The Effects Of Different Management Modeson Erosional Features Of Deteriorated Grasslands In Xilin River Basin

This paper does researches by aiming at vegetation community characteristics, soil characteristics, wind erosion characteristics andwater erosion characteristics under six management modes, the natural grasslands never gnawed by domestic animals, the pasturable grasslands which have frequent human activities and are seriously gnawed by domestic animals, the Agropyron mongolicum Keng with enclosure management+Astragalus melilotoides Pall.allocation grasslands, the Agropyron mongolicum Keng+Medicago sativa L. allocation grasslands, the Bromus inermis Leyss.+Astragalus melilotoides Pall.allocation grasslands and the Bromus inermis Leyss.+Medicago sativa L. allocation grasslands on deteriorated grasslands of Xilin River basin, conclusions are as the following:(1)The vegetationheight, vegetation, species number, species richness in the grasslands with the enclosure andgrass seed after-culture management are superior to those in natural grasslands and pasturable grasslands, meanwhile, the clay particle and silt particle contentof surface layer increases, the sand grain contentdecreases, themoisture content of surface of soil and organic content are also higher than those in the unmanaged grassland.(2) Comparing to natural grasslands:thesurface roughness of pasturable grasslands is low, and the sediment runoff is high, and the soil drifting is serious; while the surface roughness of managed grasslands increases, and the sediment runoff decreases, which can effectively control the soil drifting.(3) The effects of producing runoff time delaying, runoff producing and sediment production decrease in artificial management grassland (except vegetationallocation of Bromus inermis Leyss.+Astragalus melilotoides Pall.) is obvious, the vegetationallocation of Mongolian wheatgrass+sweet clover obviously weakens the degeneration degree of water erosion to soil.(4) Use principal component analysis to comprehensively judge the order of the six management modes:Agropyron mongolicum Keng+Astragalus melilotoides Pall, allocation grassland>Bromus inermis Leyss.+Medicago sativa L. allocation grassland>Agropyron mongolicum Keng+Medicago sativa L. allocation grassland > Bromus inermis Leyss.+Astragalus melilotoides Pall.allocation grassland> natural grassland>pasturable grassland.In conclusion:under enclosure condition, the vegetation allocation model of Agropyron mongolicum Keng+Astragalus melilotoides Pall.clover can effectively reduce the erosion effect of wind and water erosion to soil, and is more appropriate to the restoration and improvement of deteriorated grassland vegetation and soil in Xilin River basin.