Research Data related to: Multispecies climate refugia and suitability persistence to guide strategic protected area expansion under climate change

Aim Mountain ecosystems are highly vulnerable to climate change despite hosting a disproportionate portion of global biodiversity. The Apennines are a key biodiversity hotspot, yet their potential climatic refugia remain poorly understood. We aimed to develop a metric to identify potential climatic refugia for multiple species, and to quantify areas of multispecies suitability persistence under future climate scenarios to prioritize protected areas’ (PAs) expansion.Location Apennines range, Italian Peninsula.Taxon Ten vertebrate species representing multiple taxonomic groups associated with high-elevation habitats.Methods We modelled species distributions using species distribution models (SDMs) implemented with the maxnet algorithm, testing different parametrization techniques and spatial block cross-validation. We defined suitability persistence as areas remaining suitable across time and species. Binary projections were combined into a persistence layer, followed by a gap analysis at three persistence thresholds. To investigate environmental correlates of persistence, we fitted generalized additive models (GAMs) relating persistence to climatic, topographic, and anthropogenic variables.Results Most species are projected to contract, with expansion observed only for three species (alpine snowfinch, piedmont ringlet and eros blue). Multispecies climatic refugia (MCR) were primarily concentrated in the Northern and Central Apennines, with marked declines in persistence projected for Central and Northern sectors (~0.16 and ~0.18, respectively). Protection coverage of MCR spanned from 36.8% to 58.2%, highlighting gaps, particularly in the Northern Apennines. Areas of high suitability persistence were associated with higher elevations, lower human pressure, increased precipitation during the warmest quarter, cooler summer temperatures, and mean annual temperatures between 5°C and 7°C.Main conclusions Our findings provide spatially explicit priorities for expanding PAs and informing climate-adaptive conservation strategies. By operationalizing suitability persistence within a multispecies framework, we identify robust refugial areas under climate uncertainty. Integrating these results with connectivity planning and long-term monitoring could enhance the resilience of mountain biodiversity to ongoing climate change.