银川平原内陆浅水湖泊底栖动物群落对疏浚工程的响应

Response of macroinvertebrate communities in inland shallow lakes in Yinchuan Plain to dredging projects

沙湖、鸣翠湖和柳溪湖是银川平原典型的内陆浅水湖,湖泊内源污染严重,自2015年起实施疏浚工程以实现内源治理,湖泊环境生态得到明显改善。为探究银川平原内陆湖泊底栖动物群落对疏浚工程的响应,分别于2015年(疏浚前)和2020年(疏浚后)在沙湖、鸣翠湖和柳溪湖共设置16个采样点进行底栖动物调查。结果表明:疏浚后沙湖底栖动物的平均密度和生物量低于疏浚前,鸣翠湖和柳溪湖的平均密度和生物量均高于疏浚前,疏浚前后湖泊的优势种和摄食功能群也发生很大变化。非度量多维标度排序(nMDS)结果表明,疏浚前后底栖动物群落结构存在显著差异,指示物种分析也表明了疏浚前后底栖动物群落的结构变化。Beta多样性分解结果表明,疏浚前后底栖动物beta多样性均以物种周转为主导,且疏浚工程增加了底栖动物beta多样性和物种周转对beta多样性的贡献率。研究明确了内陆湖泊底栖动物群落对疏浚工程的响应特征,为城市浅水湖泊生态治理和生物多样性保护提供了依据。

Shahu Lake,Mingcui Lake,and Liuxi Lake,which are typical inland shallow lakes in the Yinchuan Plain,are polluted by endogenous contaminants.Since 2015,dredging projects have been implemented to manage endogenous pollution,which has improved the ecological health of the lakes.To investigate the response of macroin-vertebrates in inland lakes in Yinchuan Plain to the dredging project,a total of 16 sampling sites were set up for field surveys in 2015(before dredging)and 2020(after dredging)in the three lakes.The results showed that the average density and biomass of macroinvertebrates in Shahu Lake were lower after dredging than those before dred-ging,while the average density and biomass in Mingcui Lake and Liuxi Lake were higher after dredging than those before dredging.The dominant species and feeding functional groups of macroinvertebrates changed greatly after dredging.Non-metric multidimensional scaling(nMDS)results showed significant differences in macroinvertebrate community structure before and after dredging.The indicator species analysis showed structural changes in the mac-roinvertebrate community before and after dredging.Results of beta diversity partitioning showed that the beta diver-sity of macroinvertebrates was largely contributed by species turnover both before and after dredging.The dredging projects increased beta diversity and the contribution rate of species turnover to the beta diversity.Our results clari-fied the characteristics of the macroinvertebrate community of inland lakes in response to dredging,and provided a basis for ecological management and biodiversity conservation of urban shallow lakes.