雅江流域干热河谷不同植被类型对土壤可蚀性的影响

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

选取雅江干热河谷地带的巨柏群落、高山松群落、砂生槐群落、铁杆蒿4种典型植被,采集植被下0~20cm土壤,对土壤可蚀性及其影响因素进行分析,并对其土壤可蚀性和物理性质进行相关性分析。结果表明:各植被类型下的土壤容重呈极显著差异,土壤主要以粉粒、砂粒为主,有机质含量为20.19~37.99g/kg;土壤机械稳定性团聚体中,以<0.25mm粒径所占比例最大,经湿筛后,团聚体以>0.25mm粒级为主,团聚体破坏率在17.03%~24.95%。研究区土壤可蚀性K值分布范围在0.1563~0.2230,由大到小依次表现为:砂生槐>高山松>巨柏>铁杆蒿。土壤可蚀性与黏粒含量、粉粒含量呈极显著正相关,与砂粒含量呈极显著负相关,与总孔隙度、毛管孔隙度呈显著负相关,与非毛管孔隙度呈显著正相关。

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 from0.156 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.