Effects of Different Vegetation Types on Soil Erosivity in Dry and Hot Valley of Yajiang River Basin

Four species of typical vegetation of Cupressus gigantean community, Pinus densata community, Sophora moorcroftiana community and Artemisia sacrorum community in the dry heat valley of Yajiang River were selected. The soil of 0−20 cm under the vegetation was collected, and the soil erodibility and its influencing factors were analyzed, and the correlation between soil erodibility and physical properties was analyzed.Results show that soil bulk density under each vegetation type is extremely significant. The soil is mainly composed of silt and sand, and the organic matter content is 20.19−37.99 g/kg. The proportion of particle size less than 0.25 mm is the largest in the mechanical stable aggregates of soil. The particle size of most wet-screened aggregate is larger than 0.25 mm, and the destruction rate is 17.03%−24.95%.The soil erodibility K value distribution ranged from 0.156 3 to 0.223 0 in the study area, the order is sand sorghum> alpine pine> giant cypress> iron stalk. Soil erodibility is significantly positively correlated with clay content and particle content, and is significantly negatively correlated with sand content, negatively correlate with total porosity and capillary porosity, and positively correlate with non-capillary porosity.