A PRELIMINARY STUDY ON BIOLOGICAL DIVERSITY AND FEA(?)OMMUNITIES IN ALPINE MEADOW AND ITS DETERIORATIVE RESULT—"(?)PATCH"
Li Xilai (Qinghai Animal Husbandry and Veterinary Medicine College,Xining 810003)
According to the deteriorative features of alpine meadow,the 6 grades"black soil patch"grassland were divided.The each grade species diversity and features of plant communities were studied respectively. The results showed that the indexes of species diversity(3.234)and evenness(1.115)of moderate deteriorative"black soil patch"(area of barren patch occupy 27.6%)were bigger than others.By increasing deteriorative grade to a high level,the area ratio of barren patch and the ratio of poisonous weeds had significantly increased(P0.01),but the dominance of Kobresia of original vegetation and underground living phytomass(30cm)had significantly decreased(P0.01),and the yield of communities in every grade grassland had not obviously changed.The dominances of Kebresia of"black soil patch"of the severe and extreme deteriorative grassland were 14% and 1% respectively,the underground living phytomas in 30cm soil layer were 1662.0g/m~2 and 1388.7g/m~2 resp.
【CateGory Index】： S812