【摘要】 长江下游近河口的平原河网是连接太湖与长江的重要水文通道，其复杂的水系格局和多样的栖息地类型为水生生物多样性的维持提供了重要支撑。然而，长期高强度的城市化使河网系统承受多重干扰，导致结构失衡与生态功能退化。目前该地区河流大型底栖动物的研究有限，水质综合评价缺乏。研究基于2021年对长江三角洲典型河网24条代表性河流(段)的调查，分析底栖动物多样性空间格局，关键驱动因子及生态健康状况。依据地理位置，将调查河段划分为长江区、城中区和太湖区。共记录底栖动物3门7纲20目40科80属100种，包括水生昆虫41种，软体动物28种，环节动物24种和软甲类7种。太湖区物种数(76种)>长江区(55种)>城中区(52种)。底栖动物平均密度为1 297.72±1 273.87 ind./m~2。优势种为霍甫水丝蚓(Limnodrilus hoffmeisteri)、克拉泊水丝蚓(Limnodrilus claparedeianus)、二叉摇蚊(Polypedilum sp.)、大螯蜚(Grandidierella sp.)和铜锈环棱螺(Bellamya aeruginosa)。太湖区和长江区的物种多样性指数显著高于城中区，且三个区群落结构差异显著。营养盐指数、水草密度、水深及pH是影响底栖动物群落结构的关键因子。该河网健康状况整体处于中等水平(Q_R=0.54),太湖区(0.58)优于长江区(0.54)和城中区(0.51)。研究可为长江三角洲水生生物的科学保护与管理提供科学依据。更多还原

【Abstract】 The plain river network in the lower reaches of the Yangtze River, located near the estuary, serves as an important hydrological corridor connecting Taihu Lake and the Yangtze River. Its complex water system and diverse habitat types provide crucial support for the maintenance of aquatic biodiversity. However, long-term and intensive urbanization has imposed multiple disturbances on the river network, leading to structural imbalance and ecological functional degradation. Currently, research on macroinvertebrates in this region has remained limited, and comprehensive ecological assessments are still lacking. In this study, we investigated 24 representative river reaches within the typical river network of the Yangtze River Delta in 2021 to examine the spatial patterns of macroinvertebrate diversity, identify key driver factors, and assess ecological health conditions. Based on geographic location, the sampling sites were classified into the Yangtze River area(YRA), the central area(CA), and the Taihu Lake area(TLA). A total of 100 species of macroinvertebrates were recorded, belonging to 3 phyla, 7 classes, 20 orders, 40 families, and 80 genera, including 41 species of aquatic insects, 28 mollusks, 24 annelids, and 7 crustaceans. The species richness was highest in the Taihu Lake area(76 species), followed by the Yangtze River area(55) and the central area(52). The average density of macroinvertebrates was 1297.72 ± 1273.87 ind./m~2. The dominant species were Limnodrilus hoffmeisteri, Limnodrilus claparedeianus, Polypedilum sp., Grandidierella sp. and Bellamya aeruginosa. Diversity indices were significantly higher in the Taihu Lake and Yangtze River areas than in the central area, and the community structures differed markedly among the three areas. Nutrient index, macrophyte density, water depth, and pH were identified as the key environmental factors shaping macroinvertebrate community composition. The overall ecological health of the river network was classified as moderate(Q_R = 0.54), with the Taihu Lake area(0.58) showing better conditions than the Yangtze River area(0.54) and the central area(0.51). This study provided scientific foundation for the conservation and management of river biodiversity in the river networks of the Yangtze River Delta.更多还原