General research interests

My general interests are in ecology, evolution and conservation - especially of plants. I am particularly interested in patterns of biodiversity at multiple levels (species and genetic), and all of the processes that create these patterns, including human-induced landscape alterations. Two overarching goals drive my current research program:
(1) To advance an integrated understanding of how ecological and evolutionary processes interact to determine the structure and dynamics of populations and communities.
(2) To understand the historical and contemporary processes – especially anthropogenic disturbances and environmental change – that have shaped present-day patterns of biodiversity.

Ecology and evolution in plant communities

Following a period of several decades during which ecologists largely ignored genetic variation and evolution within species, the integration of evolutionary and ecological perspectives on the dynamics of populations and communities has flourished over the past 5-10 years. We have conducted theoretical and empirical research exploring a variety of related questions within this overarching theme, including the causes of positive relationships between species diversity and genetic diversity, and the influence of genetic diversity within species on invasion success and interspecific competition. Empirical work focuses on plants of open habitats, such as lawns, fields, and grasslands, which provide an ideal study system for experimental manipulations of genetic diversity. Recent experiments with dandelions (Taraxacum officinale) have revealed intriguing results on the consequences of genetic variation for invasion success in different environments. Building on previous studies, particular questions of interest at present include: (1) to what extent does environmental heterogeneity maintain genetic diversity in dandelion populations?; (2) does intraspecific genetic variation promote species coexistence?; (3) what are the relative roles of species turnover, phenotypic plasticity, and adaptive evolution in creating a match between environmental conditions and functional traits in plant communities?; (4) does species diversity constrain local adaptation within populations to abiotic environmental conditions? More broadly, a long-term goal of mine is to integrate into a single conceptual framework both ecological and evolutionary approaches to understanding the processes underlying patterns of biodiversity.

Human-mediated disturbance, environmental change, and biodiversity

Human habitat alteration and environmental change raise a wide range of issues concerning the ecology, genetics and conservation of populations and communities. Many decades or even centuries after intensive human land use has ceased in a given area, a legacy of past land use may persist due to the very slow colonization of plant species. In past research projects, I have investigated the long-term effects of former agricultural land use on forest-plant species diversity, community composition, genetic diversity, population performance, seed dispersal, and metapopulation dynamics in eastern North America and Europe. Recent and ongoing research in the lab focuses on the savannas and grasslands of Vancouver Island, and assessing the causes of vegetation change across space and time over the past ~150 years, since European settlement of the region. We have focused on interactions between native and exotic species, and the historical role of First Nations’ cultural practices, such as prescribed fire and plant trading, in shaping changes in plant populations and communities. Related projects in the lab are being conducted on a variety of landscapes and organisms, addressing key questions concerning the impacts of human disturbance and environmental change on biodiversity.