Climate change reduces range overlap among congeneric plant species in the Iberian Peninsula and Balearic Islands

Climate is a major driver of species distributions, yet climate change is reshaping these patterns worldwide, particularly in biodiversity hotspots such as the Iberian Peninsula and Balearic Islands. Here, we evaluate how climate change may alter the range overlap of 20 congeneric plant species pairs using ensemble species distribution models (SDMs). Models were calibrated under current climate and projected to 2070 using two global circulation models and two emission scenarios. Our results reveal a generalized decline in overlap areas under future climates, especially in high-emission scenarios, with some species pairs losing overlap entirely due to predicted local extinctions. A minority of pairs, mostly involving thermophilic taxa, exhibited increased overlap linked to range expansions. Overall, our findings indicate that climate-induced alterations in range overlap could potentially affect species in the Mediterranean region. Incorporating projections of overlap dynamics into conservation planning is therefore crucial for anticipating risks to interspecific interactions under accelerating climate change.