城市化对河流大型底栖动物群落的影响研究进展

城市化可以引发一系列"城市溪流综合症",对河流健康造成巨大胁迫。大型底栖动物是河流生态系统的重要组成部分,对环境因子敏感,能够较好的反映流域环境的变化。城市化后,流域人口增加,建设用地比例上升,入河污染物浓度和总量增多,底栖动物中敏感物种比例降低甚至消失,寡毛类、摇蚊等耐污物种成为优势类群;群落多样性显著降低,并且一般与城市化强度成负指数关系;底栖动物总密度普遍大幅度增加,收集者为主要摄食功能群;不透水地表面积比例的增加改变了流域自然的水文过程,群落组成的季节波动减弱,但密度的波动增大;次级生产力明显增加,食物网趋于简化。初步分析了城市化过程中水质污染、水文、生境破坏、流域土地利用等因素影响底栖动物群落的规律和机制,并且根据国内外研究现状提出了进一步研究的方向,以期为我国城市河流生态学研究、流域生态管控和河流生态系统修复提供科学依据。

Advances in research on the influence of urbanization on stream benthic macroinvertebrate communities

Urbanization imposes considerable stress on river health and leads to the so-called "Urban Stream Syndrome." As an important components in running water ecosystems, benthic macroinvertebrate is sensitive to environmental change and can reflect variations in watershed environments. As a consequence of rising of populations and percentage of construction area associated with increasing urbanization, there have been marked increases in the total amount and concentration of pollution discharged into rivers. As a result, populations of sensitive species either disappear or are reduced in size, whereas Oligochaeta and Chironomidae become the dominant taxa. Biodiversity is decreased and shows a negative and exponential relationship with the intensity of urbanization. Total density of stream biota increases significantly, and collectors become the dominant functional feeding group. The increase in impervious area changes the hydrologic processes of watersheds. Seasonal dynamics of the community component is decreased, whereas the variation in density is increased. Secondary productivity increases, and food web is reduced in complexity. The present paper summarizes the principles and mechanisms underlying the effects of water pollution, hydrology, stream habitat, and land use on stream macroinvertebrates. Further research on urban stream macroinvertebrate ecology is also proposed. It is hoped that this review will promote urban stream ecology research and provide a scientific basis for watershed ecological management and river restoration.