常州地区太湖流域上游水系大型底栖无脊椎动物群落结构特征及其与环境的关系

Characteristics of Benthic Macroinvertebrates Communities in Relation to Environment in Upper Reaches of the Taihu Lake Watershed in Changzhou Area,China.

2003年8月采用半定量采样法调查了常州地区太湖流域上游南河、运南、运北和洮滆水系29个样点的大型底栖无脊椎动物群落多样性,共获得113种大型底栖无脊椎动物,其中,腹足纲18种,瓣鳃纲10种,寡毛纲8种,蛭纲4种,甲壳纲6种,昆虫纲67种。优势种为霍甫水丝蚓(Limnodrilus hoffmeisteri)和梨形环棱螺(Bellamya purificata)。该群落平均密度为658 m-2,其中,霍甫水丝蚓密度最高,达400 m-2。观山桥样点大型底栖无脊椎动物群落多样性最高,群落物种数、Shannon-Wiener多样性指数、均匀度和生态优势度分别为54,4.36,0.76和0.08。综合分析结果表明,群落多样性从高到低排序依次为南河水系、洮滆水系、运南水系、运北水系.出现频率在15%以上的24个物种与6种环境因子之间的典范对应分析(CCA)结果显示,总氮、总磷和溶解氧对该地区大型底栖无脊椎动物群落多样性的影响较大。

Benthic macroinvertebrates assemblages were collected from 29 sites in the upper reaches of the Taihu Lake watershed, i.e. the Nanhe, Yunnan, Yunbei and Taoge water systems, in Changzhou area of China in 2003. A total of 113 species were found including 18 species in Gastropoda, 10 speices in Lamellibranchia, 8 species in Oligochaeta, 4 species in Hirudinea, 6 species in Crustacean and 67 species in Insecta, with Limnodrilus hoffmeisteri and Bellamya purificata being the dominant species. The average density of the communities was 658 m^-2 with L. hoffme/ster/being the highest, i.e. 400 m^ -2 Among the 29 sampling sites, Guanshanqiao was the highest in benthic macroinvertebrate diversity and its species richness, Shannon-Wiener diversity, evenness and ecological dominant index was 54, 4.36, 0. 76 and 0.08, respectively. In terms of benthic macroinvertebrate diversity, the 4 water systems were in the order of Nanhe 〉 Taoge 〉 Yunnan 〉 Yunbei. CCA analysis of the 24 species that were more than 15% in occurrence frequency and 6 environmental factors showed that total nitrogen, total phosphorus and dissolved oxygen were the major factors influencing distribution of benthic macroinvertebrates in the research area.