PLANKTONIC BIOMASS SIZE SPECTRA: AN EMERGENT PROPERTY OF SIZE-DEPENDENT PHYSIOLOGICAL RATES, FOOD WEB DYNAMICS, AND NUTRIENT REGIMES
The systematic change in a trait with size is a concise means of representing the diversity and organization of planktonic organisms. Using this simplifying principle, we will present three size-structured nutrient-phytoplankton-zooplankton (NPZ) models of increasing grazing complexity and examine the influence of physiological rates, trophic dynamics, and nutrient regime on the emergent size structuring of planktonic communities. To parameterize our models, we use a synthesis of literature values. Using these parameterizations, all models produce realistic planktonic size distributions, which increase in size range and biomass with increasing total nutrient concentrations. Under all combinations of grazing complexity and total nutrient concentration, both the phytoplankton and zooplankton have generally decreasing normalized biomass spectral slopes that are only weakly affected by changes in trophic dynamics. Using a sensitivity analysis, we found that changes in the size-dependence of the zooplankton grazing rate has the largest influence on the phytoplankton and zooplankton biomass. The creation of planktonic biomass spectra with properties observed in nature supports the use of size-dependent rates in general, and the model parameterizations provide values for use in other plankton community models.
Taniguchi, D., Scripps Institution of Oceanography, UCSD, USA, email@example.com
Franks, P., Scripps Institution of Oceanography, UCSD, USA, firstname.lastname@example.org
Poulin, F. J., University of Waterloo, Canada, email@example.com
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall
Presentation is given by student: No