Role of palaeogeographical and ecological factors on the evolution and assembly of plant communities

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I integrate the fields of biogeography, phylogenetics, geology, and ecology to understand the origin and assembly of biota on island systems. This work can help mitigate biodiversity loss. My long-term research program aims to explain how historical events and current ecological factors have influenced the evolution and distribution of plant species in tropical and boreal regions. Using case studies and synthesizing publicly available information my research group has three inter-related short-term objectives: 1) elucidate the historical biogeography of Caribbean plants; 2) study the formation of seasonally dry forests (SDTF) in the Andes; and 3) infer the potential assembly processes of plant communities on a boreal island. The Caribbean is important to study and conserve because it is one of the world's top five biodiversity hotspots. We will investigate the role of three hypotheses: colonization, insular speciation, and vicariance on the origin of Caribbean flora. Using published dated phylogenetic trees, we will infer ancestral areas of plants to test predictions of the effects of Caribbean geological history on the colonization or vicariance of plants. We will also estimate colonization and speciation rates from these phylogenies. DNA sequencing will be used to reconstruct the phylogenetic tree and biogeographic history of Copernicia, a Caribbean radiation of 21 palm species, as a case study. Up to a third of the global population live in dry tropical areas, which are some of the most endangered ecosystems in the tropics. Objective 2 will provide a spatial and temporal framework for SDTF formation, which will complement the incomplete geological evidence of Andean formation. Using DNA sequencing, we will conduct a phylogeographic and historical demographic analysis of two SDTF species in the cactus family at six localities in the Colombian Andes. The field of phylogenetic community ecology was born with the suggestion that the phylogenetic distances separating species in a community, could indicate whether abiotic, biotic or random factors drive the community assembly. We will test two conditions needed to make these inferences on a boreal island. Using six habitats in Newfoundland we will first evaluate if the phylogenetic distances of species are narrow or wide on a lineage-by-lineage basis. Second, we will test if trait adaptations to these habitats are evolutionary conserved or not. My research program will contribute to the field of island biogeography using a historical and current ecological perspective in the tropics and boreal. It will complement geological evidence aimed at reconstructing the onset, duration and spatial context of the Caribbean archipelago and the Andean uplift. My long-term research will impact the conservation of tropical and boreal ecosystems by informing the design of protected areas and the restoration of heavily disturbed areas. Three PhDs, two MSc, and five undergraduate students will be trained.