Species Diversity of the Wetland Communities in the Natural Reserves of Shanxi

The species diversity of wetland plants communities from 36natural reserves of Shanxi was studied by the diversity indices including species richness index(R),Simpson index(D),Shannon-Weaver diversity(H')and evenness index(E1)on the basis of field investigation.The results indicated that the 315 samples were divided into 18associations by TWINSPAN.The average Rwas between 1-4.119,the average H′was between 0-1.165,the trends of both two indices were similarity.The average H′of the herbaceous plant community was small,and this suggested that the diversity level of wetland plant communities in the natural reserves of Shanxi was lower.The average E1 was between 0.17-0.957.The two extreme values,the largest and smallest,were both from aquatic plant community,while the average E1of the other community of hygrophytes and hygro-mesophytes was in the middle.Among the 36natural reserves,the average Rof Sushui River Source Nature Reserve was the highest,while in that of Mian Mountain Nature Reserve was the lowest(R=1.5).The average H′was between 0.335-1.617.In general,the diversity index of the wetland plant communities of the natural reserves in south Shanxi was higher than that in the central and north Shanxi.E1was between 0.501-0.984.There was a positive correlation between the species richness index,evenness index and diversity index.