Characteristic of spatial distribution and climate zone of natural grassland types in Qinghai

Based on the indexes of moisture and heat of QinghaiTibetan Plateau, the appropriate modified indexes were established. It was found that because of the climatic warming effect on QinghaiTibetan Plateau in recent half century, the upper limit temperature index in the hottest month of subfrigid zone and temperate zone on QinghaiTibetan Plateau increased 1 to 2 ℃; the lower limit of accumulative temperature (0 ℃) increased 50 ℃. According to the moisture status in Qinghai, 6 climatic zones were setup; meanwhile, 10 grassland types were grouped and fitted to these 6 zones. The relationship between grassland distribution and habitat characteristics (altitude, temperature and precipitation) was described. And the richness, biomass, height and coverage of grassland community were evaluated as well.