Danielsdottir, M. G. University of Washington, firstname.lastname@example.org
Brett, M. G. University of Washington, email@example.com
A MATHEMATICAL ANALYSIS OF FOOD QUALITY IMPACTS ON TROPHIC COUPLING
Recent analysis show high variability in the strength of food-web interactions in planktonic ecosystems, and several authors have suggested this is due to variation in food quality at the plant herbivore interface. We used a Lotka-Volterra modeling approach to test the hypothesis that variation in phytoplankton food quality may be a determinant of the strength of trophic interactions. The quasi-equilibrium zooplankton to phytoplankton biomass (Z/P) ratio was calculated as an index of the potential strength of trophic interactions. The model was run with the zooplankton growth efficiency varying from 4% to 64%. The Z/P ratio varied exponentially with the growth efficiency. Although the zooplankton community becomes somewhat self-limiting at high zooplankton biomass, high algal food-quality allows the zooplankton community to sustain a very high biomass at high growth efficiencies. These results indicate that the food-quality of the phytoplankton can dramatically affect the strength of trophic coupling and how phytoplankton production is transferred through the food web.
Day: Wednesday, Feb. 3
Location: Sweeney Center