Distribution of biomass and diversity of Stipa bungeana community to climatic factors in the Loess Plateau of northwestern China

Based on 28 year field data of Stipa bungeana community in arid, semi-arid, semi-humid areas of the Loess Plateau of Northwestern China, we studied species diversity and above ground biomass of S. bungeana community, analyzed the responses of above ground biomass to climate in different areas, and built a model of relationship between biomass and climatic factors. Results showed that there were significant differences for species diversity and above ground biomass among different sampling area. The species diversity range of S. bungeana was from 8.5 - 30.8 (ind/m(2)), and above ground biomass range was from 407.3 - 817.3 (g/m(2)) among studied area. The optimal distribution altitude range for S. bungeana is 1400 - 2000 m in arid area, 1200 - 1900 m in semi-arid area, and 600 - 1600 m in semi-humid area. Results also showed that the growth of S. bungeana was affected by different climatic factors, with rainfall as the major factor. Meanwhile, there was a close relationship between monthly biomass and rainfall during the growth stage. The models of monthly biomass and climate were built to compare the results and reveal the relationship between climatic factors and the growth of S. bungeana community.