SS3.12 Large Scale Ecosystem Manipulations
Date: Thursday, June 13, 2002
Time: 5:00:00 PM
Location: Carson C
 
VenkiteswaranJJ, University of Waterloo, Department of Earth Sciences, Waterloo, Canada, jjvenkit@uwaterloo.ca
Schiff, S, L, University of Waterloo, Department of Earth Sciences, Waterloo, CANADA, 
Boudreau, N, M, University of Waterloo, Department of Earth Sciences, Waterloo, CANADA, 
Matthews, C, J, Department of Biological Sciences, Edmonton, Canada, 
Joyce, E, M, Department of Biological Sciences, Edmonton, CANADA, 
St. Louis, V, L, Department of Biological Sciences, Edmonton, CANADA, 
Beaty, K, G, Fisheries and Oceans Canada, Experimental Lakes Area, Winnipeg, Canada, 
Bodaly, R, A, Fisheries and Oceans Canada, Experimental Lakes Area, Winnipeg, CANADA, 
Saquet, M, A, University of Waterloo, Department of Earth Sciences, Waterloo, CANADA, 
Maurice, K, T, University of Waterloo, Department of Earth Sciences, Waterloo, Canada, 
 
GREENHOUSE GAS FLUXES FROM FLOODED BOREAL FOREST RESERVOIRS (FLUDEX): CARBON CYCLING PROCESS INFORMATION FROM 13C/12C IN DIC, CH4, AND 18O/16O IN O2.
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Understanding the sources of greenhouse gas (GHG) production during flooding of boreal uplands is one objective of the FLUDEX experiment at ELA. The decomposition of flooded organic matter produces DIC and CH4 and consumes O2. Information on processes (decomposition, photosynthesis and CH4 oxidation) can be gained from stable isotopes. During the first 3 years of the FLUDEX experiment, samples from the inflow, outflow, water column and benthic chambers were collected for analysis of 13C/12C in DIC and CH4 and 18O/16O in O2. Although decomposition from flooded vegetation and soils dominates the GHG flux from the FLUDEX reservoirs, isotopic analyses show that photosynthesis plays an important role in carbon and O2 cycling. Benthic photoautotrophs significantly reduce the DIC flux across the sediment-water interface and produce O2. Approximately half of the potential reservoir CH4 pool is removed by CH4 oxidation, facilitated by the produced O2.