PARENT SESSION
Poster Session # 13: Biogeochemistry, Photosynthesis, and Respiration.
Tuesday, August 5 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.
Contrasting controls on denitrification in a natural and an artificial wetland in the Appalachian mountains.
Kulkarni, Madhura*,1, 1 University of Maryland Center for Environmental Science, Frostburg, MD, USA
ABSTRACT- The denitrification dynamics of soils from a wetland in a high-elevation reclaimed mineland and a natural, high-elevation wet meadow were studied through late spring and summer. Soils from the contrasting wetlands had very different denitrification rates as determined in anaerobic slurry incubations with varying levels of added nitrate and dextrose. The reference site (natural wetland) soils denitrified at significantly higher 'baseline' (no amendments) and 'potential' (high dextrose and nitrate amendments) rates than the mine soils. The baseline denitrification rates scaled areally to 38600 
g N2O-N m-2 hr-1 (SD = 9800) and 33000 g N2O-N m-2 hr-1 (SD = 5000) in the natural and artificial wetlands, respectively. The potential denitrification rates were 67700 g N2O-N m-2 hr-1 (SD = 19000) and 27200 g N2O-N m-2 hr-1 (SD = 7700), respectively. Furthermore, denitrification patterns were shown to be controlled by differing factors at each site, though anoxia-related factors played a large role at both sites. Temperature was the only other factor established to have a relationship with denitrification dynamics at the mine site while temperature, nitrate, and dextrose were all shown to have relationships with those of the natural wetland. Baseline and potential denitrification rates changed over the spring and summer sampling season at both sites. These results suggest that artificially created wetlands in Appalachian reclaimed minelands may exhibit lower denitrification rates and less sensitivity to biogeochemical controls than natural wetlands in the same environment.
Key words: wetlands, nitrogen cycling, denitrification, mining