Study On Ecological Restoration Of Degraded Grassland In Duolun County

Duolun County is in the east of Hunshandake Sandy Land, and it is a typical farming-pastoral zone of the North of China.The water and soil loss, wind erosion and desertification in this area are very serious as a result of rapid growth of population and unreasonable land use. We collect the data of vegetation, sand storm, wind erosion, siol moisture, ground water level and social economic form, and research the ecological restoration effect of various artificial measures on degraded grassland by experiment and field monitoring. The major conclusions are as following:(1) There are abundant plant species in Dunlun County, and the seed plants belong to 75 family, 258 genus and 544 species. In all of them, there are 58 family,121 genus and 192 species of edible plants; 69 family,164 genus and 282 species of medicinal plants; 22 family,35 genus and 50 species of ornamental plants; 15 family,31 genus and 38 species of industrial plants. If we can plant and use them reasonably, the ecological environment and biodiversity could be prevented effectively; furthermore, the life level and economic could be promoted.(2) The frequency and last time of sand storm reduce gradually through almost 10 years ecological construct in Duolun County. Meanwhile, the wind-erosion amount of sand dune is reduced as years; moving dune turns to fixed and semi-fixed dune.(3) The spatial heterogeneity of granule diameter means the biger crown diameter of shrub is, the more fine sand is. But the height of shrub has less influence on the percentage composition of sand-particle diameter. The vegetation coverage has obvious influence on siol moisture of 5-10cm. The siol moisture of grassland with artificial measres is much bigger than it of the natural grassland and sandy land without artificial measres. Planting foreast in sandy land has no obvious effcet on siol nutrient.(4) Enclosre is one of the effective measures to recover degraded grassland. In enclosed area, there are more perennial; and the height, coverage and biomass are all biger than them out of enclosed area. Planting artificial vegetation improves the ecological environment of sandy area. As the years of artificial vegetation increasing, the types of vegetation in area are higher. Vegetation community characteristic of differert years has direct influence on siol moisture. As the vegetation community is stable gradually, the desity and coverage increase obviously. So the evaporation capacity is lower and the soil moisture increase.(5) The major driving force of land use change in Duolun County are economic-policy and population factors. Unutilized land and farmland turning to grassland and forest enhances the land use capability. It shows that the ecological restoration measures such as the project of combating wind and sand storms in the areas of Beijing and Tianjin, returning farmland to forest and enclosure and so on, has active effect and controls the desertification of degraded grassland and improves the ecological environment.