Phylogenetic diversity and endemism of Australian daisies (Asteraceae)

Aim: To explore the performance of phylogenetic diversity metrics and of the novel categorical analysis of neo- and palaeo-endemism (CANAPE) using a dataset of Australian native Asteraceae and in particular to compare the results at two taxonomic ranks: genus and species. Location: Australia. Methods: We used specimen data from Australia's Virtual Herbarium to produce species and genus distribution models with Maxent, and reconstructed a genus-level phylogeny. Spatial analyses were conducted at a 100 km × 100 km scale. Randomization tests were employed to identify cells with significantly high or low values of phylogenetic diversity (PD), and CANAPE was used to identify significant hotspots of neo- and palaeo-endemism. Results: Significantly high PD values were found scattered along the northern and north-eastern coast, whereas significantly low PD values characterized the arid interior. CANAPE signalled hotspots of neo-endemism in the mountainous south-east of Australia and hotspots of palaeo-endemism in the tropical north. Patterns were similar between genus-and species-level analyses, although the latter inferred more cells with significant values. Main conclusions: PD and CANAPE generally provided results for Australian Asteraceae consistent with expectations based on previous studies. This is further evidence for their utility in formulating and testing hypotheses about phylogenetic and biogeographical processes. The strength of the results is, however, partly dependent on the taxonomic scale of the analysis, a fact that has to be taken into account in the design and interpretation of future studies.