My work focuses on how rapid evolution may mediate community response to environmental change. Using mainly experimental systems, I study how ecological processes such as community assembly, stability, productivity and coexistence are altered when the populations also evolve over equivalent timescales.
I am currently a PhD candidate in the Bell lab at McGill University where I use duckweed (Lemnoideae) as a model to study eco-evolutionary dynamics. |
Experimental evolution in
phytoplanlton |
Experimental
eco-evolutionary dynamics in Floating aquatic plant communities |
Experimental community ecology in
Forests |
Community selection
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Does rapid evolution play an important role in shaping community response to environmental change?
In communities, average trait values may respond to environmental change by shifts in species relative abundances in addition to shifts within species via phenotypic plasticity. Furthermore, rapid evolution may alter traits within a population and interact with both species sorting and phenotypic plasticity. We designed a large-scale semi-natural mesocosm experiment to test the relative contributions of ecological, physiological and evolutionary processes to shaping communities of Lemnaceae. We founded identical communities containing millions of individuals which were then manipulated by establishing a crossed gradient in light and nutrients. We then measured community response in traits over ~25 generations in 18 mesocosms. |
An extensive reciprocal transplant experiment was then used to evaluate the processes responsible for overall community response. Species-relative abundances and the traits for ~4000 individuals were measured in communities assayed in both their original and modified environments. By measuring the degree to which populations return to their ancestral phenotypes we can partition physiological from genetic effects. This experiment then gives us a quantitative measure of the relative contributions of phenotypic plasticity, species sorting and rapid evolution in determining community responses to a changing environment.
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Local Adaptation in the field
Is Lemna minor adapted to local resource levels?
A comprehensive field survey of 40 sites in summer 2019 allows us to asses to what degree our mesocosm results apply to natural communities. By measuring species traits, species relative abundances and environmental parameters, we can determine how inter and intra-specific processes interact to determine community structure. By collecting ~120 strains of Lemna minor across natural environmental gradients and growing them in a controlled common garden in the lab, we can test for a genetic basis of variation in key traits and asses the relative roles of the same three fundamental processes (physiological, ecological and evolutionary,) in shaping natural communities. |
Biodiversity-Ecosystem function
If tree diversity accelerates rates of primary productivity, does litter decomposition also increase proportionally to balance the carbon budget?
This works uses an experimental tree plantation where species and functional diversity were independently manipulated to asses to effect of tree diversity on rates of leaf-litter decomposition, soil respiration and nutrient cycling. Link to publication Link to publication |
Adaptation to high CO2
The concentration of CO2 in the atmosphere is expected to double by the end of the century. Experiments have shown that this will have important effects on the physiology and ecology of photosynthetic organisms, but it is still unclear if elevated CO2 will elicit an evolutionary response in primary producers that causes changes in physiological and ecological attributes. In this study, we cultured lines of seven species of freshwater phytoplankton from three major groups at current (approx. 380 ppm CO2) and predicted future conditions (1000 ppm CO2) for over 750 generations.
Link to publication |
photo: Etienne Low-Décarie
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