Predicting taxonomic, functional and phylogenetic diversity of plant assemblages in the Okanagan ecoregion

Taxonomic diversity, or species richness, has traditionally been the focus of biodiversity conservation efforts, but attention is increasingly being paid to measures of functional and phylogenetic diversity, which consider the range of ecological functions and unique evolutionary histories of assemblages. Despite the important benefits to using this multi-dimensional approach, especially in the context of rapid climate and land use change, regional-scale conservation initiatives continue to consider taxonomic diversity alone within their strategies. My general objective is to inform biodiversity conservation efforts in the Okanagan Ecoregion by quantifying and documenting, for the first time, current and future geographic patterns of taxonomic, functional, and phylogenetic diversity among the region’s vascular plant assemblages. My specific objectives are to: 1) Use species distribution models to predict current and future distributions of plant species inhabiting the Okanagan Ecoregion; 2) Quantify, map and compare current taxonomic, functional, and phylogenetic diversity patterns and hotspots in the Okanagan Ecoregion and compare to the current protected area network; and 3) Use climate projections to assess how future patterns and hotspots of taxonomic, functional, and phylogenetic diversity may differ from current. Using a reproducible protocol, I produced current and future species distribution models for 1,541 plant species. I then used three plant traits that represent the ecological variation of plant life history strategies as well as a recently published phylogeny to quantify and map patterns of functional and phylogenetic diversity for plant assemblages in the Okanagan Ecoregion. Overall, I found that there was significant geographic variation between patterns of taxonomic, functional, and phylogenetic diversity. While current functional and phylogenetic diversity hotspots had the greatest amount of congruence, hotspots of species richness and functional diversity had essentially no congruence. With future climate projections, all hotspots showed significant decreases in congruence. Elevation became more positively correlated with all three diversity measures in the future, indicating that plant diversity may be shifting to higher elevation areas in response to climate change. The novel findings I provide here concerning patterns of functional and phylogenetic diversity should complement the taxonomic diversity patterns that inform conservation efforts in the Okanagan Ecoregion.Arts and Sciences, Irving K. Barber School of (Okanagan)Biology, Department of (Okanagan)Graduat