Projected climate-driven contraction of Mediterranean coniferous and mixed forests in North Africa: Ensemble SDMs with dispersal constraints

Effective management of Mediterranean forests requires a clear understanding of their vulnerability and adaptive capacity to climate change. This study aimed to quantify climate-driven range shifts of native tree species in North Africa and to assess how species-specific dispersal limitations constrain access to future suitable habitats. We examined the impacts of climate change on 23 native tree species representing six plant families in the Mediterranean coniferous and mixed forests (MCMF) of North Africa. Using over 377,000 tree occurrence records and applying a species distribution model (SDM) framework, we combined climate, topography, and soil variables into an ensemble model to project range shifts under the SSP2-4.5 and SSP5-8.5 scenarios by 2050. In addition, we developed a novel approach to integrate species dispersal capacity with future habitat projections. The models showed generally high predictive performance, with mean AUC values around 0.9 and mean TSS values around 0.6 across species. Almost all species, especially Abies pinsapo, Cedrus atlantica, and several species of the Acer and Juniperus genera, were projected to experience substantial reduction in suitable habitats. Incorporating dispersal constraints reduced predicted habitat gains by approximately 3.7-3.9%, indicating that a considerable portion of newly suitable climate space may be inaccessible to many species by mid-century. The mean range loss was more pronounced in North Africa than across the wider Mediterranean basin. These findings suggest that dispersal limitations, combined with intensifying climate pressures, are likely to accelerate the shrinkage of remaining temperate forests in North Africa, underscoring the urgent need for proactive and adaptive forest management strategies.