Abstract:

To understand the resources of macrozoobenthos and the impact of step hydropower station upon the community structure and biodiversity of macroinvertebrates along Wujiang River in Guizhou section,the benthic fauna of 18 sampling sites were investigated.The diversity of benthic fauna was calculated by ShannonWiener diversity index.The results showed that in the natural river of Wujiang River, there were rich benthic species which dominanted by the arthropod species.The species richness and density of Sinan sampling plot was highest,the biodiversity of Yanhe secondbridge sampling plot was highest.Annelidmolluskarthropod were dominant community of complex communities,and the mollusks were dominant species.The construction of  step hydropower station decreased the differences in sedimentary environment,and the richness,density and diversity of benthic species,simplified the community types,and made the performance of dominant groups not obvious.The standing crops of the macroinvertebrates decreased with the operating time of the reservior.And oligochaetes and chironomids composed the main species composition.The results showed that the construction of step hydropower station had a negative impact on the benthic fauna species composition,density,diversity and community types.〖