Species composition of a Leymus chinensis+forbs community and standing biomass under overgrazed environment

The soils and communities of Leymus chinensis + forbs meadow steppe in typical steppe region changed due to grazing intensities were studied. The results indicated that the intensity of the topsoil increased significantly and the topsoil water content did not change with increasing of grazing pressures. The standing biomass of high grazing pressure was higher than that of the moderate grazing intensity, but it was lower than that of low grazing pressure. There was a significant difference between the standing biomass of low grazing pressure and that of either moderate grazing pressure or high grazing pressure. Their successions were L. chinensis + forbsL. chinensis + Cleistogenes squarrosa + Carex duriusculaC. squarrosa + Stipa grandis + Agropyrom michnoiC. squarrosa + Potentilla acaulis + Artemisia frigida. So the plant composition in degradation grasslands was influenced by the way and intensity of the utilization, and restricted by the habitat conditions. The succession series of the L. chinensis + forbs meadow steppe in typical steppe region was between the typical steppe and meadow steppe.