Priority areas for phylogenetic diversity: Maximising gains in the mediterranean basin

Abstract

Phylogenetic diversity (PD) is a valuable component of biodiversity, reflecting variation produced by past evolutionary processes and providing options for future generations. A challenge is to design and implement effective conservation actions for the preservation of PD for multiple taxonomic groups. We here proposed a region-level approach to this aim because some previous research at this scale may have been misleading. We focused on a biodiversity hotspot, the Mediterranean Basin, as a case study. We assessed how much PD does not yet receive any protection for three vertebrate groups: amphibians, squamates and terrestrial mammals. We found that a very low proportion of the PD of the region was protected, justifying the urgent need to set up conservation actions to safeguard PD. We identified sites whose protection would maximise the persistence of the PD of the Mediterranean region. Our methodology focused on two criteria for selecting sites that were prioritised for protection: the gain in PD representation and the gain in securing threatened PD. Our results show that potential protected areas were widely distributed across the basin and were generally different across the three taxonomic groups. However, several common priority sites were concentrated in islands the Maghreb and Spain and in the Eastern part of the basin. Our study attempts to further develop an effective framework for priority settings based on PD. We also discuss a risk approach where conservation decisions depart from the idealised case of a minimum set of areas that would protect the whole PD of the region.