中文摘要：

2006年4月至2007年3月，对清江流域上游一二级支流——叹气沟河的大型底栖动物群落结构进行了深入研究，并利用生物指数对河流水质进行了评价．结果表明，共采集到大型底栖动物82种，其中水生昆虫7目、27科、45属、70种．群落表现出明显的时空特点，具边缘效应的第2采样点物种最丰富，4月份物种最多，达61种；群落春季的多样性最高，依次为夏季、冬季、秋季；各微生境中共有种占据优势，物种相似性均大于60％；功能摄食群则以收集者占优，共计达55种．群落密度在4月份达到最大，为3293ind．／m2；而生物量则在12月份达到最大，为163g／m2．采用Shannon多样性指数、生物指数和科级水平生物指数对叹气沟河水质评价的结果是该河流水质比较清洁．

英文摘要：

The community structures of macrozoobenthos and bioassessment of water quality in a second order river-Tanqigou stream of Qingjiang River Basin were investigated from April 2006 to March 2007. Altogether 82 species of macroinvertebrates were collected, among which aquatic insects were 70 species, belonging to 45 genera in 27 families under 7 orders. The community structure exhibited an obvious spatial and temporal variations. Site $2 with fringe effect possessed the largest number of species, and most of the macroinvertebrates presented in April with 61 species sampled, more than those in other months. Over 60% of the collected species could inhabit in the six types of microhabitats. Biodiversity in spring was the largest, and followed summer, winter and fall in rank. The density of the community reached its peak in April at 3293ind./m2, while biomass attained its peak in December at 163g/m2. The water quality was bioassessed with Shannon-Weaner diversity, Biotic Index and Family Biotic Index, and totally it was fairly clean during the sampling period. Considering the coincidence with physical-chemical parameters, BI and FBI bioassessment methods were fitter to apply in this region.