乌江梯级电站开发对大型底栖无脊椎动物群落结构和多样性的影响

为了解乌江贵州段的底栖动物资源现状以及梯级电站开发对底栖动物群落结构和多样性的影响，对18个断面的底栖动物进行了调查。底栖动物多样性通过Shannon Wiener多样性指数进行计算。结果显示：自然河段中，底栖动物物种丰富，以节肢动物占优势，物种丰富度和密度均以思南断面最高，生物多样性则以沿河二桥断面最高；群落类型复杂，环节动物 软体动物 节肢动物为优势群落，软体动物为群落中的优势类群。梯级水库的修建使底质环境差异变小，底栖动物物种丰度、密度和生物多样性降低，群落类型趋于简单，优势类群表现不明显，并且水库建成的年代越久,底栖动物的丰度、密度就越低,群落的组成类群就越少，物种组成以寡毛类和摇蚊类为主。研究表明,梯级电站的修建对底栖动物的物种组成、密度分布、多样性、群落类型等都造成了负面影响。〖

EFFECTS OF STEP HYDROELECTRIC EXPLOITS ON COMMUNITY STRUCTURE AND BIODIVERSITY OF MACROINVERTEBRATES IN WUJIANG RIVER

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.〖