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Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to analyse evolutionary patterns of range size, abundance, and species richness. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics, i.e. closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species, while mean range size and abundance are significantly, positively correlated. These correlations are stronger in the raw data, but still significant when using phylogenetically independent contrasts. We suggest that tree stature and/or other phylogenetically related biological traits underlie these results. Lineages comprised of small-statured trees show greater species richness and smaller range sizes and abundances. Lastly, the phylogenetic signal that we evidence for range size suggests that should many small ranged species go extinct, greater phylogenetic diversity may be lost than expected if range size were distributed randomly across the phylogeny.
This is a submission to PeerJ for review.
Genera used in this study and associated Genbank Accession Numbers
This .csv file contains a list of all Amazonian tree genera that are present in the phylogeny we constructed, as well as Genbank Accession numbers for the rbcL sequence and matK sequence where pertinent.
Fossil calibrations used to temporally date phylogeny
This .csv file lists the nodes for which ages were constrained as well as giving the minimum age, mean age and standard deviation for the log-normal prior distributions (with offset) used in BEAST analyses.
Taxonomic lineages present in paper with associated summary statistics
This .csv file lists each higher-than-genus-level lineage used in this study that has a Linnean taxonomic name. It then gives the age, number of constituent genera used in different analyses and reconstructed mean values for genus-level characteristics studied.