Evolutionarily significant units in a flightless ground beetle show different climate niches and high extinction risk due to climate change

Species distribution models (SDMs), especially those basing on climatic parameters, have frequently been used to project future species ranges and to develop conservation strategies. As suggested by several authors, we considered both different dispersal abilities and different evolutionarily significant units (ESUs, as determined in an earlier genetic survey). For our study species, the flightless ground beetle Carabus irregularis, SDMs for two ESUs from the western and the Carpathian area of the distribution range showed immense, and deviating future range contractions reflecting divergent ecological requirements. As minimal dispersal SDMs resulted in a stronger decline of future ranges than the maximal dispersal models, low dispersal ability tended to strengthen the already high vulnerability of the cold-adapted mountain species to global warming. Areas shown in our maximal dispersal models as offering climatically suitable habitats for C. irregularis in the future should be considered as potential areas of action in future conservation planning (e.g. assisted migration or assisted colonisation). Thus, both dispersal scenarios and different (if applicable) ESUs should be considered when developing SDMs as useful tools for species conservation strategies adapted to species’ performance and differentiation patterns.