Study on community structure of macro-invertebrates in tributaries of Three Gorges Reservoir
三峡库区支流底栖动物群落结构研究

Abstract: The macro-invertebrates were collected in 26 major tributaries of Three Gorges Reservoir area in April 2010. 97 species were recorded, including 78 species of aquatic insects, 10 species of mollusks, 6 species of Oligochaeta. Ephemeridae sp.,Ephemerellidae sp.,Baetis sp. Caenis sp. Choroterpes sp. Ecdyonurus sp. Othacladius sp.and Thieneminimyia sp.were common species. The average density was 673.22ind./m2 while the average biomass was 9.9398 g/m2.The result of MDS analysis showed that the sites of Yulinhe River,Longxihe River,Changtanxi River and Jialingjiang River were far away from the sites of other 22 rivers.The clustering analysis of species composition showed that there was high species similarity between Baolonghe River and Tongxihe River,as well as Tongzhuanghe River and Dalinghe River,zhaxihe River and Huangjinhe River,Modaoxi River and Xiaojiang River,Daxihe River and Guanduhe River,Longhe River and Lixiangxi River,Yulinghe River and Qijiang River,Longxihe River and Changtanxi River. The result of biodiversity analysis showed that Shannon-wiener indexes ranged from 0.6365 to 2.9329 with mean of 1.6120,while Margalef indexes ranged from 0.6266 to 5.3074 with mean of 2.2976. Key words: Three Gorges Reservoir; Macro-invertebrates;species; Biomass; Biodiversity; Species similarity