The Study On Comparison Of Community Characteristics And Soil Ecological Stoichiometry At Different Vegetation Types In Typical Steppe Of Inner Mongolia

Inner Mongolia Plateau is the natural ecological barrier in northern China, studing on different of community in typical steppe studies can provide a scientific basis for grassland research in the future. In this study, comparing of communities characteristics and soil ecological stoichiometry of three different grassland communities in typical steppe of Inner Mongolia, three different communities including Leymus chinensis community and Stipa grandis community and Stipa krylovii community, sdudy on the characteristics of grassland communities, biodiversity, aboveground biomass and soil nutrient content, the stoichiometric ratio. The results indicated:1.Leymus chinensis community and Stipa grandis community and Stipa krylovii community mainly compose of perennial xerophytic pasture-based, including Gramineae, Leguminosae, Asteraceae and legumes. Leymus chinensis community have the most plant species, there are similar plant species between Stipa grandis community and Stipa krylovii community. The density of Leymus chinensis community is significant higher than that of Stipa grandis community and Stipa krylovii community, the cover of Stipa grandis which is in Stipa grandis community is large.2.The Margarlef index, Shannon-Wiener index, Simpson index, Pielou index of Leymus chinensis community are lower than the Stipa grandis community and Stipa krylovii community in every month. The uneven distribution of species and relative density of L. chinensis lead to low Margarlef index of Leymus chinensis community. Uniformity of is higher and the important value of the main species Stipa krylovii community is similar, so the higher of the index.3.With the soil depth, soil nutrient of Leymus chinensis community; Stipa grandis community and Stipa krylovii community reduces.The content of0-20cm soil layer nutrient is significantly higher than the content of40-60cm soil layer (P<0.05) under different vegetation, surface aggregation effect of Stipa grandis community stronger than Leymus chinensis community and Stipa krylovii community. Compare with the other soil nutrient, surface aggregation effect for P is not significant.4.Soil organic carbon content of Leymus chinensis community is significantly higher than the Stipa grandis community and Stipa krylovii community, the organic carbon content of the Stipa krylovii community is lowest. Soil total nitrogen and available nitrogen, Leymus chinensis community is significantly higher than the other two communities (p<0.05).5.N/P of soil of Leymus chinensis community and Stipa grandis community is lower, the two communities are affected by nitrogen constraints, Stipa grandis community affected by soil nitrogen constraints more severely, Stipa krylovii community limit by the nitrogen and phosphorus.C/N, Leymus chinensis community> Stipa grandis community> Stipa krylovii community the organic carbon content of the Leymus chinensis community is higher. There is no significant difference content of soil total phosphorus between Stipa grandis community and Leymus chinensis community, C/P of soil of Stipa grandis is lower, compare with C/P of soil of Leymus chinensis community, soil phosphorus of Stipa grandis communitiy is adequate.