城市人工浅水湖泊底栖动物群落结构及影响因素分析

Community Structure and Influencing Factors of Benthic Macroinvertebrates in Artificial Urban Shallow Lakes

探讨梅溪湖底栖动物群落结构及其影响因素,为城市人工湖泊水生态系统修复后的运营维护管理提供理论依据。2020-2021年在梅溪湖设置14个采样站位(敞水区7个,滨岸带7个),按季节开展底栖动物调查。研究结果表明,梅溪湖底栖动物种类达75种,滨岸带种类数高于敞水区。整个湖区全年优势种为米虾(Caridina sp.)、铜锈环棱螺(Bellamya aeruginosa)、椭圆萝卜螺(Radix swinhoei)、大脐圆扁螺(Hippeutis umbilicalis)、霍甫水丝蚓(Limnodri-lus hoffmeisteri)和沼虾(Macrobrachium sp.)。敞水区和滨岸带群落结构存在显著差异,除霍甫水丝蚓外,全年优势种是导致2个区域群落结构差异的主要分类单元。梅溪湖底栖动物现存量和多样性季节间无显著差异,但敞水区和滨岸带之间差异显著,滨岸带远高于敞水区,表明水生植物群落的构建有利于底栖动物种群的壮大和多样性的提高。CCA结果表明,氨氮(AN)和营养水平(TLI)对敞水区和滨岸带的底栖动物群落结构均有较大影响。CoIA分析结果显示,米虾、大脐圆扁螺、铜锈环棱螺、沼虾、椭圆萝卜螺等物种与环境因子存在较为密切的联系,这些物种可以作为梅溪湖水环境条件变化的指示种。合理控制梅溪湖底栖动物群落结构,并维持较高的多样性水平,可有效促进其生态系统的正常运转。

Meixi Lake is a recently constructed artificial shallow lake in the Xiangjiang New Area of Changsha,Hunan Province,serving multiple ecological functions and is playing an important role in environmental improvement and economic development of the area.Since its formation,macroinvertebrates have played a crucial role in the developing ecology of the lake.In this study,we explored and analyzed the macroinvertebrate community and its influencing factors in Meixi Lake after an ecological treatment project implemented during 2017-2018.Our aim was to provide theoretical and technical support for the restoration and management of water ecosystems in urban artificial lakes.In November 2020,January,April and July 2021,quantitative and qualitative samples of macroinvertebrates and water samples for water quality analysis were collected at 14 sites in Meixi Lake,including 7 sampling sites in the open water area and 7 in the littoral zone.A total of 75 macroinvertebrate species were identified during the four investigations in Meixi Lake,with the dominance of Caridina sp.,Bellamya aeruginosa,Radix swinhoei,Hippeutis umbilicalis,Limnodrilus hoffmeisteri,and Macrobrachium sp.throughout the year.Species richness in the littoral zone(61 species)was higher than that in the open area(42 species).There were significant differences in the macroinvertebrate community structure between the littoral zone and open water,attributed to the dominant species,except for Limnodrilus hoffmeisteri.There were no significant seasonal differences in the macroinvertebrate density,biomass and community diversity,but the differences between the open water and littoral zone were significant.They were much higher in the littoral zone,indicating that construction of the aquatic plant community increased macroinvertebrate population growth and community diversity.Canonical correlation analysis of the sampling sites and environment shows that both ammonia nitrogen and the comprehensive trophic level index(TLI)had a significant impact on the macroinvertebrate communities in both the open water and the littoral zone.CoIA analysis shows that species like Caridina sp.,Hippeutis umbilicalis,Bellamya aeruginosa,Macrobrachium sp.,and Radix swinhoei,were closely related to environmental factors,which could serve as effective indicator species to water environment conditions in Meixi Lake.In conclusion,the macroinvertebrate community structure in Meixi Lake is reasonable and controllable,and community diversity maintains at a relatively high level,ensuring normal functioning of the aquatic ecosystem.