Simulating Effects of Temperature and Moisture on Carbon Emission of Permafrost Peatland in Mohe, China

The response of stores of carbon in peatland to global warming is a major uncertainty in predicting the future carbon budget. We used a short-term laboratory incubation to simulate effects on the potential CO₂ emission of peatland soil in Mohe, China under soil temperature (5, 10 15 and 20degC) and soil moisture (0, 30, 60, 100%WHC and completely water saturated). The rates of peat carbon mineralized decreased greatly in the earlier phase, but became stabile after 20 days and total carbon mineralization ranged 20.04 to 112.92 mg across sites and experiment treatments. Carbon mineralization rates decreased with soil depth, increased with temperature and reached highest rates at 60%WHC at the same temperature for all treatments. The calculated Q₁₀ values ranged from 1.878 to 2.181, varying with the soil depths and soil moisture. The sensitivity of C_flux to moisture depend on temperature. However the Q₁₀ was not significantly affected by soil moisture and depth. We developed a two compartment model to predict the measured CO₂ emission as a multiplicative function of temperature and moisture and the model predicted C_flux very well (R²>0.888, P<0.001). Our results indicate that the Mohe peatlands would lead to a positive feedback effect on climate change. It is necessary to include such responses in models science they might represent a potential C emission source to peatland ecosystem.