Spatial distribution of soil organic carbon under alpine wetland around Qinghai Lake

As a major part of terrestrial carbon pools,soil organic carbon plays an important role in the global carbon cycle.Selected alpine wetland soil in Qinghai Lake for study object,this paper studied characteristics of soil organic carbon(SOC)content and its spatial variability.Results showed that soil organic carbon content in the 0~10 cm soil layer was the highest,with mean of 2.82±1.56%.With the depth of the soil deepening,its content was decreased gradually.the average content of soil organic carbon in the 10~20 cm,20~30 cm and 30~40 cm soil layer was 2.01±1.03%,1.63±0.87% and 1.21±0.91%,respectively;the average content of soil organic carbon in the 0~40 cm layers throughout the study area was only 1.92±1.27%.Semi-variance function and the variogram analysis results showed that the models of soil organic carbon content in the 0~10 cm,10~20 cm and 20~30 cm soil layers obeyed the spherical model.The models of SOC in 30~40 cm layer and the average of 0~40 cm layer obeyed the exponential models.And also the analyses of the soil organic carbon isotropic and anisotropicunder different depths indicated that SOC existed in higher spatial heterogeneity.