基于底栖动物的城市内河水生态状况评价——以圭塘河为例

Water Ecological Evaluation of Urbanizing River Based on Macroinvertebrates: A Case of the Guitang River in Changsha City

圭塘河是长沙市唯一的一条城市内河,研究圭塘河的底栖动物及水生态现状对城市河流的生态管理及治理具有一定的指导意义。2016年5-7月对圭塘河的底栖动物及河流水质进行了野外调查,主要研究了圭塘河底栖动物的空间分布特征及群落多样性,所有采样点共鉴定底栖动物24科,其中软体动物4科、寡毛纲2科、水生昆虫13科、十足目3科、蛭纲2科、端足目1科。研究结果显示,圭塘河物种丰富度较低,从生物量来看,除S2外上下游段各点生物量较中游段各点明显偏少,至S10已降至0.054 6 g/m^2;从生物指数来看,S4~S7的各项指数较其他点明显增大,说明这一段栖息地环境得到改善。颤蚓科为圭塘河优势物种,数量百分比为85.37%,水质分析结果显示,圭塘河的水质为Ⅴ类水,颤蚓科的大量繁殖与其关系密切。在功能摄食类群上,圭塘河以直接收集者为主,其次为捕食者和刮食者。该河流的生态状况整体较差,但部分经河流生态治理工程治理后,栖息地环境和生态状况有所改善。

Guitang River is the only urbanized fiver of Changsha. The research benthic microinvertebate and water biology status of Guitang River has a guiding significance to the ecological management and treatment of urbanized river. Field investigations and sampling are conducted from May to July, 2016, to study the community structure and biodiversity of benthic macroinvertebrates in Guitang River. The investigation shows that the biodiversity for the Guitang River is low. A total of 24 taxa belonging to 24 families are identified. The taxa richness of middle reaches is larger than that of other reaches. The individual density of sampling sites in the middle reaches is more than other sampling sites. The density of SIO is the lowest of 0.054 6 g/m2. Based on the biodiversity indices, all of the indices of $4-$7 are more than other sampling sites, showing that the habitat of this section has been improved. Gastropoda （85.37% of the sum） is the dominant species of Guitang River. Based on the macroinvertebrate functional feeding groups, there are 4 groups in the Guitang River, and the main functional feeding group is collector-gatherer, secondly, predator and scrapper. The ecological situation of Guitang River is less satisfactory. The habitat environment and ecological situation are improved after the implement of fiver ecological control engineering.