) and central sections but not in southwestern (SW) Florida Bay. Due to their location along the land-sea interface, mangroves are highly vulnerable to environmental changes, particularly sea-level rise and salinity variation. The Everglades National Park (ENP) and Florida Bay are currently undergoing the world’s largest wetland restoration project with the aim of returning the ecosystem to pristine conditions prior to anthropogenic modifications. As a key component of the Everglades and Florida Bay ecosystem, mangroves represent an important source of organic matter to coastal sediments. We present preliminary data on the paleoecological reconstruction of mangrove influences in Florida Bay through a molecular marker (i.e. biomarker) approach. Four piston sediment cores covering between a few hundred to a few thousand years were collected from NE, central and SW Florida Bay, along with several surface sediment and vegetation samples. Based on modern biomass analysis, a specific biomarker for mangroves, namely taraxerol, was applied in this study. Mangroves contain exceptionally high abundances of taraxerol which was detected up to 1.4mg/g, while the other main biomass in the system, including seagrass and sawgrass, do not contain this compound. Taraxerol concentrations combined with other molecular data from n-alkanes and 13C stable isotopes were employed to reconstruct historical mangrove-derived OM inputs to Florida Bay. Our preliminary results show a distinct difference in historical mangrove distributions along a NE to SW transect in the bay. In central and SW areas of the bay, high abundances of taraxerol were observed mainly in the bottom portion of the cores, suggesting a change from a mangrove dominated ecosystem to a seagrass-dominated system as indicated by a reduction in taraxerol abundance up-core and an increase in the relative abundance of the mid-chain n-alkanes (indicative of seagrass-derived OM). The longest core from Central Florida Bay presents an ecosystem transition from freshwater marsh through mangroves to a seagrass dominated system during the last ~4000 years. In contrast, the NE site has a much higher overall abundance of taraxerol in more recent times. These changes are most likely controlled by sea-level rise in Florida Bay through the Holocene. Early marine transgression resulted in a transition from freshwater marshes to mangrove forests, which after continued sea-level rise caused mangrove forests to decline and move further inland, while deeper areas were replaced by seagrasses. Contact Information: Yunping Xu, Environmental Geochemistry Laboratory, Southeast Environmental Research Center (SERC) and Department of Chemistry & Biochemistry, Florida International University, University Park Campus, OE-148, Miami, FL, 33199, Phone: 305-348-2456, Fax: 305-348-4096, Email: Y. Xu [email protected]; R. Jaffé [email protected].


116

Direct Measurement of Denitrification Activity in a Gulf Coast Freshwater Marsh Receiving Diverted Mississippi River Water Kewei Yu1, Ronald D. DeLaune1 and Pascal Boeckx2

1Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA 70803, USA 2Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry (ISOFYS), Ghent University,

Gent, Belgium Wetland loss along the Louisiana coast and excessive nitrate loading into the Gulf of Mexico are interrelated environmental problems. The Mississippi River levee built for flood control has been impeding the supply of fresh water, nutrients and sediment to the coastal wetlands. Without the buffering effect of wetlands on water nitrate level, large amount of nitrate are reaching offshore area, resulting in seasonal hypoxia. The Davis Pond freshwater diversion structure (close to New Orleans, Louisiana, USA) is designed to provide a controlled flow of fresh water and nutrients from the Mississippi River into a target marsh in the Barataria Bay estuary. Nitrate removal by the soil denitrification activity was studied in a freshwater marsh receiving diverted Mississippi River water. Labeled 15N-nitrate was applied at 3.85 g N m-2 into four replicate study plots. Nitrous oxide (N2O) and nitrogen gas (N2) emissions were measured directly using gas chromatography (GC) and isotope ratio mass spectrometry (IRMS), respectively. Results showed that it took 2 weeks to remove the added nitrate with detectable N2O emission for about 5 days. The apparent denitrification dynamics was assumed to follow the Michaelis-Menten equation of Denitrification rate = Maximum denitrification rate × [Nitrate] / (Km + [Nitrate]). The maximum denitrification rate and Km value were determined as 12.57 mg N m-2 h-1, and 6.46 mg N L-1, respectively. Thus the maximum capacity of nitrate removal by the marsh is about 110 g N m-2 yr-1, and about 30% of which is emitted as N2O (an important greenhouse gas). As a typical nitrate concentration in the Mississippi River water 1 mg N L-1, nitrate removal rate by the marsh would be 14.72 g N m-2 yr-1 with no obvious N2O emission. The results of a system dynamic model (using STELLA 8, High Performance Systems, Inc.) indicate that the efficiency of nitrate removal by the marsh depends on the nitrate concentration in the diversion water and its discharge rate. High discharge rate will result in less retention time for the water in the marsh where the water nitrate will be denitrified. The simulation model is a powerful tool in a realistic management in order to reach the best performance of the system. Contact Information: Kewei Yu, Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA 70803, USA, Phone: +1-225-5788832, Fax: +1-225-578-6423, Email: [email protected]


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Reestablishing the Vegetation and Environmental Changes in Beijing Area from 16000-7000 Years B.P. Jiahua Zhang and Fengmei Yao

Chinese Academy of Meteorological Sciences, Beijing, China The 197 samples were obtained from a 820 cm profile in Beijing region, as inferred from sporo-pollen with high resolution, loss-on-ignition, charcoal analysis, surface soil pollen and the earth magnetic field characteristics. The environmental changes from 16000-7000 Years B.P. were reestablished in Beijing Region China; meantime the abrupt climate change was considered. the evolution of vegetation and environmental changes were divided into the ascending order. About 15800-14700 aB.P., the arbors and aquatic plants were sparse, the herbs were dominated by Artemisia and Chenopodiaceae. The climate was cold and dry. About 14700-13400 aB.P., forest developing was limited, it was dominated by conifer in mixed conifer and deciduous brodleved forest, presumably in responded to climate cooling. Aquatic plants began abundant, reflected the widespread development of peats in the low land and the plain in Beijing, the lakes and swamps were developed better. The climate was wet with annual precipitation high than that at present. At 14060 aB.P., the climate with cold and dry corresponded to Gothenburg Drift, and at 13520aB.P.,the accumulation of peat was interrupted as the climate became dry and cold. During 13400 to 12600 aB.P., reflected widespread development of mixed conifer and broad-leaved deciduous forest ,aquatic plants decreased and the swamps reduced, which corresponded to climate gradually became warming and drying. About 12600-11400 aB.P., the trees decreased ,there were alternation of mixed the conifer and broad-leaved deciduous forest once and again, so were aquatic plants ,reflected fluaction of cold and warm in the climate, moisture changed in environment also. From 11400 to 9600 aB.P., the decreasing of trees and increasing of herbs and shrubs suggested an opening up of the vegetation in responded to cooling. About 9600-7000 aB.P., the broad-leaved deciduous forest gradually increased, so were the aquatic plants. The climate changed from cold and dry to warm and humid.

Contact Information: Jiahua Zhang, Chinese Academy of Meteorological Sciences, No.46, Zhonguancun South Street, Beijing, 100081, China, Phone: +8610-68409710, Fax:+8610-62375732, Email:[email protected]


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Preliminary Evaluation of a Laboratory Scale Wastewater Treatment by Constructed Subsurface Flow Wetlands Planted with Ornamental Plants of Commercial Interest F. Zurita1, J. de Anda2, Y. Herrera1 and V. Delgado1

1Centro Universitario de la Ciénega. UdeG. México 2Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, México

The world is experiencing significant growth in human population, and fresh water is becoming a scarce resource. Lakes represent a major source of such freshwater, but are coming under increasing pressure through exploitation for agriculture, industry, drinking water and hydroelectricity generation. This is particularly the case in tropical developing countries. Lake Chapala is the most important natural lake in Mexico and the main fresh water supply for Guadalajara City. The primary tributary to Lake Chapala is the Lerma River. Large quantities of domestic, agricultural, and industrial sewage from the entire Lerma-Chapala basin still flow untreated into the watershed and eventually into the lake, resulting in excessive inputs of phosphorus (P) and nitrogen (N), both known to cause eutrophication. Human water demand from Lake Chapala surpasses the surface supply and groundwater recharge rate. This has resulted in a hydrologic imbalance in its basin. In addition, high nutrient concentrations in the lake have led to degraded water quality, resulting in growth of floating aquatic vegetation and blue green algae. Many authors suggest that the most effective long-term measure for the control of eutrophication in a water body is a reduction in the input of external nutrients. One way to reduce the nutrients coming from point sources, is to remove them by biological treatment, unfortunately the cost of installation and operation of a municipal wastewater treatment plant do not permit the municipal governments to invest in such technologies because of other basic needs that are a priority. An alternative is to develop a cost effective treatment technology, namely a managed artificial wetland, which permits a significant reduction of nutrient contamination along the river and around the lakeshore. The proposed treatment system is less expensive than the existing commercial systems, and is easier to build and operate. Furthermore, this wastewater treatment system allows for the development of a profitable business by producing commercial ornamental flowers that meet all biological safety requirements in order to be delivered to market. Because of the subtropical climatic conditions of the area, it is possible to maintain flower production all year long. Preliminary laboratory scale studies by using five different ornamental plants (Canna hibrids or flaccida, Zantedeschia aethiopica, Strelitzia regina, Anthurium scherzerianum, and Hemmerocallis dumortieri) where proof during four months from September to December 2004. It was evaluated chemical and biological water quality parameters at the inlet and outlet of the feed untreated wastewater. DBO and DQO where reduced in more than 75% in both cases. Phosphorus and nitrogen were removed in more than 50%, and the dissolved oxygen increased from 0.3 mg/liter to 5.8 mg/liter. According with these results it is possible to design a pilot unit to validate the preliminary results giving the opportunity to develop a profitable technology to mitigate the adverse environmental effects of untreated sewages discharged nowadays in several Mexican water bodies.

Contact Information: F. Zurita, Centro Universitario de la Ciénega, UdeG. Departamento de Ciencias Básicas. Av. Universidad # 1115, Ocotlán, Jal. México, Phone: (01)392 92 50026, Email: [email protected]


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Author Index Bold numbers indicate presenting authors.

Allison, J. Bryan......................................................26 Almond, R. A. .........................................................83 Anda, J. de ............................................................. 118 Anderson, Iris C. .....................................................74 Arheimer, B. .......................................................... 109 Arthur, Michael ..................................................... 104 Bailey, E. ............................................................... 4, 6 Baily, Earl..................................................................5 Baker, J......................................................................3 Behrends, L. L. ........................................................83 Behrends, Leslie L....................................... 4, 5, 6, 83 Belmont, M..............................................................22 Belmont, Marco A. ....................................................7 Bloßfeld, S...............................................................14 Boeckx, Pascal............................................... 108, 116 Bohlen, Patrick J........................................................8 Bond, Daniel C. .........................................................9 Borgatti, Rachel.......................................................10 Bouchard, Virginie ..................................................11 Brantley, Christopher G...........................................12 Brown, Don ...............................................................5 Bruland, Gregory L. .................................... 13, 45, 90 Busch, J. ..................................................................14 Cable, Jaye E. ..........................................................49 Callahan, Timothy J........................................... 63, 97 Calva-Benítez, L. G......................................... 15, 106 Canty, Lisa...............................................................51 Castañeda, Edward ...................................... 16, 28, 93 Chambers, Randy ....................................................17 Chi, Chuande...........................................................81 Childers, Daniel L. .............................. 18, 41, 94, 107 Chrastny, V............................................................ 111 Clark, Mark W............................................... 8, 20, 37 Cloutier, Joshua B. ..................................................19 Cohen, Matthew ......................................................20 Conry, T. .................................................................32 Coronado-Molina, C................................................16 Corrales, H...............................................................93 Corstanje, R. ............................................................45 Craft, C. ...................................................................21 Curtis, S. ..................................................................22 D'Angelo, E. M........................................................23 Daoust, R. J. ............................................................24 Das, D. K. ........................................................ 25, 100 Davidson, Gregg R. .................................................39 Davis, J. H. ..............................................................44

Davis, Stephen E., III ........................................26, 28 Day, J. W. ................................................................93 Day, Jason N............................................................58 Day, John W., Jr. ................................... 12, 27, 49, 58 DeBusk, Thomas A. ........................ 29, 31, 51, 55, 80 Defraeye, S. .............................................................30 DeLaune, Ronald D. .......................... 70, 88, 103, 116 Delgado, V............................................................. 118 Dennison, William C. ..............................................10 Dierberg, Forrest E. ......................... 29, 31, 42, 51, 55 Doyle, Robert D. ...............................................32, 96 Doyle, T. W. .................................................. 101, 102 Drouillon, M............................................................33 Du Laing, G................................................. 34, 35, 36 Dunne, E. J. .............................................................37 Ellison, W..................................................................4 Feller, Ilka C............................................................10 Fernández, F. J....................................................... 106 Francisco, A.M. ......................................................68 Freeman, Chris ........................................................38 Frey, Serita ..............................................................11 Fry, B..................................................................... 101 Galicki, Stan ............................................................39 Gambrell, Robert P..................................................40 Gao, Min..................................................................41 Gathumbi, Stanley .....................................................8 Gauthier, D. .............................................................93 Gilbert, Janice..........................................................11 Goodwin, S..............................................................62 Grace, Kevin A........................................................42 Greenway, Margaret ................................................43 Griffith, S. M. ..........................................................44 Grunwald, Sabine .......................................... 8, 13, 45 Gudkov, D. ..............................................................46 Gutiérrez, M. F. .......................................................47 Haberer, J.................................................................95 Hartman, Wyatt H. ..................................................90 Harvey, Judson .................................................. 77, 78 Hefting, M. M........................................................ 109 Herrera, Y.............................................................. 118 Hogetsu, Taizo.........................................................50 Hopkinson, C. S.......................................................24 Horwath, W. R.........................................................44 Hossian, A. T. M. S. ................................................87 Hou, A. .................................................................. 103 Houck, L....................................................................6


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Houdková, Kateřina.................................................89 Houke, L. ...............................................................4, 5 Hunt, P. G. ...............................................................48 Hyfield, Emily C. G...........................................58, 49 Islam, Md. Sajedul...................................................50 Jackson, Scott D.................................................51, 55 Jaffé, Rudolf ........................................19, 41, 65, 115 Jansen, Pat .........................................................4, 5, 6 Jawitz, J. W. ............................................................52 Johnson, Liza M.......................................................63 Joye, Samantha B.........................................53, 59, 67 Jugsujinda, Aroon ....................................................70 Justic, Dubravko ......................................................49 Juston, John .............................................................29 Kameyama, Norikazu ..............................................50 Karathanasis, A. D...................................................23 Katushynskiy, Artur.................................................54 Kharbanda, Michelle................................................55 Koepfler, Eric ..........................................................99 Kolowith, Lauren C. ................................................63 Kravchenko, I. ...................................................56, 57 Kulachinsky, A. .......................................................46 Lane, Robert R.........................................................58 LeBlanc, Cale ..........................................................40 Lee, Rosalynn Y. .....................................................59 Lesage, Els.........................................................60, 61 Li, Lianqing .............................................................81 Li, S. ........................................................................62 Lian, Chunlan ..........................................................50 Long, S.....................................................................95 Lopez, Christel J. .....................................................63 Lösch, R...................................................................14 Luchka, Vitaliy ........................................................64 Maie, Nagamitsu......................................................65 Malecki, Lynette M. ................................................66 Mashina, V...............................................................46 Matheny, T. A..........................................................48 McCormick, P. V.....................................................76 McKee, Karen L. .....................................................67 McKee, Kathleen .......................................................8 McMillan, Sara W. ..................................................82 Medina, E.................................................................68 Megonigal, J. Patrick .........................................21, 69 Meile, Christof.........................................................59 Mendelssohn, I. A....................................................14 Merckx, R. ...............................................................33 Metcalfe, Chris D.......................................................7 Miah, M. A. M.........................................................87 Miao, Shenyu...........................................................70 Morris, James T. ................................................24, 71

Murray, Norman ......................................................40 Mutsert, Kim de .................................................16, 28 Myrold, D. D. ..........................................................44 Naher, Umme A.................................................72, 87 Nair, K. Shadananan ...............................................73 Nazarov, A...............................................................46 Neikirk, Betty B.......................................................74 Neubauer, Scott C. ...................................................74 Newman, Jana Majer .......................................75, 112 Newman, Sue...............................................13, 45, 76 Nietch, C. T. ............................................................24 Noe, Gregory .....................................................77, 78 O’Neil, Judith M......................................................10 O'Connell, M. ........................................................103 Omollo, Judith Akinyi ...........................................110 Omote, J...................................................................79 Osborne, Todd Z................................................13, 45 Owens, Patrick.........................................................80 Pan, Genxing ...........................................................81 Paris, Jeremy............................................................20 Parish, Kathleen.......................................................65 Pauw, N. De.......................................................60, 61 Pederson, Kristin......................................................17 Pezeshki, S. R. .........................................................62 Piehler, Michael F....................................................82 Pier, P. A..............................................................6, 83 Poach, M. E. ............................................................48 Poe, Amy C..............................................................82 Poret, N....................................................................84 Prasad, M. Bala Krishna ..........................................85 Prokofev, Igor ..........................................................86 Putnam, Lorna .........................................................40 Qiu, Aolei ..............................................................113 Quilice, A.................................................................68 Rahman, F................................................................87 Ramanathan, AL. .....................................................85 Ramírez-Vives, F. .................................................106 Reddy, G. B. ............................................................48 Reddy, K. Ramesh ............. 13, 20, 37, 45, 76, 88, 112 Reed, Sharon............................................................11 Rejmánková, Eliška ...........................................89, 98 Richardson, Curtis J.....................................90, 91, 99 Rick, J. J...................................................................92 Rick, S. ....................................................................92 Rivera, G. N. ...........................................................47 Rivera-Monroy, Victor. H. .....16, 19, 28, 84, 93, 106 Rivero, R. G.............................................................45 Romigh, Melissa ......................................................28 Rousseau, D. P. L. .............................................60, 61 Saiers, James............................................................78


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Saleque, M. A..........................................................87 Saunders, Colin ................................................. 41, 94 Savitsky, A. .............................................................46 Scinto, L. J...............................................................95 Scott, Durelle...........................................................77 Scott, J. Thad ..................................................... 32, 96 Sees, M. D. ..............................................................52 Sekula, Emily N. ............................................... 63, 97 Shea, C. .....................................................................4 Shields, F. D., Jr. .....................................................62 Shockley, Mary .......................................................17 Sirin, A. ...................................................................56 Sirová, Dagmara................................................ 89, 98 Smith, S. ....................................................................4 Sparks, E. J. .............................................................23 Steiner, J. J...............................................................44 Story, A. ..................................................................61 Sundareshwar, P. V. .......................................... 90, 99 Sur, Pintu......................................................... 25, 100 Svehla, J. ............................................................... 111 Swarzenski, C. M. ......................................... 101, 102 Tack, F. M. G. ................................. 34, 35, 36, 60, 61 Tan, M. ..................................................................103 Thomas, Burt .........................................................104 Thomas, Cassondra R............................................105 Thompson, Suzanne P. ............................................82 Threlkeld, Stephen R. ..............................................39 Torres-Alvarado, R. ........................................ 15, 106 Trémolières, M. .......................................................30 Trettin, Carl C..........................................................97 Troxler-Gann, T. ...................................................107

Turner, B. L. ............................................................76 Twilley, Robert R. ................... 3, 9, 16, 28, 84, 92, 93 Van Cleemput, O. .................................................108 Van Ryckegem, G. .................................................35 Vandecasteele, B. ....................................................36 Vanrolleghem, P. A. ................................................61 Vanthuyne, D..................................................... 34, 36 Varona-Cordero, F. .................................................47 Verhoeven, J. T. A.................................................109 Verloo, M. G. .................................. 34, 35, 36, 60, 61 Vorster, John .........................................................110 Vrba, J. ....................................................................98 Vymazal, J. ............................................................111 Wang, H. .................................................................52 White, John R. ........................... 7, 22, 42, 52, 66, 112 Wu, Bingyun ...........................................................50 Wu, Xinmin .............................................................81 Wustenberghs, J.......................................................36 Xiangde, Wu..........................................................113 Xu, Xinwang ...........................................................81 Xu, Y. Jun..............................................................114 Xu, Yunping ..........................................................115 Yao, Fengmei ........................................................ 117 Yin, Chengqing ..................................................... 109 Yost, T. .................................................................. 4, 6 Yu, Kewei........................................................ 57, 116 Zhang, Jiahua.........................................................117 Zhirina, Ludmila......................................................86 Zub, L. .....................................................................46 Zurita, F. ................................................................118


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Notes

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