Arctic ecosystem dynamics: assessing long-term ecosystem effects of natural and anthropogenic disturbance in the Canadian Arctic.

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My research team has used ecological field data (e.g., phenology, abiotic conditions, food availability) and biological samples to examine demographic consequences of natural and anthropogenic disturbance among free-living, Arctic-breeding predatory birds. Using the Arctic peregrine falcon (Falco peregrinus tundrius) as a study model, my lab has focused on conducting basic research that contributes to understanding how variation in environmental conditions and reproductive readiness combine to influence demography of a long-distance migrant. In an effort to understand community dynamics more completely, this proposal seeks funding to cost-share HQP-led research that incorporates interactions among producers and consumers into the study system. Conducted in collaboration with the Government of Nunavut, my research program is well positioned to establish a multi-decade program capable of investigating interactions among trophic levels in ways that can inform adaptation to environmental change and management of Arctic wildlife. We have established permanent sampling sites near the community of Rankin Inlet, Nunavut to investigate questions relevant to: 1) plant phenology and community composition; 2) trends in small mammal abundance; 3) avian abundance and distribution, and; 4) arthropod diversity and habitat associations. Data already exist for these components, and sampling sites are located within the study area where peregrine falcon breeding ecology has been studied since 1980. Consistent with previous study my long term objective is to test the working hypothesis that available food supply (i.e., resources) and weather, combined with reproductive readiness determine the demographic patterns observed among free-living, Arctic-breeding predatory birds. More specifically, my short term objectives are to test the following hypotheses: 1) that peregrine falcon reproductive investment is driven by the value of current offspring and current conditions, traded-off against forgoing current breeding in favor of self-investment and future breeding; 2) that visit rate by consumers (insect pollinators) is correlated with peak resource availability, and any corresponding shift in relative timing of this interaction is the result of phenological mismatch; 3) that post-dispersal seed predation by carabid beetles in the absence of vertebrate herbivores is compensatory, 4) that different plant species in close proximity to one another, and which that share pollinator species, compete for pollination, and; 5) that the distribution of inter-nodal links (i.e., food web) among four predator guilds exhibits high generalism (i.e., uniform). The work proposed here explicitly acknowledges the importance of biotic and abiotic interactions across tropic levels, emphasizes annual data collection over long time periods, and addresses questions and methods that have the potential to provide new insights into ecosystem dynamics.