The Succession Stages Of Stipa Grandis + Leymus Chinensis Typical Steppe

Canopy cover, frequency and index value of 4 key species (Stipa grandis,Leymus chinensis,Cleistogenes songorica,Salsola cristatum) in Stipa grandis+ Leymus chinensis meadow steppe in Chenbarhu Banner in Inner Mongolia were analysized in this paper. The results showed: (1)The grassland succession can be divided into 4 seral stages: i.e. late succession, mid-seral, early intermediate and early succession; (2) the plant community biomass decreased as the degradation increased.(3) Different functional groups biomass changed in different way, and biomass of grass declined with the increasing grazing intensity. (4) There was no different on the species biodiversity among the 4 seral stages. (5) Litter cover has positive correlation with biomass and negative correlation with grassland seral stage.