Forest Management Effects on Structural and Functional Connectivity of Relict Abies pinsapo Forests in Southern Spain

This study examines the effects of silvicultural management on the functional connectivity of fragmented Abies pinsapo forests in southern Spain. Using biomass stock as a resistance proxy, connectivity was assessed through accumulated cost-distance and least-cost path analyses under three scenarios: low intervention, traditional silviculture, and intensive thinning aimed at reducing climate vulnerability. The intensive thinning scenario produced the greatest connectivity gains, reducing mean accumulated costs by approximately 18% and standard deviation by 15%, with local reductions reaching up to 60% between specific population pairs. Median costs also declined, indicating widespread improvements rather than isolated effects. Spatial analyses revealed that previously high-resistance zones, particularly in central and northern sectors, shifted toward more permeable conditions. Least-cost paths were shortened and alternative, more efficient corridors emerged, especially in areas subjected to silvicultural treatments. Connectivity benefits extended to peripheral populations, decreasing their relative isolation and contributing to a more balanced network structure. Targeted biomass reduction may reshape landscape resistance patterns and strengthened ecological linkages, highlighting adaptive silviculture as a potentially valuable strategy for improving landscape connectivity and supporting conservation planning.