Community Types and Their Features of Alpine and Subalpine Meadow on Deqin County of Southeastern Tibetan Plateau

The study was conducted in Deqin County in the northeastern Yunnan Province in an effort to understand the present situation of the subalpine and alpine meadow. Community plot method was employed. 94 plots were investigated and their species composition, community coverage, and community structure were examined. The types and features of subalpine and alpine meadow were analyzed. The results displayed there are at least 20 community types of meadow existing in subalpine and alpine region of the Deqin County. Most types were on the way of degradation and obvious interactive substitution was found among those communities. Iris japonica community, Actium lappa community, and Stellera chamaejasme community were the most typical and poisonous types formed under the situation of meadow degradation seriously. There was average 8 species existing in one square meter and average coverage was 62.4%. The aboveground biomass was 4859 kg/hm 2 and average edible rate was 61.5%. An important finding is that the long_term high_intensity grazing increased community diversity but decreased species diversity in a community. Totally speaking the long term grazing regime existing lowered the value and ecological services of biodiversity in Deqin County, contributing to unsustainable development of alpine and subalpine meadow ecosystems.