Effect of non-native species on taxonomic and functional diversity of fish communities in different river types

Abstract Recent researches suggest that functional diversity represents the response of communities to environmental alterations better than taxonomic diversity. However, there is scarce information about how freshwater fishes affected by habitat type and dominance non-native species. To address this question, we analysed a large database containing 15 morpho-functional traits 61 fish species from Pannon Biogeographic region (Hungary). Based on faunistic list relative abundance taxa, quantified riverine for > 700 sites six types. We asked in different river types at local scale (i.e. site level), measures native fauna elements changes along invasion gradient. Our results showed both richness increases with complexity, small headwater streams rivers. Therefore served as good proxy gradient Non-natives considerable their number each type. Diversity values initially increased, then major decrease River type-specific evaluations highlighted importance considering proliferation invasive based indices. argue action plans are needed conservation management preserve Hungary, but also elsewhere.