Study On The Coupling Relationship Between Vegetation And Soil In Different Degradation Stages Of Leymus Chinensis Grassland

Through the study of Leymus chinensis grassland degree of different stages of vegetation and the corresponding variation characteristics of soil nutrient,through clustering analysis will sample area is divided into six different degradation stages,explore different degradation stages of the coupling relationship between vegetation and soil,in order to understand the change trend of different stages of degradation of vegetation and soil and internal relations,which will provide a scientific basis for the recovery of vegetation and soil,also provide theoretical reference for the science of grassland utilization and protection.The research results are as follows:(1)There were no significant changes in community coverage,number of plant species,available P,total N,total P and total K in all indexes of the six plots selected.Community height,aboveground biomass,p H,electrical conductivity,alkali-hydrolyzable nitrogen,available potassium,organic carbon,sucrase,urease and catalase changed significantly.(2)The degree of soil degradation was closely related to the degree of vegetation degradation,and there was a significant correlation between the community height and soil nutrients except potassium.Aboveground biomass was significantly correlated with available phosphorus,p H,total nitrogen,organic carbon and sucrase.Soil urease,sucrase and catalase were significantly correlated with soil height,total nitrogen,alkali-hydrolyzable nitrogen,organic carbon,p H and electrical conductivity.(3)Through cluster analysis,the original six degraded sample plots in the study area were divided into four degradation stages,namely,non-degraded,mild degraded,moderate degraded,and severe degraded.At different degradation stages,the community height,aboveground biomass,alkali-hydrolyzable nitrogen,available potassium,organic carbon,sucrase,urease,catalase,p H and electrical conductivity changed significantly.(4)All the indexes were screened by principal component analysis method and combined with the correlation between the indexes,urease,sucrase,catalase,p H and electrical conductivity were taken as the sensitive indexes in the degradation stage of Leymus chinensis steppe.