ProjectParallel traits and species selection of freshwater zooplankton populations and communities to increased dissolved organic carbon
The interplay between evolution and ecology has increasingly been recognized as a significant factor that can alter trait variation and production in both populations and communities. To understand possible links between evolution in populations and the ecology of associated communities, it is necessary to test whether responses at each of these biological levels occurs in parallel or opposite directions. My study question is: do crustacean zooplankton populations and communities from clear (< 3.0mg/L DOC) versus dark (> 8.0 mg/L DOC) circum-neutral lakes differ similarly in their response to DOC addition? Specifically, I am interested in whether population-level traits (body-size, fecundity) differ between clear and dark lakes in a similar manner as related community-level parameters (secondary production and size-structured community biomass). To investigate possible links between population- and community-level trait variation, I conducted a common garden field mesocosm transplant experiment using three replicate communities from two different lake source types (dark or clear).My prediction was that dark-source zooplankton would show no affect associated with DOC addition, but that clear-source zooplankton would have reduced body size, fecundity, secondary production, and biomass under DOC-enriched conditions. Preliminary results suggest reductions of zooplankton abundance and secondary production irrespective of lake source in a high DOC environment. Testing for more subtle effects of lake origin on population-level traits and community size structure are underway. Quantifying landscape-level variation in zooplankton populations and communities along DOC gradients is a first step for informing us of potential eco-evolutionary responses to DOC enrichment of northern lakes associated with climate change.