Conservation biogeography of high-altitude longhorn beetles under climate change

High-altitude insects are expected to be strongly affected by climate change because of their limited range. Phytophagous species will be subject to further threats because of their dependence on host plants. We investigated the impact of climate change on the distribution of Italian high-altitude longhorn beetles (Cerambycidae) using a maximum entropy approach based on bioclimatic variables. We used 510 presence records for 15 species distributed throughout the Italian Alps and Apennines. Then, we combined climate-based predictions with vegetation data to predict the future changes in the extent of suitable areas. All species but two will move uphill to track suitable climates and will face a range contraction (with an average loss of 44%) under both climatic change scenarios considered. Suitable vegetation covers, on average, only 56% of the estimated current species ranges, which means that the future distribution will be even more limited. Given the importance of Italian mountains as hubs of diversity in the Mediterranean hotspot, these results are particularly alarming. Conservation actions that can mitigate the effects of climate change on high-altitude cerambycids should be focused on contrasting habitat loss and degradation through land preservation and the adoption of appropriate forest management practices