Classification and Ordination of Ancient Camellia sinensis Communities and its Species Diversity in Xining,Leibo County

Based on the ecology investigation in Xining of Leibo County,studies were made of the distribution regions of wild Camellia sinensis Communities.Classification and Ordination of 37 vegetation plots(20 m×20 m) were investigated by DCA classification analysis.Species diversities of different spaces were analyzed by richness index(R),Simpson index(D),Shannon-wiener index(H) and Alatalo evenness index(E).The results showed that the wild C.sinensis communities were classified into 6 types by DCA,including ⅠC.sinensis + Quercus serrate + Castanopsis platyacantha communities,ⅡC.sinensis + Castanopsis fargesii + Cyclobalanopsis oxyodon communities,ⅢC.sinensis + Quercus aliena var.acuteserrata + Quercus fabri communities,ⅣC.sinensis + Cryptomeria fortune + Toona ciliate communities,ⅤC.sinensis + Betula luminifera + Juglans cathayensis communities,and ⅥC.sinensis + Alnus nepalensis + Sassafras tzumu communities.Most of them belonged to mixed evergreen and deciduous forest,some of them were evergreen broad-leaved forest or man-made Cryptomeria fortune forest.The results of DCA clearly reflected the distribution range of various community types,and DCA indicated the influences of site factors on the distribution pattern of community types and species.Based on the community similarity and stability,the chief protective measures for C.sinensis included in-situ conservation,avoiding human disturbance and strengthening the research on the artificial breeding.