Eutrophication and brownification are ongoing environmental problems affecting aquatic ecosystems. Due to anthropogenic changes, increasing amounts of organic and inorganic compounds are entering aquatic systems from surrounding catchment areas, increasing both nutrients, total organic carbon (TOC), and water color with societal, as well as ecological consequences. Several studies have focused on the ability of wetlands to reduce nutrients, whereas data on their potential to reduce TOC and water color are scarce. Here we evaluate wetlands as a potential multifunctional tool for mitigating both eutrophication and brownification. Therefore, we performed a study for 18 months in nine wetlands allowing us to estimate the reduction in concentrations of total nitrogen (TN), total phosphorus (TP), TOC and water color. We show that wetland reduction efficiency with respect to these variables was generally higher during summer, but many of the wetlands were also efficient during winter. We also show that some, but not all, wetlands have the potential to reduce TOC, water color and nutrients simultaneously. However, the generalist wetlands that reduced all four parameters were less efficient in reducing each of them than the specialist wetlands that only reduced one or two parameters. In a broader context, generalist wetlands have the potential to function as multifunctional tools to mitigate both eutrophication and brownification of aquatic systems. However, further research is needed to assess the design of the generalist wetlands and to investigate the potential of using several specialist wetlands in the same catchment.

中文翻译：

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湿地作为减轻富营养化和褐化的潜在多功能工具

富营养化和褐化是影响水生生态系统的持续环境问题。由于人为变化，越来越多的有机和无机化合物从周围流域进入水生系统，导致营养物质、总有机碳 (TOC) 和水色增加，从而产生社会和生态后果。一些研究重点关注湿地减少养分的能力，但有关湿地减少 TOC 和水色度潜力的数据却很少。在这里，我们评估湿地作为减轻富营养化和褐化的潜在多功能工具。因此，我们在九个湿地进行了为期 18 个月的研究，从而估算出总氮 (TN)、总磷 (TP)、TOC 和水彩浓度的减少量。我们表明，这些变量的湿地减少效率在夏季通常较高，但许多湿地在冬季也很有效。我们还表明，一些（但不是全部）湿地有可能同时降低 TOC、水色和养分。然而，降低所有四个参数的通用湿地在降低每一个参数方面的效率低于仅降低一两个参数的专业湿地。在更广泛的背景下，综合湿地有潜力作为多功能工具来减轻水生系统的富营养化和褐化。然而，还需要进一步研究来评估综合湿地的设计，并调查在同一流域使用多个专业湿地的潜力。