| The desertification of grassland is a serious problem of environment and society, which is also the main reason of restriction for grassland resource utilizing and sustainable development of economy in the drought and semi-drought region in north of China. It is purposed to look into the causes, the mechanisms and the ecological processes of grassland desertification and the measures of restoration, for discussing the desertification grassland in Yanchi of Ningxia. A survey for the species composition of vegetation, community structure, species diversity, the ecological process of vegetation restoration and the remote sensing of monitoring grassland vegetation under the direction of theory of restoration ecology, method of field investigation and laboratory analysis. Results are as following:(1)In 2003, the vegetation situation is the best year in recent years of Yanchi county. Because of the smooth implementation of the ban in all over the county, regional vegetation communities gradually towards positive succession, anticipated in the next 5-10 years, the A.ordosica,Cynanchum komarovii and Sophora alopecuroides will be have main position in sandy grassland vegetation of Yanchi. Over the past 5 years, the vegetation dynamics of land and 5 different types of community composition of the study show that exclusive measures grassland desertification is one of the most effective and economic restoration of vegetation. Especially in returning farmland to pasture and natural grassland, fenced way is effective management in this aspect of vegetation restoration and protection application.(2)The life of vegetation in three different closing years most are herbaceous plant, old fencing areas to perennial mainly, but also one-year-old plants account for a large proportion. After 3 different closing years, the vegetation cover, average height and aboveground biomass are not has significant difference. Desertification grassland enclosed 4 years later, proper mowing or grazing use, on the one hand can make such soil skinning loose, the water was limited to make full use of plants, the lawn vegetation resume as soon as possible; on the other hand can inhibit the expansion of the dominant species so that the associated species, access to special kind of living space, thereby increasing plant species diversity and value characteristics, productivity enhancement.(3)Basing on NDVI and the remote sensing of monitoring grassland vegetation, the vegetation state have been improvement in Yanchi county from the year 2001 to 2004. The medium vegetation fraction is the main types of vegetation fraction in Yanchi. Its area is large; its ecological structure is very fragile and it is the stress area of desertification prevention and cure in the future. At the same time, it is important to improve the protection of the vegetation of medium-high coverage and high coverage.
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