Marilyne Robidoux
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514-987-3000, ext 4667
Université du Québec à Montréal
Pavillon des sciences biologiques, SB-2355
2080 St-Urbain
Montréal, Québec
H2X 3X8
Canada
MSc
BSc
My work will focus on selective trade-offs along dissolved organic carbon (DOC) lake gradients to estimate the importance of intra-specific trait variation (ITV) in crustacean zooplankton communities. As a first objective, I will test how body size and fecundity will change under trade-offs imposed by different stressors related to expected climate change impacts on food webs. Both bottom-up effects associated with food resources and top-down predation can simultaneously mediate selection on traits such as body size and fecundity in crustacean zooplankton. However, there are contrasting expectations for effects of climate-induced DOC changes on these traits in crustacean zooplankton. These trade-offs are important because body size is often related to fecundity, and distribution shifts in these population traits could have community and ecosystem-level consequences. Secondly, I will link patterns of phenotypic trait variation across spatial scales and among levels of biological organization (among or within species). Since a species is a collection of individuals with a variety of traits and it is at the level of individuals that ecological interactions occur, it is important to consider trait variation within species. I predict that trait variation in body size and fecundity will be greater among species than within species within lakes, but will be lesser among species than within species among lakes along DOC gradients as a result of different selective environments and sorting of more closely related species with more similar traits. In Abitibi, in the summer 2012, I will perform a field transplant experiment in which crustacean zooplankton communities from four clear lake sources and four DOC-rich lake sources will be incubated in two lakes with different concentrations of dissolved organic carbon. Communities will be subjected to two treatments based on predation by Chaoborus sp. and carbon resources (DOC) that are likely to change as predictions of climate change in boreal zone. These mesocosms will be sampled every week for over two months, and changes in community composition and intra-specific variation in body size and fecundity will be measured.
Interview with Alison Derry in l'UQAM Hebdo