University of Applied Sciences Trier, Environmental Campus Birkenfeld, P.O. Box 1380, 55761 Birkenfeld, Germany; University of Duisburg-Essen, Faculty of Biology, Universitätsstrasse 5, 45141 Essen, Germany.
Netherlands Institute of Ecology, Department of Aquatic Ecology, Droevendaalsesteeg 10, 6708 PB Wageningen, the Netherlands.
Sci Total Environ. 2019 May 1;663:486-495. doi: 10.1016/j.scitotenv.2019.01.330. Epub 2019 Jan 26.
Assessments of river restoration outcomes are mostly based on taxonomic identities of species, which may not be optimal because a direct relationship to river functions remains obscure and results are hardly comparable across biogeographic borders. The use of ecological species trait information instead of taxonomic units may help to overcome these challenges. Abundance data for fish communities were gathered from 134 river restoration projects conducted in Switzerland, Germany and Finland, monitored for up to 15 years. These data were related to a dataset of 22 categories of ecological traits describing fish life-history strategies to assess the outcome of the restoration projects. Restoration increased trait functional diversity and evenness in projects that were situated in the potamal zone of rivers. Restoration effect increased with the length of the restored river reaches. In areas with low levels of anthropogenic land use, the peak of the restoration effect was reached already within one to five years after the restoration and effect receded thereafter, while communities responded later in areas with higher levels of anthropogenic land use. In the lower potamal zone, a shift towards opportunistic life-history strategists was observed. In the upper rhithral zone, in contrast, species with an opportunistic life-history strategy increased only in the first five years of restoration, followed by a shift towards equilibrium strategists at restorations older than 5 years. This pattern was more pronounced in rivers with higher level of anthropogenic land use and longer restored river reaches. Restoration reduced the variability in community trait composition between river reaches suggesting that community trait composition within these zones converges when rivers are restored. This study showed how ecological traits are suitable to analyse restoration outcomes and how such an approach can be used for the evaluation and comparison of environmental management actions across geographical regions.
河流修复效果的评估大多基于物种的分类学身份，这可能并不理想，因为与河流功能之间的直接关系仍然不清楚，而且结果在生物地理边界上几乎无法比较。使用生态物种特征信息而不是分类单元可能有助于克服这些挑战。从瑞士、德国和芬兰进行的 134 个河流修复项目中收集了鱼类群落的丰度数据，这些项目的监测时间长达 15 年。这些数据与描述鱼类生活史策略的 22 个生态特征类别的数据集相关联，以评估修复项目的结果。在位于河流波塔马拉区的项目中，修复增加了特征功能多样性和均匀度。修复效果随着修复河流长度的增加而增加。在人类土地利用水平较低的地区，修复效果在修复后 1 至 5 年内达到峰值，此后效果减弱，而在人类土地利用水平较高的地区，群落的反应较晚。在下部波塔马拉区，观察到向机会主义生活史策略的转变。相比之下，在上部里塔尔区，只有在修复的头五年，具有机会主义生活史策略的物种才会增加，而在修复超过 5 年的河流中，才会转向平衡策略。这种模式在人类土地利用水平较高和修复河流长度较长的河流中更为明显。修复减少了河流之间群落特征组成的变异性，这表明当河流得到修复时，这些区域内的群落特征组成趋于收敛。本研究展示了生态特征如何适合分析修复效果，以及这种方法如何用于评估和比较跨地理区域的环境管理行动。
