Areal contraction, upward shift and habitat fragmentation in the cold-adapted ground beetle Nebria germarii Heer, 1837 in the Brenta Dolomites, Italy

Abstract

Changes in the spatial distribution of cold-adapted species appear to be influenced by macro- and microclimatic parameters. A growing body of evidence shows that alpine taxa are highly sensitive to climate changes. Global warming drives many cold-adapted species northwards and upwards, as conditions in their current habitats become more favorable for thermophilic and xerophilic taxa. We investigated changes in the spatio-temporal distribution of the cold-adapted beetle, Nebria germarii Heer, 1837 (Coleoptera: Carabidae), in the Brenta Dolomites (Italian Alps) by comparing historical data from collections with data from recent surveys. Our purpose was to verify whether this species has experienced an altitudinal shift of its lower distributional limit, and hence a shrinking of its spatial distribution, as other authors have suggested for other massifs of the Dolomites. Over 90 years, the lower range limit of this species has shifted ca. 350 m upward, its areal distribution has been halved and fragmented, and it is now extinct in the high alpine grasslands because of climate driven changes. The upward shift seemed to have accelerated in the last decades, suggesting even more attention is required on the topic. Similar changes are, according to recent literature, documented in many other taxa, and might lead to local or global extinction of specialist taxa, especially endemics in mountain areas. Intensified research on this topic is essential to monitor, understand, and hopefully mitigate, the loss of biodiversity in the Alpine ecosystems. We encourage others to use our findings as a starting point for further research on the model species, Nebria germarii, and similar taxa.