漓江秋季大型底栖动物群落结构特征分析

Autumn macroinvertebrate community structure in Lijiang River

2009年8—9月,通过对漓江流域大型底栖动物进行详细调查,共鉴定大型底栖动物3门6纲24种,其中昆虫纲种类最多,腹足纲次之。以优势度指数大于0.02作为判别标准,判断出调查区域内全流域以及上中下游的优势种。调查结果表明:漓江大型底栖动物平均总密度与平均总生物量分别为682个/m2和152.77g/m2。两者均为下游最高、中游次之、上游最低。其Shannon-wiener多样性指数、Pielou均匀度指数和Marglef丰富度指数的平均值分别为2.37、0.61和6.01。并依照漓江上、中、下游3个江段150个采样点的数据作出丰度/生物量曲线,分析该曲线,认为漓江上游大型底栖动物群落处于未受干扰的状态;其他两个江段则均受到了轻度的干扰。

In order to have an insight into the macroinvertebrate community in response to the anthropogenic disturbance, ecological survey of the macroinvertebrate was made from August to September in 2009. A total of 24 species among 6 classes 3 phylum were collected, and the Insecta was the dominant group in the benthos, followed by the Gastropoda. Based on the dominant index, Y〉0.02 was taken as the judging standard. The dominant species in the whole river and different reaches were analyzed. The average total density and biomass of macroinvertebrate were 6g2ind./m2 and 152.77g/m2, separately, and the average density and biomass were highest in downstream, followed by midstream, upstream. The average value of Shannon-Wiener diversity index, Pielou＇s evenness index and Margalef＇s species richness were 2.37, 0.61, 6.01. In addition, the abundance/biomass curves based on the sampling result in different reaches were given. Upon analysis of the macroinvertebrate community structure by ABC curves, the macroinvertebrate community condition had not been affected in upstream and that was slightly disturbed in midstream and downstream.