为评估南水北调西线工程上线水源区大型底栖动物群落结构及环境驱动因子,于 2022 年7 月(汛期)和11 月(非汛期)开展监测采样工作.采用生物多样性指数和丰度-生物量比较曲线(ABC曲线)作为大型底栖动物群落特征参数,分析大型底栖动物群落在水源区的结构,并对其进行多元排序和Pearson相关性分析.结果表明:共采集45 种大型底栖动物,隶属于4 门5 纲10 目32 科44 属,其中优势种8 种,所有优势物种出现频率均大于50%,水源区大型底栖动物群落结构一致性较高;水源区Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数均值分别为4.01、1.68、0.61;多数采样区域大型底栖动物的ABC曲线呈纠缠态势,其丰度和生物量累积百分比的差值面积在0 附近波动,群落以小个头物种为主;优势种以耐污值低的敏感种类为主,说明河流几乎不受污染,水体清洁;pH值是影响水源区大型底栖动物群落结构的主要环境驱动因子.
To evaluate the structure of benthic macroinvertebrate communities and the environmental driving factors in the source area for the upper line of the South-to-North Water Diversion Project(West Route),monitoring and sampling work was carried out in July(flood season)and November(non-flood season)of 2022.Biodiversity index and abundance-biomass comparison curve(ABC curve)were used as characteristic parameters of benthic macroinvertebrate communities to analyze the structure in the water source area and to conduct multivariate ordination and Pearson correlation analysis.The results showed that a total of 45 species of benthic macroinvertebrates were collected,belonging to 4 phyla,5 classes,10 orders,32 families,and 44 genera,of which 8 were dominant species and had a frequency of occurrence greater than 50%.The consistency of the benthic macroinvertebrate community structure in the water source area was high.The mean values of Margalef richness index,Shannon-Wiener diversity index,and Pielou evenness index in the water source area were 4.01,1.68,and 0.61,respectively.The ABC curve in most sampling areas showed an entangled pattern,and the area of the difference between the cumulative percentage of abundance and biomass fluctuated near 0,with the community dominated by small-bodied species.The dominant species were mainly sensitive species with low pollution tolerance,indicating that the river was almost free from pollution and the water was clean.pH was the main environmental driving factor affecting the structure of the benthic macroinvertebrate community in the water source area.