Quantitative classification and ordination of Jinping hydropower station,Sichuan Province,China

A survey of the Dahe Bay vegetation in Jin-ping cascade hydropower station setting along the river stream in Sichuan province,China,was performed.A total of 132 plant species and 4 environmental factors in 50 sample quadrats were recorded.Assemblages of Jin-ping Dahe Bay were classified using two-way indicator species analysis(TWINSPAN),ordinating by detrended correspondence analysis(DCA).Seven vegetation assemblages were divided by TWINSPAN classification,in which Pouzolzia elegans shrub grassland was the dominant community in this area.The DCA two-dimension plot based on the TWINSPAN classified the samples into six ecotypes.On the horizontal axis the altitude decreased gradually from left to right,while the vertical axis saw the slope increased down to up.TWINSPAN classification showed explicit distribution scope in DCA ordination plot,and this could better reflect the relationships between communities and environmental factors when combined with TWINSPAN quantitative classification.