风水复合侵蚀下锡林河流域不同管理方式草地表土粒度特征

Soil Particle Size Distributions of Different Management Styles Under Complex Wind and Water Erosion in Xilin River Basin

结合锡林河流域风水侵蚀情况,对锡林河流域围封天然草地、放牧草地、封育种植草地表层(0~5 cm)土壤粒度特征及其与风蚀、水蚀关系进行研究,结果表明:封育种植草地较放牧和天然草地在降低土壤风蚀和水蚀方面均起到了较明显的作用;锡林河流域草地表层土壤粒度组成以砂粒为主,其所占比例为75%~82%,放牧草地较天然草地及封育种植草地土壤粒度粗化明显,封育种植草地中蒙古冰草+草木樨草地土壤颗粒分选性较差,其余草地土壤颗粒分选性均为中等;研究区内粒径在160μm左右土壤颗粒为易受侵蚀土壤颗粒;研究区土壤粒度组成特征与风蚀、水蚀均有明显相关性,尤其与近地面20 cm风速和径流产流总量联系最为密切。

Combined with the situation of wind and water erosion in the Xilin River Basin, particle size distributions of topsoils （0-5 cm） and their relations with wind and water erosion were studied in different management styles including enclosed natural grassland, grazing grassland and enclosed planting grassland in the Basin. The results showed that enclosed planting grassland played a more significant role in controlling soil water and wind erosion than grazing and natural grasslands. Sands were dominant in soil particles with a proportion of 75%-82% in the Basin. Compared with the natural and artificial grasslands, soil coarsening is obvious in grazing grassland. Soil particle sorting was poor in Mongolia wheatgrass and clover grasslands of enclosed planting grassland, while were medium in other grasslands. Soil particles （about 160 ~tm in size） are more erodible. Soil particle distribution is significantly correlated with wind and water erosion, especially correlated with wind speed about 20 cm above the ground and the total amount of runoff.