Effects of individual differences on higher-level processes
Broadly, I am interested in understanding how individual variation, especially in physiological state (e.g., energy, age, egg load, etc.), affects population- and community-level processes. I consider how individuals make behavioural decisions (mechanisms) as well as their outcomes.
I use a combination of theoretical and experimental approaches, encompassing field and lab work together with mathematical modeling and analysis.
Habitat selection decisions of individuals and effects on population-level processes
Under the supervision of Bernie Roitberg (Simon Fraser University) and Chao Li (Canadian Forest Service) my doctoral thesis considers how both energy and time constraints affect habitat selection decisions of individuals. I specifically consider how these constraints modulate habitat (i.e., host) selection in mountain pine beetle (MPB) and the resulting attack distributions of MPB in pine forests.
Successful mating and reproduction in this bark beetle species is contingent on successful search and colonization of host trees, which involves coordinated ‘mass attack’ required to overwhelm the host tree’s defences. Thus, an individual’s host selection decision policy must incorporate assessments of habitat resource quality, host defensive capability, and expected conspecific attack densities. Timing of attack and individual energy (lipid) reserves are further expected to modulate individual decisions.
Theoretical implementation of bark beetle genetic control
Selfish genetic elements have the potential to drastically reduce the fitness of a pest population via meoitic drive. I evaluate the theoretical potential for such a mechanism to maintain beetle populations below outbreak levels by coupling classic analytical population dynamics and population genetics models incorporating this genetic control element, within a spatially explicit simulation model of beetle infestation across a forest landscape.
Temperature-Dependent Community Dynamics
Working with Bernie Roitberg (SFU), Erin Udal (SFU), and Franz Simon (SFU), we are developing a temperature-dependent tritrophic community model of a plant, herbivore, and predator system. We are examining the effects of temperature changes and refugia on the dynamics and stability of such systems. We are following up with experiments to test the outcomes of the models.
Evolution of Omnivory in a Community Context
We developed an evolutionary simulation model to consider the feeding strategies (broadly classified as three feeding types: herbivores, omnivores, and carnivores) of a community of individuals and explore how the intrinsic properties of these foragers and extrinsic characteristics of their environment determine the prevalence of omnivores and other feeding types.