CO 2 and CH 4 dynamics of a Sphagnum ‐dominated peatland in West Virginia

Climatic change could bring about net release of carbon dioxide (CO 2 ) and/or methane (CH 4 ) from the deep peat deposits in northern peatlands into the atmosphere. To provide insight into this hypothesis, we studied net flux of CO 2 and CH 4 in Big Run Bog, West Virginia, which has a temperate climate, making it an analog to evaluate climatic change imposed on more northern counterparts. Net CO 2 flux ranged from −564 to 300 mg C m −2 hr −l . Measurements made during the nighttime showed that net CO 2 flux increased exponentially with increasing air temperature, whereas CO 2 sequestration increased with increasing air temperature for daytime measurements. Net CH 4 flux ranged from −2.3 to 70 mg C m −2 hr −l , showing no consistent relationship to temperature or water table level. Net efflux for both CO 2 and CH 4 was tenfold higher from peat cores incubated in a greenhouse compared to field measurements. Even cores drained and allowed to dry for 8 days showed moderately high flux for both CO 2 and CH 4 . The enhanced efflux seemed to be due to altered hydrology 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 CO 2 and CH 4 stored in the peat cores at the time of collection. Overall, the results suggest that a temperate climate imposed on northern peatlands could mobilize stored carbon and increase CO 2 and CH 4 efflux into the troposphere. Studies involving peat cores must insure that CO 2 and CH 4 dynamics measured in vitro mimic those in situ.