Temperature Sensitivity of СO2 Efflux from the Surface of Palsa Peatlands in Northwestern Siberia as Assessed by Transplantation Method

Peatland soils in permafrost area are among the major components of global carbon cycle. In the case of predicted climate change, they may act as a significant source of greenhouse gases efflux. A four-year transplantation experiment (transplantation of soil cores of 20 cm in height and 10 cm in diameter to other natural positions) with the peat horizon was arranged to assess the temperature sensitivity of CO2 efflux from palsa peatlands in the north of Western Siberia. The rise in temperature by 7°С caused a positive feedback (30–70%) of CO2 efflux (measured by the closed chamber method) from transplanted soils as compared with the control. Temperature dependence of CO2 efflux from transplanted soils had the highest value (R2 = 0.8) in the first two years as a result of maximum contrast of temperature conditions between sites and decreased in the next two years. On the contrary, the temperature sensitivity of CO2 efflux from transplanted soils showed a high value during most of observations (Q10 = 3–6) thus indicating the increased rate of organic matter mineralization in peat soils of permafrost area for a long (four years) period. Our results might be useful for calibration of regional carbon cycle data sets that consider the contribution of organic permafrost-affected soils.