Biogeographic regionalization of Australia: assigning conservation priorities based on endemic freshwater crayfish phylogenetics

Abstract

There are many methods available for evaluating conservation priorities. Traditional methods of species richness, genus richness and critical species counts were compared with newer methods of phylogenetic and genetic diversity. Conservation priorities for areas designated by the Interim biogeographic regionalisation for Australia (Thackway & Cresswell, 1995) were assessed on the basis of the freshwater crayfish fauna of Australia. Distributions for all crayfish species were taken from the literature, and plotted in the IBRA areas. Species and genus richness, as well as the number of rare or endangered species were calculated for each area. A phylogeny of 35 representative crayfish based on 16 S rDNA sequence data was used to assess phylogenetic and genetic diversity of species and genera. Methods of species richness and phylogenetic diversity agreed to a large extent in their ranking of areas, both methods agreed that the north-west coast of Tasmania and the south-eastern portion of the continent were of highest priority for conserving the greatest amount of diversity. These results differ greatly from high priority areas based on other taxonomic groups, emphasizing the importance of broad taxonomic and ecological sampling in making conservation decisions.