Effect Of Plant Vegetation Traits On The Soil Erosion Of Mu Us Sandyland

According to the natural condition of the Maowusu Sandyland, the sandy land is divided into 4 types of area: meadow grassland, grass and irrigated conjointly land, interdune lowland and Achnatherum splendens land types. Through quadrat method study of plant species and plant communities of each type area, according to the field survey, there are mainly 34 kinds of plants, belonging to 16 families, 28 genera, including 10 species of Asteraceae, 5 species of Artemisia and 6 species of Poaceae.The study shows that different dominant species diverse from different typical of targeted areas. Carex tristachya is dominant species on interdune lowland; Glaux maritima L. and Halerpestes ruthenica are sub-dominant species; Achnatherum splendens is dominant species of precarious marsh grass, Artemisia frigida and Psasmmochloa mongolica are subdominant species; Salsola collina Pall. is dominant species in the meadow; Setaira viridis beauv, A′frigida. and Artemi siascoparia Waldst. EtKit are also sub-dominant species; Artemisia ordosica and Caragana korshinskii kom. are dominant species on grass and shrub sand dune grassland.Based on the vegetation coverage levels, soil erosion traits were investigated under different vegetations in Mu Us Sandyland. Four different vegetation forms of Salix cheilophila, Caragana microphlla, Artemisia sphaerocephala, and Achnatherum splendens were selected as test samples for soil erosion measurements. Soil loss or accumulation under the measuring pole was used as a judgment for soil erosion degrees. The results showed that soil erosion occurred under vegetation coverage of 30%, while no obvious soil erosion occurred under vegetation coverage above 60%. Threshold coverages for the four forms are all 60%. Form Caragana microphylla and Form Artemisia Sphaerocephala were considered as proper vegetations for soil wind erosion control in Mu Us sandyland region.Meanwhile, based on the areo-dynamic experiments results in the wind tunnel experimental lot, it could be concluded as follow: threshold erosion wind velocity increases coping with the vegetation coverage, but the threshold vegetation coverage shared the non-linier connections with wind velocity, which increases to reach a certain value--Threshold value(erosion will not happen however strong the wind is). This threshold value functions to control the erosion. Based on the areo-dynamics, vegetation increased the air roughness, frictional resitance and threshold wind velocity, in order to conter-act the wind erosion speed.