Effects of grazing intensity on species diversity and structure of meadow steppe community

The Stipa baicalensisLeymus chinensis meadow was classified into light, moderate and heavy degradation plots according to the different degradation degrees caused by grazing. The plant community characteristics and diversity index in each plot were measured. Results showed that along with the increasing of grazing intensity, the total aboveground yield of community and middlexerophytes kept similar decreasing trend. That of mesophyte increased first and then decreased but xerophyte showed an increasing tendency. S. baicalensis and L. chinensis were the dominant species and showed a decreasing trend. Species richness index increased first and then decreased. The index of diversity and evenness kept increasing, but the dominance index was contrary.