State Key Laboratory of Eco-hydraulic in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, 710048, Shaanxi, China; CAS Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
State Key Laboratory of Eco-hydraulic in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, 710048, Shaanxi, China.
Environ Pollut. 2022 Aug 1;306:119410. doi: 10.1016/j.envpol.2022.119410. Epub 2022 May 4.
The accelerated eutrophication of freshwater lakes has become an environmental problem worldwide. Increasing numbers of studies highlight the need to incorporate functional and phylogenetic information of species into bioassessment programms, but it is still poorly understood how eutrophication affects multiple diversity facets of freshwater communities. Here, we assessed the responses of taxonomic, phylogenetic and functional diversity of benthic macroinvertebrates to water eutrophication in 33 lakes in the Yangtze River floodplain in China. Our results showed that macroinvertebrate assemblage structure was significantly different among four lake groups (river-connected, macrophyte-dominated, macrophyte-algae transition, and algae-dominated). Three taxonomic, two phylogenetic and two functional diversity indices were significantly different among the lake groups. Except for the increasing trend of Lambda, these metrics showed a clear decreasing trend with increasing levels of eutrophication, with highest values detected in river-connected and macrophyte-dominated lakes, followed by macrophyte-algae transition lakes and algal-dominated lakes. Although differing in the number and identity of key environmental and spatial variables among the explanatory models of different diversity indices, environmental factors (eutrophication-related water quality variables) played more important role than spatial factors in structuring all three facets of alpha diversity. The predominant role of environmental filtering can be attributed to the strong eutrophication gradient across the studied lakes. Among the three diversity facets, functional diversity indices performed best in portraying anthropogenic disturbances, with variations in these indices being solely explained by environmental factors. Spatial factors were mostly weak or negligible in accounting for the variation in functional diversity indices, implying that trait-based indices are robust in portraying anthropogenic eutrophication in floodplain lakes. However, variation in some taxonomic and phylogenetic diversity indices were also affected by spatial factors, indicating that conservation practitioners and environmental managers should use these metrics with caution when providing solutions for addressing eutrophication in floodplain lakes.
淡水湖泊的加速富营养化已成为全球范围内的一个环境问题。越来越多的研究强调需要将物种的功能和系统发育信息纳入生物评估计划，但对于富营养化如何影响淡水群落的多个多样性方面仍知之甚少。在这里，我们评估了底栖大型无脊椎动物的分类、系统发育和功能多样性对中国长江流域平原 33 个湖泊富营养化的响应。我们的研究结果表明，大型底栖无脊椎动物群落结构在四个湖泊群（河流连通、大型植物为主、大型植物-藻类过渡和藻类为主）之间存在显著差异。三个分类、两个系统发育和两个功能多样性指数在湖泊群之间存在显著差异。除了 Lambda 的增加趋势外，这些指标随着富营养化程度的增加呈现出明显的下降趋势，在河流连通和大型植物为主的湖泊中检测到的数值最高，其次是大型植物-藻类过渡湖泊和藻类为主的湖泊。尽管在不同多样性指数的解释模型中，环境和空间变量的数量和身份不同，但环境因素（与富营养化有关的水质变量）在构建 alpha 多样性的所有三个方面中比空间因素发挥了更重要的作用。环境过滤的主导作用可以归因于研究湖泊之间强烈的富营养化梯度。在这三个多样性方面，功能多样性指数在描绘人为干扰方面表现最佳，这些指数的变化仅由环境因素解释。空间因素在解释功能多样性指数的变化方面大多较弱或可以忽略不计，这意味着基于特征的指数在描绘平原湖泊人为富营养化方面具有稳健性。然而，一些分类和系统发育多样性指数的变化也受到空间因素的影响，这表明保护实践家和环境管理者在为解决平原湖泊富营养化提供解决方案时应谨慎使用这些指标。
