Local abundance, geographic range size, and habitat breadth of species have distinct effects on extinction risk. Documenting how these three axes of rarity are distributed across phylogenies provides insights into whether extinction risk is phylogenetically conserved and the potential for species-level selection. The aim of this study was to test for phylogenetic signal in abundance, geographic range size and habitat breadth among the regional pool of 1,700+ woody plant species at the Madidi Region of the Bolivian Andes. We used a network of 48 1-ha forest plots and 442 0.1-ha forest plots to measure local abundance and habitat breadth of 1,700+ species (from 100+ plant families), and occurrence records of individual species across the Neotropics to measure geographic range size. We characterized phylogenetic patterns of rarity with variance partitioning analyses among different phylogenetic depths.
Most variance in local abundance, geographic range size and habitat breadth was due to differences among species within genera. However, we found significant phylogenetic signal in these three axes of rarity, particularly at the family and genus level: confamilial genera and congeneric species were more similar than expected by a null model that assigned species at random across the species pool phylogeny. These results suggest phylogenetic signal in extinction risk and concomitant potential for species-level selection on attributes that influence population distribution and abundance.