Structuring Mechanisms of Ecological Communities

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Abiotic (eg, climate, physical environment) and biotic (eg, predation, competition) processes, along with random chance (eg, severe storms, fire) are known to interact and their effects to be mediated through spatial processes, ultimately determining the distribution of individual species and their aggregated products, ecological communities. Studies have shown respective factors can vary in their relative importance in determining community composition. Also, it has been shown that such studies may be influenced by choice of measure considered to characterize the community (eg, taxonomic composition, body size, functional traits such as whether they are predators or require warm temperatures), the spatial and temporal scale considered, and the type of species studied (eg, plants, birds). The proposed research will study relationships in biodiversity (measured on species taxonomy, species morphology, evolutionary relatedness of species, and species functional traits) of fishes in nearly 10,000 Ontario lakes and test whether these different measures respond similarly to environmental conditions. Using data from >1000 lakes that have been sampled multiple times, I will answer fundamental questions posed by Charles Darwin about invasive species and community composition to assess the types of species most likely to be successful invaders and what impact they have on the recipient community. I will compare lake fish communities from Ontario and European lakes to determine whether environmental conditions have selected for similar ecological outcomes (convergence) on the morphology and functional traits of communities, despite the species being largely unrelated through evolution. I will use simulations of lake temperature and fish growth, along with field sampling to test whether we can predict the types of lakes that are more likely to serve as colonization points for Smallmouth Bass along its northern distribution range, as it is a species expanding its range and known to have important effects within lakes where it colonizes. Ecologists and evolutionary biologists often have multiple sets of data, based on similar measurements (e.g. morphology of different fish species) that must be compared to one another. We know that these comparisons are very sensitive to unusual observations (e.g. a deformation on one part of one fish), yet we do not currently have methods well suited to minimize the effect of such unusual observations. I will develop and assess methods that will provide powerful statistical methods suitable to analyse observations having such challenging conditions, and develop a statistical package available to researchers in ecology and evolutionary biology, as these types of problems are common across our fields.