Effects of elevated CO on fen peat biogeochemistry

Effects of elevated atmospheric CO2 concentration on northern peatland biogeochemistry was studied in a short-term experiment. Eight intact soil cores Ž11-cm diameter 40-cm depth. with Juncus and Festuca spp. were collected from a calcareous fen in north Wales. Half of the cores were incubated under 350 ppm CO2 concentration, whilst the other four cores were maintained at 700 ppm CO2. After a 4-month incubation, significantly higher biomass Žroot shoot algal mat. was determined under elevated CO2 conditions. Higher emissions of N2O and CO2, and higher concentration of pore-water DOC Ždissolved organic carbon. were also observed under elevated CO2. However, no significant differences were found in CH4 emission or soil enzyme activities Ž -glucosidase, phosphatase, and N-acetylglucosaminidase. in the bulk soil. Overall, the results suggest that elevated CO2 would increase the primary productivity of the fen vegetation, and stimulate N2O and CO2 emissions as a consequence of an enhanced DOC supply from the vegetation to the soil microbes.