An updated megaphylogeny of plants, a tool for generating plant phylogenies and an analysis of phylogenetic community structure

The aim of this article is 3-fold. First, we present an updated version of a published megaphylogeny of vascular plants that can be used in studies of plant ecology and biogeography. Second, we develop a tool that can be used by botanists and plant ecologists to generate phylogenetic hypotheses in three scenarios. Third, we use a set of regional assemblages of angiosperm trees in North America as a model system to evaluate the effect of differences in phylogenies generated using the three scenarios on the quantification of phylogenetic properties and the relationship between measures of phylogenetic properties and environment. The taxonomy and nomenclature of plant species in the megaphylogeny were standardized according to The Plant List (version 1.1). A tool for generating phylogenies was created using the R language. The robustness of derived phylogenies was evaluated using correlation and regression analyses. An updated megaphylogeny of vascular plants (PhytoPhylo) and a tool for reconstructing phylogenies of seed plants (S.PhyloMaker) were generated. Our study shows that phylogenies generated by S.PhyloMaker using the PhytoPhylo megaphylogeny as a backbone are nearly as good as phylogeny resolved at the species level when using derived phylogenies to quantify phylogenetic properties (e.g. phylogenetic diversity and phylogenetic relatedness) of biological assemblages, and that S.PhyloMaker-generated phylogenies are robust for studies of community ecology and biogeography, particularly those seeking for patterns of phylogenetic properties along environmental gradients.