The conservation, management and monitoring of aquatic resources should benefit from understanding their spatial structuring. In this paper, we used the reference condition approach (RCA) to test if the variability in biotic communities, riverine fish assemblages in the present case, is better controlled with a spatial delineation based on ecoregions or by grouping rivers with local catchment characteristics. Electrofishing data from 493 riffles in 99 rivers in Finland were used in the analysis. We completed multivariate analyses (nonmetric multidimensional scaling, multiresponse permutation procedures) to identify differences in fish community composition among groups based on ecoregions or catchment characteristics. We concluded that both regional processes and local environmental characteristics structured fish populations, and bioassessment of freshwaters should be based on regional spatial delineations, supported by local scale characteristics. Spatial delineations like ecoregions should be used to assist the bioassessment to improve the efficiency to detect the human impacts.

中文翻译：

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生态区和当地环境特征对北方河岸鱼类种群空间格局的影响

对水生资源的保护，管理和监测应从了解其空间结构中受益。在本文中，我们使用了参考条件方法（RCA）来测试是否可以通过基于生态区域的空间划分或通过将具有局部集水特征的河流分组来更好地控制生物群落（当前河流鱼类）的变异性。分析中使用了来自芬兰99条河流中493浅滩的电钓鱼数据。我们完成了多变量分析（非度量多维标度，多响应置换程序），以根据生态区域或流域特征来识别各组之间鱼类群落组成的差异。我们得出结论，区域过程和当地环境特征都构成了鱼类种群，淡水的生物评估应基于区域空间划分，并得到当地尺度特征的支持。应该使用诸如生态区域之类的空间划界来辅助生物评估，以提高发现人类影响的效率。