| Taking Sharli, Taoli&Chengchuan in Mu Us sandy land as examples, this dissertation studied species composition, function type composition and biodiversity characteristics of vegetation in settle-grazing pasture. Numerical classification was used.. Vegetation and soil characteristics and degradation gradients was studied. The main research findings are as follows:(1)There are 33 families 89 genuses 107 species at the settle-grazing pasture in Mu Us sandy land.The dominant families are Asteraceae,Gramineae,Leguminosae and Chenopodiaceae From the perspective of life-form function type of community, the number of perennial herb is the most, the number of annual herb is on the second place and the number of shrub and semi-shrub is the least. From the perspective of hydro-ecological function type of community, the number of mesophyte is more than xerophyte. From the perspective of palatable function type of community, the number of preference of livestock forage is the least. The number of not-eating livestock forage is on the second place. The number of edible of livestock forage is the most.(2)The TWINSPAN classification results in three sites indicate that the quadrats are divided into two types. The one is miscellaneous grass type which is based on perennial and annual herb and mainly distributes between sand dunes. The other one is shrub type which is based on Artemisia ordosica Krasch. and mainly distributes on sand dunes.(3)The vegetation community distribution is as follow rules. In the region close to house, the species and function type richness and the coverage of community and function-type drop. Soil nutrients and fine materials reduce. The biological soil crust is worse. It was the opposite situation away from house.Under certain grazing pressure, in the region close to house, the coverage of mesophyte and perennial herb and the number of species and coverage of not-eating livestock forage increase to some extent.
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