Three Kind Of S.Grandis Community Research In Dynamic Of Inner Monggolia Xilingol League Area

Grassland ecosystem is one of the type has a wide distribution on the earth.Inner Mongolia grassland is a natural ecological barrier in north China.The Xilingol grassland is mainly as one of the natural grassland in Inner Mongolia.This article through to research three kinds of S.grandis community of Inner Mongolia including S.krylovii community, S.grandis community and Baikal s.grandis community analysis of five consecutive years in 2009-2013. The results indicated:1. A,biennial plants are sensitive to summer precipitation in S.krylovii community.It may produce some inhibition to growth of the bunch grass in wet years.2. The species richness of Baikal s.grandis community is the highest. The species richness of S.krylovii community is less and the species richness of S.grandis community is lowest. The Shannon-wienner index and Simpson index of S.krylovii community is relatively stable in 5 consecutive years.The Shannon-wienner index、 Simpson index and Pielou index of S.grandis community is lower except of special years. The Shannon-wienner index、Simpson index and Pielou index of S.grandis community is lowest in the year of 2013.3. The relative density/biomass of L.chinensis in S.krylovii community and Baikal s.grandis community were significantly negative correlation with Pielou evenness index(P<0.01); The relative density/biomass of L.chinensis in S.grandis community was negative correlation with Pielou evenness index(P<0.05);4. Aboveground biomass of S.krylovii community was significant positive correlation with annual precipitation (P<0.01) and significantly negative correlation with annual average temperature(P<0.01); S.grandis community and Baikal s.grandis community has no such correlation(P<0.1).5. Aboveground biomass of three kinds of s.grandis community was significantly correlation with Shannon-wienner index (P<0.05).6. The species richness of S.krylovii/Baikal s.grandis community was positive correlation with annual precipitation (P<0.05) and significantly negative correlation with annual average temperature(P<0.01);S.grandis community has no such correlation(P<0.1).