Linking physiology to ecology: Towards a new generation of plankton models

Abstract

Understanding how the plankton communities change under varying environmental conditions is crucial to assessing the effects of global change on marine ecosystems. Marine plankton community evolution is generated from the non-linear combination of biotic and abiotic ecosystem forcing and, therefore, is an emergent property and difficult to predict. The adequacy of current modelling approaches for generating emergent properties is discussed and suggestions are made for new directions that may better capture the emergent properties of marine ecosystems. It is suggested that more emphasis is placed on underlying mechanism of cell physiology and foodweb interactions and less on empirical or numerical parameter fitting. Biogeochemistry and ecology can be considered as generated by a limited number of "physiological rules" (photosynthesis, respiration, antioxidant response, autophagy etc.) which are "prescribed" and common to all phytoplanktonic organisms. The challenge is to design a generic cell that captures the essence of key physiological activities (photosynthesis, nutrient and endocytotic uptake, ingestion, respiration, oxyradical defence mechanisms etc.). Once we have such a model cell, we can then define plankton functional types in terms of their capacity to implement each function (i.e. to allocate resources within cellular functions) and hence generate biogeochemical function and ecosystem structure as emergent properties in response to environmental changes. Ultimately, there is a need to think differently and more creatively about how marine ecosystems are modelled. © The Author 2011. Published by Oxford University Press. All rights reserved.