Integrating Phylogenetic Diversity, Complementarity, and Endemism for Conservation Assessment

Posadas et al.’s (2001) analysis of conservation priority setting for southern South America highlights the fact that “conservation of biodiversity requires knowledge of its history.” In addressing this need, they argue that conservation of “evolutionary potential and phylogenetically rare taxa” requires integration of “phylogenetic” diversity with other factors, including complementarity and endemism. Posadas et al.’s proposed strategy for priority setting appears to achieve that integration, based on nominated definitions of phylogenetic diversity, complementarity, and endemism. But these terms currently have a variety of interpretations in conservation biology, and there is a danger that a mix-and-match integration may produce an unworkable framework. We argue that Posadas et al.’s approach suffers from this difficulty and that, far from providing the claimed “better use of available information,” any application of their proposed methods could be detrimental to biodiversity conservation. We contrast their approach with phylogenetic diversity (PD; Faith 1992a), an existing, simple integration of phylogeny, complementarity and endemism. Given that PD based complementarity and endemism have had little application, we also illustrate their use in a biodiversity study of Coleoptera in New South Wales, Australia.