The Margalef’s Mandala: a legacy continuously evolving

Abstract

The Margalef’s Mandala visualizes in a two-dimensional space the role of nutrients and turbulence in shaping the phytoplankton communities. This Mandala, published in 1978, comprises fundamental concepts of plankton ecology related to species succession and energy fluxes. During forty years this conceptual framework has been continuously evolving and numerous authors adapted it to integrate the variety of processes underlying plankton dynamics at different spatio-temporal scales. We now know that turbulence affects different interactions and activities of plankton components such as predator-prey encounter rates and nutrient uptake by osmotrophs. These processes also depend on the nutrient load for a particular system and ultimately determine ecosystem metabolism. We show empirical evidence of plankton responses to turbulence under a range of nutrient concentration and osmotroph abundance conditions. These data led to building-up an extended version of Margalef’s mandala, that we call “the fan”, applicable to system metabolism