Kathryn Drumm - Biogeochemistry
Kalamazoo College, Michigan
Carbon Monoxide Flux in Four Wetland Communities
The production of CO, CO2, and CH4 by sediment from four wetland communities was measured over a period of 4 days. CO production was documented in intact cores from freshwater wetlands, but not brackish wetland sites. Sediment slurries were incubated anoxically in serum bottles, half of which had CO added to the headspace. Bottles were treated with either sodium molybdate, BES, or a control. Sodium molybdate was used to inhibit sulfate reduction and BES was used to inhibit methanogenesis. Inhibition of microbial processes did not result in significant differences in CO concentrations. Freshwater wetlands were found to produce CO at a greater rate than brackish wetlands, absent the addition of CO. Soils were only observed to consume CO when the gas was added to the headspace. Brackish wetlands were found to consume CO at a greater rate than freshwater wetlands. These results conflict with previous studies, which assumed soils to be net consumers of CO.