Senckenberg Research Institute and Natural History Museum Frankfurt, Department of River Ecology and Conservation, Clamecystr. 12, 63571 Gelnhausen, Germany; Goethe University Frankfurt, Faculty of Biology, Institute of Ecology, Evolution and Diversity, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany.
Goethe University Frankfurt, Faculty of Biology, Department of Aquatic Ecotoxicology, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany.
Sci Total Environ. 2023 Jun 20;878:162952. doi: 10.1016/j.scitotenv.2023.162952. Epub 2023 Mar 21.
Multiple stressors affect freshwater systems and cause a deficient ecological status according to the European Water Framework Directive (WFD). To select effective mitigation measures and improve the ecological status, knowledge on the stressor hierarchy and individual and joined effects is necessary. However, compared to common stressors like nutrient enrichment and morphological degradation, the relative importance of micropollutants such as pesticides and pharmaceuticals is largely unaddressed. We used WFD monitoring data from Saxony (Germany) to investigate the importance of 85 environmental variables (including 34 micropollutants) for 18 benthic invertebrate metrics at 108 sites. The environmental variables were assigned to five groups (natural factors, nutrient enrichment, metals, micropollutants and morphological degradation) and were ranked according to their relative importance as group and individually within and across groups using Principal Component Analyses (PCAs) and Boosted Regression Trees (BRTs). Overall, natural factors contributed the most to the total explained deviance of the models. This variable group represented not only typological differences between sampling sites but also a gradient of human impact by strongly anthropogenically influenced variables such as electric conductivity and dissolved oxygen. These large-scale effects can mask the individual importance of the other variable groups, which may act more specifically at a subset of sites. Accordingly, micropollutants were not represented by a few dominant variables but rather a diverse palette of different chemicals with similar contribution. As a group, micropollutants contributed similarly as metals, nutrient enrichment and morphological degradation. However, the importance of micropollutants might be underestimated due to limitations of the current chemical monitoring practices.
多重胁迫因素影响淡水系统，导致生态状况不佳，这符合欧洲水框架指令（WFD）的要求。为了选择有效的缓解措施并改善生态状况，需要了解胁迫层次结构以及单一和联合效应。然而，与营养物富化和形态退化等常见胁迫因素相比，农药和药品等微污染物的相对重要性在很大程度上尚未得到解决。我们使用德国萨克森州的 WFD 监测数据，调查了 108 个地点的 18 种底栖无脊椎动物指标的 85 种环境变量（包括 34 种微污染物）的重要性。这些环境变量被分配到五个组（自然因素、营养物富化、金属、微污染物和形态退化），并使用主成分分析（PCA）和提升回归树（BRT）根据它们在组内和跨组内的相对重要性进行分组和单独排名。总体而言，自然因素对模型总解释方差的贡献最大。该变量组不仅代表了采样点之间的类型差异，还代表了强烈受人为影响的变量（如电导率和溶解氧）的人类影响梯度。这些大规模的影响可能会掩盖其他变量组的个体重要性，这些变量组可能在一部分地点更为具体地发挥作用。因此，微污染物不是由几个主导变量代表，而是由具有相似贡献的不同化学品的多样化组合代表。作为一个组，微污染物的贡献与金属、营养物富化和形态退化相似。然而，由于当前化学监测实践的限制，微污染物的重要性可能被低估。
