Quantitative Classification and Ordination Analysis of Vegetation in Gexigou Nature Reserve,Yajiang

A community survey of Gexigou Nature Reserve in Yajiang was performed.Two-way indicator species analysis(TWINSPAN) and Detrended Correspondence Analysis(DCA)was respectively used to forest communities,shrub communities,and herbage communities.The vegetation of Nature Reserve was classified into twenty-one vegetation assemblages.The result of DCA reflected the relationship between environment gradient and distribution of communities.Water gradient was the leading factor for distribution of vegetation.Communities were different in different altitudinal gradient;there was clearly vertical zone in Nature Reserve.Aspect also was one factor which effected distribution of communities.Different communities scattered in the same altitudinal gradient because of different aspect,showing mosaic pattern.