EFFECT OF THE WATER REGIME ON THE SOIL CARBON FRACTIONS AT SWAN LAKE ALPINE WELAND IN TIANSHAN MOUNTAIN, CHINA

摘要

This paper analyzes the total C (TC), soil organic C (SOC), dissolved organic C (DOC), microbial biomass C (MBC), and labile organic C (LOC I and LOC II) at 0 to 100 cm depths at permanent water (PW), seasonal water (SW) and no water areas (NW) in the Swan Lake alpine wetlands to study the effects of water regime on the soil carbon and labile carbon fractions. Results indicated that soil carbon and labile carbon fractions are mainly stored in the 0 to 30 cm depth at three water conditions, and the soil carbon and labile carbon fractions sequestered in PW and SW exceeded those stored in NW. Following wetland degradation from PW to NW, water improved the sequestration of soil carbon in Swan Lake alpine wetlands. SOC content are 81.48, 98.74 and 27.48 g kg~(-1) at the O to 100 cm depth at PW, SW and NW, respectively. The DOC content is 10.32, 11.73 and 0.71 g kg~(-1), respectively. The LOC II content is the lowest, specifically, 227.4, 75.3 and 69.1 mg kg~(-1) at the PW, SW and NW, respectively. In conclusion, the changeable of the period of water logging from the PW to NW in the wetlands will increase the mineralization of soil carbon and lead to a loss of soil carbon.