Vulnerability to Climate Change of Forest Genetic Conservation Units Assessed Through Species Distribution Models

Conserving the genetic resources of major forest species is essential for mitigating climate risks associated with global change. Species distribution models and their projections under future emission scenarios are key tools for assessing climate-related threats to populations targeted for conservation efforts. In this study, we analyzed the populations included in the Spanish Network of Forest Genetic Conservation Units, comprising 297 units across twenty main forest tree species in Spain. We used species distribution models with high-resolution environmental data to assess habitat suitability across different climate scenarios and time periods. We introduced a Climatic Vulnerability Index to identify Genetic Conservation Units at risk of maladaptation by evaluating shifts in current conditions. Our results reveal spatial and interspecific heterogeneity in the future climatic vulnerability of the conservation network, as well as a relationship between expert-defined marginality and current climatic unsuitability under the Spanish Group model. Overall, our findings provide a basis for prioritizing conservation actions, guiding adaptive forest management, and supporting the long-term monitoring and viability of forest genetic resources under accelerating climate change.