Characteristics Of Typical Vegetation Communities And Soil Nutrients In Ali Area

Ali Region is located in the northwest of the Qinghai Tibet Plateau.Vegetation research in Ali region can provide theoretical support for exploring and protecting the vegetation environment in Ali Region.In this study,we used the survey method as the community sample method,and used the multivariate statistical analysis methods such as twin-span and species diversity analysis to systematically analyze the species composition of plant community,the types of formation and cluster,the species diversity of sample plot and cluster,the spatial distribution of soil nutrients,and the relationship between species diversity and soil nutrients in Ali area.(1)There are 102 species of seed plants in Ali area,which belong to20 families and 55 genera.The main species are Compositae,Leguminosae,Gramineae and Cyperaceae.The most dominant family is Gramineae.According to the distribution types of genera,all plant species can be divided into 9 distribution types and 5 distribution subtypes.Temperate distribution genera are the main distribution types,with a total of 41 genera,accounting for 74.55 %.The north temperate distribution genera with the most distribution genera are 21 genera,including one distribution subtype.(2)According to the important value of each species in the sample plot,the vegetation in Ali area can be divided into 14 formation types and25 cluster types,among which the widely distributed formation types are Stipa Plumeria formation,Stipa purpurea formation,sand fixing grass formation and Stipa Gobi formation.(3)The species diversity of Nitu county is the lowest among all the counties,and the species diversity of Coqin county is the highest among all the clusters.On the whole,the diversity of vegetation in Ali area gradually decreases from East and south to northwest,showing obvious zonal change.The results show that the plant diversity in Ali area is affected by climate,micro environment(including soil texture,slope aspect,topography,water source and human intervention)and other factors.(4)The results showed that there were great differences in the spatial distribution and location distribution of soil nutrient indexes in the typical vegetation communities of four counties in Western Ali,and the contents of nutrient elements were low as a whole.The ecological environment is sensitive and easy to be destroyed,the soil development time is short,the soil layer is shallow and coarse,the anti erosion ability is very low,and the lack of N element is relatively high,and the degree of salinization is high.There is a significant correlation between soil alkalization and vegetation degradation.The vegetation grows slowly and sparsely,and the vegetation shows obvious degradation trend.Therefore,it should be taken as the key protection area of ecological environment to reduce the impact of agriculture,animal husbandry and other activities.