Plant community diversity of the city parks of Hangzhou

By typical sampling method,the species composition,the community structure and the species diversity index of plant community in the city parks of Hangzhou were analyzed and compared.The results showed that there were abundant plants species and recorded 44 families,79 genera and 120 species in the city parks of Hangzhou.In terms of species richness(S),Shannon-Wiener diversity(H′) and Simpson diversity index(D),ground shrub layer was the highest,followed by the arbor layer,small-arbor and shrub layer,the herb layer;in terms of the Pielou evenness index(J) and Alatalo evenness index(Ea),arbor layer was the highest.Compared with the natural community,arbor layer had comparatively rich species,herb layer had fewer species and shrub layer had very few regeneration seedlings.There were three types of community structure.TypeⅠwas arbor-herb(small arbor and shrub-herb);type Ⅱ was arbor-shrub-herb(arbor-small arbor and shrub-herb);type Ⅲ was arbor-small arbor and shrub-shrub-herb.In terms of species richness(S),Shannon-Wiener(H′),Pielou(J) and Alatalo(Ea) index,ⅢⅡⅠ;in terms of Simpson(D) index,ⅢⅠⅡ.Type Ⅲ was more identical to the natural community;while typeⅠhad little identity to the natural community.[Ch,3 tab.20 ref.]