Spatial distribution of soil organic carbon in a typical catchment in Namco Basin

ObjectiveThis study aimed to explore soil organic carbon(SOC)spatial distribution regulations in high mountain alpine meadow basins of Qinghai-Tibet Plateau for a better estimating of SOC content and its variation trends un-der the background of global change and grassland restore.MethodSurface layer(0-10 cm)and bottom layer(20-30 cm) soil samples at different elevations and slope directions were collected to determine SOC contents at different elevations, slope directions and soil layers in a typical catchment in Namco Basin which located in middle part of the Qinghai-Tibet Plateau.Spatial distribution characteristics of SOC in the catchment were analyzed thereafter.ResultSOC of the study area were between 0.95-47.28 g/kg,with the mean value of 13.44 g/kg.SOC showed a decreasing tendency as elevation rose.Compared among different slope directions,SOC displayed higher values on northern slopes(16.41 g/kg)and lower values on southern slopes(8.47 g/kg).SOC have similar values between eastern(12.10 g/kg)and western(12.17 g/kg) slopes.Besides,SOC presented higher values in 0-10 cm shallow layers(20.01 g/kg)than 20-30 cm bottom layers(6.88 g/kg).ConclusionSOC are significantly correlated to elevation,slope direction and soil layer in the study basin.Mean SOC content of the Namco Basin is lower than most of areas of the Qinghai-Tibet Plateau.