Table 1.
Model variables for the phytoplankton biomass, grazer biomass, nutrients, time, and size.
Table 2.
The coefficient and exponent values typically correspond to a and b, respectively, in the allometric relationship r = asb for s the diameter of the cell in μm and r the rate or property. Exceptions include g, which takes the form in Eq (4), h, which takes the form in Eq (5), and c, which takes the form in Eq (7). NA means not applicable.
Table 3.
Variables based on a compilation of size-dependent relationships.
Variables that are a function of several size-dependent relationships, as described in the main text.
Fig 1.
Planktonic biomass for nutrient-phytoplankton-zooplankton model systems with grazers of different sizes.
The model systems include grazers of either 5, 50, or 200 μm diameter, and the multi-consumer model system corresponds to a system with all three sized consumers. The blue symbols correspond to the phytoplankton biomass for each of those systems (diamond for the 5-μm consumer system, upward triangle for 50-μm consumer, downward triangle for 200-μm consumer, and square for multi-consumer system). The yellow symbols correspond to consumer normalized biomass values (circle for the 5-μm consumer, and plus sign for the multi-consumer system). The 50- and 200-μm grazers did not survive in single consumer size class simulations and thus no results are shown.
Fig 2.
Proportion of times consumers grazed different sized phytoplankton during the last 3 years of a ∼ 30 year model run time.
Model run in which the grazers are all a. 5-μm, b. 50-μm or c. 200-μm in diameter, and d. multi-size class grazers with 5-, 50-, and 200-μm grazers combined.
Fig 3.
Changes in the size diversity of the planktonic community among four modeled systems, with each of three consumers separately or all together.
Initial conditions are in the top panels and steady-state solutions in the bottom panels. A keystone predator effect facilitates competitive abilities of different size classed phytoplankton. The most diverse grazer community supports a diverse phytoplankton community. Sizes of symbols are relative sizes and not to scale.