Thermal Stress and Habitat Loss: Assessing the Vulnerability of Potamon fluviatile (Decapoda: Potamidae) to Climate Change in Italy

ABSTRACT Climate change has the potential to alter the distribution of freshwater species and challenge the effectiveness of existing conservation networks. However, projections of the climatic suitability of Potamon fluviatile under recent climate scenarios are lacking for Italy. In this study, we modeled the potential climatic distribution of the species using an ensemble species distribution modeling approach based on multiple future climate projections. Results indicate that temperature conditions during the dry season are an important predictor of the species' large‐scale climatic suitability. Future projections show a contraction of suitable areas, with moderate declines under low‐emission scenarios (SSP1‐2.6) and substantial reductions exceeding 80% by 2070 under high‐emission scenarios (SSP5‐8.5). The models show limited expansion into newly suitable areas, although dispersal processes were not represented. Comparing projected suitability with the current protected area network shows that existing conservation boundaries may not cover future suitable areas. While some large protected areas may experience declines in suitability, some smaller coastal reserves may retain stable climatic conditions. It is important to consider that our findings are based on coarse‐scale climatic predictors and do not account for hydrological processes or fine‐scale habitat characteristics. Our study provides a large‐scale assessment of potential climate‐driven changes in climatic suitability for P. fluviatile in Italy. Integrating climatic, hydrological, and ecological processes in future models would improve conservation planning for freshwater species.