Conserving genetic diversity hotspots under climate change: Are protected areas helpful?

The conservation of genetic diversity is a major target of the Kunming-Montreal Global Biodiversity Framework and of the EU Nature Restoration Law, as it provides populations with the potential to evolutionary adapt to the ongoing environmental challenges. However, genetic diversity has often been neglected in the conservation planning, and data on the extent to which it is currently preserved by protected areas are scanty. Here, we assessed the efficacy of protected areas in preserving genetic diversity hotspots under global change. Focusing on the Italian peninsula inside the Mediterranean global biodiversity hotspot, we (i) investigated the patterns of genetic diversity of endemic terrestrial vertebrates, (ii) assessed how much genetic diversity is currently covered by protected areas considering both nuclear and mitochondrial DNA, and (iii) estimated the impact of projected range shifts caused by climate changes on the conservation of genetic diversity patterns. We found that protected areas cover <20% of the areas of high genetic diversity for most of the investigated taxa, and fail to cover almost all multispecies genetic diversity hotspots. Furthermore, our results showed that mitochondrial DNA is not a reliable proxy for nuclear genome diversity, and its use in spatial conservation planning might lead to ineffective initiatives. Finally, we estimated that the extent of genetic diversity covered by protected areas will dramatically decline in the near future (2050). These results identify major gaps in current protection of genetic diversity and provide concrete guidelines to plan area-based conservation initiatives that meet biodiversity conservation targets for 2030.