Ecosystem-atmosphere exchange of CO 2 in a temperate herbaceous peatland in the Sanjiang Plain of northeast China
Northern peatlands contain a considerable share of the terrestrial carbon pool, which will be affected by future climatic variability. Using the static chamber technique, we investigated ecosystem respiration and soil respiration over two growing seasons (2012 and 2013) in a Carex lasiocarpa -dominated peatland in the Sanjiang Plain in China. We synchronously monitored the environmental factors controlling CO 2 fluxes. Ecosystem respiration during these two growing seasons ranged from 33.3 to 506.7 mg CO 2 –C m −2 h −1 . Through step-wise regression, variations in soil temperature at 10 cm depth alone explained 73.7% of the observed variance in log 10 (ER). The mean Q 10 values ranged from 2.1 to 2.9 depending on the choice of depth where soil temperature was measured. The Q 10 value at the 10 cm depth (2.9) appears to be a good representation for herbaceous peatland in the Sanjiang Plain when applying field-estimation based Q 10 values to current terrestrial ecosystem models due to the most optimized regression coefficient (63.2%). Soil respiration amounted to 57% of ecosystem respiration and played a major role in peatland carbon balance in our study. Emphasis on ecosystem respiration from temperate peatlands in the Sanjiang Plain will improve our basic understanding of carbon exchange between peatland ecosystem and the atmosphere.