The phytoplankton functional group (FG) classification system sensu Reynolds enables evaluating the ecological status of rivers using the Q_(r) compositional index. Here, we apply the Q_(r) index to analyze the ecological conditions of the Southern Bug River, at the entire river length, in the early 20th century, testing it first on historic river phytoplankton data. Moreover, we combined the FG approach with the saprobic index and taxonomic richness to assess the ecological status of the river more reliably. The Bray–Curtis Similarity index highlighted the spatial clustering of river sites that corresponded well to the bioregions of the Eastern Lowlands and the Pontian Province. The Q_(r) index revealed a higher variation in ecological status among sites than the saprobic index. Therefore, we argue that the FG approach provides a sensitive ecological status indication approach for river phytoplankton, including historical human impacts. The method may improve understanding of reference conditions and assessing the ecological status of Ukrainian rivers, as requested by the European Water Framework Directive.

中文翻译：

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雷诺兹浮游植物功能分类方法有助于评估欧洲南部布格河（乌克兰）的历史生态状况

雷诺兹意义上的浮游植物功能群 (FG) 分类系统能够使用Q _{( r )}组成指数来评估河流的生态状况。在这里，我们应用Q _{( r )}指数来分析 20 世纪初南布格河全流域的生态状况，首先在历史河流浮游植物数据上进行测试。此外，我们将FG方法与腐生指数和分类丰富度相结合，以更可靠地评估河流的生态状况。布雷-柯蒂斯相似性指数强调了与东部低地和笨珍省的生物区非常对应的河流地点的空间聚集。Q ( _{r )}指数比腐生指数揭示了不同地点之间生态状况的更大差异_。因此，我们认为 FG 方法为河流浮游植物提供了一种敏感的生态状况指示方法，包括历史上的人类影响。该方法可以根据欧洲水框架指令的要求，增进对参考条件的理解并评估乌克兰河流的生态状况。