Maximising phylogenetic diversity in the selection of networks of conservation areas

Phylogenetic diversity (PD) is a biodiversity measure that takes account of phylogenetic relationships (hence evolutionary history) between taxa. It may therefore provide a better currency for conservation evaluation than taxonomic richness. Here, we demonstrate that, contrary to recent assertions, optimisation tools can be used to maximise PD in the context of complementary reserve selection, and that the spatial overlap between sets of sites maximising genus diversity and PD cannot be used as evidence that the first measure is a good surrogate for the second. Nevertheless, in our own analyses using data on bird genera in northwest South Africa we found that near equally effective results are obtained in the selection of complementary sets of sites when maximising for each of these two measures of biodiversity.