Research in population ecology

Current research and vision

Population ecology is currently the primary focus of my work, with two projects focusing on plants and bees, respectively. While coming from different angles, these projects address a similar problem: while there is a general expectation that climate change will be bad, reality is complex; we often don’t know (a) how effects of climate change integrate across organisms’ whole life cycles, or (b) the importance of these effects relative to each other or other environmental forces. These limitations make clear predicitons difficult. To address these gaps, my current work uses field-based experiments to determine the demographic consequences of climate change.

Long term, I aim to have a research program that continues to include both plants and bees. These taxa are intimately interconnected, and I am interested in how populations of each respond to each other and their shared environment.

Population consequences of phenological shifts

I am working with Dr. Amy Iler to investigate the effects of phenological shifts (driven by climate change) on plant population growth. While the effects of climate change have been studied before, they are often studied in isolation—that is, on individual vital rates. By following cohorts of plants through time, we will integrate the environmental effects across the whole life cycle while accounting for trade-offs between vital rates. In doing so, we will be able to better understand whether, how, and why plant populations might respond to changing environments.

Effects of the biotic and abiotic environments on population viability

Together with Dr. Paul CaraDonna, I am co-PI on a recently funded NSF grant to study the effects climate change on solitary bees. Climate change can (potentially) affect bee populations in many ways, including direct effects of the abiotic environment (e.g., temperature), and indirect effects mediated by the biotic environment (i.e., food availability, predation rates). In this project, we will use an experimental demography approach to assess the role of multiple biotic and abiotic factors affecting population dynamics of a solitary bee (Osmia ribifloris), how their responses are shaped by plasticity versus adaptation, and how these environmental factors come together to affect population viability under different climate scenarios.

Past projects

In my PhD work on wild bee populations, I used population genetics as a tool to better understand bumble bee populations. In one study, I used rates of genetic isolation-by-distance to jointly estimate effective population densities and dispersal distances of six bumble bee species. In another, I more closely examined the population genetics of Bombus impatiens, assessing colony densities and genetic diversity, and meausuring the effect of different habitats on rates of gene flow between subpopulations of Bombus impatiens (“isolation-by-resistance,” sensu McRae 2006).