Invertebrate diversity and national responsibility for species conservation across Europe – A multi-taxon approach

Invertebrates play important roles in ecosystem functioning, but with the decline in biodiversity worldwide, it has become increasingly evident that our knowledge of invertebrate diversity distributions and of how to adequately integrate many invertebrates into conservation strategies is insufficient. We analyzed congruence between patterns of total as well as of endemic species richness of twelve invertebrate taxa across Europe and compared these patterns to those of so far predominantly studied vertebrates and plants. Coarse-scale centers of high collective diversity were identified, all in southern European regions. However, the strength of covariation between diversity patterns strongly depended on the respective taxa, with ground beetles emerging as one of the invertebrate taxa significantly reflecting endemism and total species richness distributions of many invertebrates, vertebrates and plants. Plants and ants showed similarly strong cross-taxon correlations. In contrast, correlations of vertebrates with invertebrates were in part less strong, questioning whether conservation strategies based on the former adequately account for diversity of invertebrates as a whole. Moreover, as the potential impact of environmental factors on diversity distributions varies among taxa, future climate change might affect relationships between richness patterns of different taxa. Our findings draw attention to the necessity of incorporating invertebrates, represented for instance by the highly diverse ground beetles, into national and international conservation decisions. They also highlight the importance of individual countries in maintaining European biodiversity and the responsibility of these countries for specific invertebrate taxa within international conservation frameworks, emphasizing the need for adequate consideration of invertebrates in the implementation of conservation actions.