Study On Vegetation Spatial Heterogeneity Under Different Stocking Rate In Stipa Breviflora Desert Steppe

The Siziwangqi desert steppe is selected as an experimental field for this experiment, in order to ascertain the variation of species quantity and species diversity under different Stocking rate, field experiment and laboratory analysis are adopted for studying species composition, vegetation community feature and its diversity change. Meanwhile, the power function rule is used for studying the influence of different Stocking rate on grassland spatial heterogeneity, so as to know whether the power function rule can be applied for vegetation heterogeneity research in desert steppe, and to analysis the difference of vegetation spatial heterogeneity under different Stocking rate and the influence of different plants on the whole community heterogeneity. The major research results are as follows:1.With the increase of Stocking rate, the importance value of community species has changed for some degree in Inner Mongolia Stipa breviflora desert steppe, the importance value of some species declined because animals favor its good palatability, whereas those species that have bad palatability for animals increased, and the dominant species in the community haven’t changed, the community is stable.2.With the increase of Stocking rate, the height, density coverage and biomass of community species in Inner Mongolia Stipa breviflora desert steppe tend to decline successively, and significant difference is noticed. The diversity index of the community declined significantly, the homogeneity and diversity index also show decline trend, but the decline is not notable. Above mentioned situation relate to the poor antijamming capability of the whole community and the relatively less vegetation species in the desert steppe.3.Under different Stocking rate in Inner Mongolia Stipa breviflora desert steppe, the whole vegetation community has better spatial heterogeneity than random distribution, with the increase of Stocking rate, the spatial heterogeneity distribution of the whole vegetation community tend to increase. Moreover, the spatial heterogeneity of different plant population shows different variation under different Stocking rate, this relates to the biological characteristics of the plant themselves and the ecological adaptation measures of plant population against grazing pressure.