Optimal allocation backs droop's cell-quota model

Abstract

Droop's cell-quota model is the most successful description of phytoplankton growth in laboratory cultures and is increasingly being introduced into the ecosystem components of biogeo -chemical models. Although the Droop model's para -meters can be easily interpreted in biological terms, it was nevertheless derived empirically and lacks a sound mechanistic foundation. Here we derive Droop's model from a simple optimality condition which maximises net growth rate. Our approach links the maximum cell quota to the cost of nutrient acquisition and suggests that respiration is influenced more strongly by C fixation than by N assimilation. © Inter-Research 2013.