Research On The Features Of Soil And Vegetation Variation About Different Type Of Alpine Cultivated Grassland

In this study,Maqin Country Tibetan Autonomous Prefecture of Golog Qinghai Province as the experimental field,the monocropping cultivated grassland in 2009,mixed planting cultivated grassland in 2009, the monocropping cultivated grassland in 2007 mixed planting cultivated grassland in 2006 were the research objects in 2013 and 2014 respectively. The height,coverage,species numbers of vegetation,aboveground biomass, underground biomass and soil water content, nutrient were surveyed respectively.How to change they were that the the character of community structure, biomassseasonal dynamics and physical and chemical properties of soil between the monocropping cultivated grassland and mixed planting cultivated grassland in 2009;Whether the difference was obvious about the character of community structure and physical and chemical properties of soil on the monocropping cultivated grassland in 2009 and 2007,mixed planting cultivated grassland in 2009 and 2006?This will provide basic data for sustainable utilization of alpine cultivated grassland The main results obtained as follows:The above-ground biomass,under-ground biomass,important value and soil nutrient content had not show significant difference,as well as Shannon-Wiene index and Pielou,but the interannual difference on above ground biomass,species richness index and Simpson index showed significant difference(P<0.05). So,the community stability and grazing tolerance are higher of mixed planting cultivated grassland than monocropping cultivated grassland in 2009.The biomass and importance value were higher in 2009 monocropping cultivated grassland than that in 2007, however,the biodiversity,soil water content and soil nutrition content were higher in 2007 monocropping cultivated grassland. These will illustrate that the monocropping cultivated grassland in 2007 has no significant degradation phenomenon,and meanwhile,the physical and chemical characteristics of soil were improved.So the Poa pratensis L.cv.Qinghai monocropping cultivated grassland is beneficial to the development of cultivated grassland.The vegetation characteristic and soil physicochemical properties had not significanted difference totally between mixed planting cultivated grassland in 2009 and mixed planting cultivated grassland in 2006,but the degree of succession of mixed planting cultivated grassland in 2006 is higher,and is closer to the natural vegetation characteristic,so the community stability and grazing tolerance that was judged by the interannual difference from2013 to 2014 of mixed planting cultivated grassland in 2006 is higer.