Characteristics of soil carbon density distribution of the Kobresia humilis meadow in the Qinghai Lake basin

Soil is the largest carbon stock in the terrestrial ecosystem, storing about two-thirds of organic carbon in the terrestrial biosphere. Our understanding on the dynamic change of soil organic carbon belongs to one of the important issue in terrestrial carbon cycle. Kobrecia humilis meadow is one major grassland type on the Qinghai-Tibetan Plateau, which has the high organic matter in soil. To provide basic data and theoretical reference on accurate assessments of the Qinghai-Tibetan Plateau alpine meadow ecosystem carbon source/sink effect, this paper determined the soil organic density through measuring the soil bulk density and organic carbon content under different degrading Kobresia humilis meadow in the Qinghai Lake basin. Moreover, soil organic densities in Kobresia humilis meadow were evidently higher than the mean of alpine grassland and meadow in the Qinghai-Tibetan Plateau and in the Qinghai Province and across the China, highlighting that we could not neglect it in evaluation soil organic stock across the wholet Qinghai-Tibet plateau.