Eco-evolutionary dynamics of population spread and plant demography in a changing world

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Two major threats to biodiversity are climate change and land use changes. In western North America, not only will temperatures likely increase by 2 - 4 ºC in the next century, but precipitation patterns will shift. Understanding how such changes drive the dynamics of individual populations, that is the extent to which they are increasing or decreasing through time, is critical for conserving threatened species and managing invasive ones. Scientists now recognize that evolution on contemporary time scales can influence not only traits of individuals, but also population dynamics. A current challenge in ecology is thus to integrate the role of evolution in population dynamics with the major environmental changes the world currently faces. To tackle this challenge, I seek to understand how environmental changes influence the ecological and evolutionary processes that influence where species occur, how abundant they are and how the abundance of individual populations changes through time. Over the next 5 years, my research program will integrate development of theoretical models with field and greenhouse experiments in two complementary areas. First, recent studies show that evolution can be the driving mechanism behind the range expansion of plants and animals, and that scientists may be underestimating how quickly species can shift their ranges. However, despite recent advances, making predictions about the speed of range expansions is inherently difficult. My research will include an ambitious set of experiments to evaluate new theoretical predictions for the factors that influence how evolution influences the predictability of expansion speed. The results will play an important role in the advancement of this field and contribute to more effective conservation and management strategies. Second, predicting how climate change influences which species are most vulnerable due to their evolutionary responses is key to disentangling the factors that drive changes in biodiversity, and to decision making to manage risks and reduce or avoid costs associated with climate change. I will examine how variability in climate affects the timing of when plants flower and how much energy they allocate to making flowers and seeds, capitalizing on a field experiment I established in the endangered Garry oak ecosystem that manipulates rainfall. We will make predictions for how changes to both mean and variability in rainfall will influence optimal reproductive strategies and the ability of populations to persist. Our results will evaluate long-standing theory and highlight characteristics of species that make them more vulnerable to climate change, allowing us to articulate how changes to individual species will drive changes in biodiversity now and in the future.