Effects Of Grazing On Plant Traits And FU Nctional Groups And Productivity In Stipa Krylovii Steppe

Stipa krylovii steppe is important ecological type of Eurasia temperate cli mate regions. It’s significant to the development of the grassland ecology scien ce, for research of grazing on plant traits, functional groups and species divers ity in Stipa krylovii steppe. In this paper, plant traits, plant functional groups, productivity and species diversity in different grazing gradient plots of stipa kr ylovii steppe in Kelulun basin were studied. It’s aimed to provide theoretical b asis of study with grassland ecology.The plant traits with different life form had no significant difference in St ipa krylovii steppe. Grazing disturbance is one of the ways to influence on pla nt traits, and plant leaf traits actually reflect the adaptability of plants to the e nvironment. However, the relationships between plant traits were strongly corre lated. Across the grazing gradient, the phosphorus content (LPC) and the ratio of nitrogen and phosphorus (N/P) in the heavy grazing treatment were signifi cantly different from those in the moderate grazing and the light grazing treat ments. For functional groups by the classification of life forms, grazing disturb ance effected significantly on LPC and N/P in the perennial weeds, which sho wed that perennial weeds were sensitive to grazing treatments, and plant nutrie nt utilization strategy was changed by heavy grazing.The perennial forbs had a significant advantage in light and moderate gra zing areas but annual or biennial herb had an obvious advantage in heavy gra zing areas in life form functional groups. Perennial grasses had the absolute su periority in light grazing areas from the distribution of biomass perspective. X erophyte had the absolute superiority in all of the light, moderate and heavy g razing areas in moisture ecological functional groups. The distribution of xerop hyte is biggest under light grazing areas from the distribution of biomass pers pective.There are differences between the effects of different grazing intensity, over grazing significantly reduced the community productivity and species diversity. At the same time, species richness and Shannon-Wiener index was highest in moderate grazing area at community level. With the increasing grazing intensi ty showed a single peak type curve characteristics and accord with "intermedia te disturbance" hypothesis. Thus, moderate grazing is the effective way to prot ect healthy function of grazing ecosystem and maintain development of grassla nd ecology.