CO2 AND CH4 DYNAMICS OF A SPHAGNUM-DOMINATED PEATLAND IN WEST-VIRGINIA

Climatic change could bring about net release of carbon dioxide (CO2) and/or methane (CH4) from the deep peat deposits in northern peatlands into the atmosphere. To provide insight into this hypothesis, we stud ied net flux of CO2 and CH4 in Big Run Bog, West Virginia, which has a temperate climate, making it an analog to evaluate climatic change im posed on more northern counterparts. Net CO2 flux ranged from -564 to 300 mg C m-2 hr-1. Measurements made during the nighttime showed that net CO2 flux increased exponentially with increasing air temperature, whereas CO2 sequestration increased with increasing air temperature fo r daytime measurements. Net CH4 flux ranged from -2.3 to 70 mg C m-2 h r-1, showing no consistent relationship to temperature or water table level. Net efflux for both CO2 and CH4 was tenfold higher from peat co res incubated in a greenhouse compared to field measurements. Even cor es drained and allowed to dry for 8 days showed moderately high flux f or both CO2 and CH4. The enhanced efflux seemed to be due to altered h ydrology rather than increased rates of bacterial production (measured in anoxic, in vitro incubations) which could account for only 50% of the whole-core flux. Presumably the remainder was CO2 and CH4 stored i n the peat cores at the time of collection. Overall, the results sugge st that a temperate climate imposed on northern peatlands could mobili ze stored carbon and increase CO2 and CH4 efflux into the troposphere. Studies involving peat cores must insure that CO2 and CH4 dynamics me asured in vitro mimic those in situ.