Effects Of Stocking Rate On The Functional Traits Of Four Dominant Species In Desert Steppe

Protecting desert steppe has very important role in maintain biodiversity of grassland ecosystem,water conservation,greenhouse gas mitigation,etc.As the most economical and universal way of grassland utilization in desert grassland.grazing affected the composition and function of grassland productivity,process and pattern of the entire ecosystem.Four dominant species(Stipa breviflora,Cleistogenes songorica,Artemisia wormwood and Artemisiaas)was used as the research object.The response of functional traits including plant height(PH),single plant weight(SPW),Leaf length(LL),leaf area(LA),specific leaf area(SLA),leaf nitrogen content(LNC),and leaf carbon content(LCC)to stocking rate were analysed.The relationship between plant funcitional tarits and productivity,soil chemical property were also analysed,The pourse is to provides theoretical basis for stimpulate a reasonable stocking rate,protecting the biodiversity and grassland sustainable development in this area.The results showed:(1)The functional tarits of the four dominant species decreased with the increase of stocking rate.The functional traits of the CK showed the maximum value,while HG showed the minimum value.The maximum functional traits values appeared in August of all the four species.(2)There was a significant correlation between plant height,single plant weight,leaf length and leaf area in functional traits.Plant height,plant weight and leaf length were significantly correlated with aboveground biomass,and leaf traits and leaf element contents were significantly correlated with soil properties.(3)Compare to CK,plant height,plant weight,leaf length,leaf area and SLA were considered as sensitive traits for the grazing rate,and having greater variabilitythan than of leaf N content,leaf C content and leaf C/N,which having small variability and considered as inert traits.Among the four species,Artemisia frigida had the highest coefficient of variation and plasticity,Stipa breviflora had the lowest coefficient of variation and plasticity.