|Metabolic theories in ecology: The Dynamic Energy Budget Theory and the metabolic theory of ecology
In: Fath, B. (Ed.) (2019). Encyclopedia of ecology : Second edition. Elsevier: [s.l.]. ISBN 978-0-444-64130-4. 2780 pp., meer
Metabolic ecology describes the uptake of energy and matter by individual organisms and the subsequent allocation to various life processes such as body maintenance, somatic growth, and reproduction. The ecological role that organisms play is strongly related to their metabolism and understanding the determinants of metabolism is essential to understanding this ecological role. Two alternative and influential theories on metabolic ecology, the dynamic energy budget theory (DEB) and the metabolic theory of ecology (MTE) are described in detail, with a focus on the underlying assumptions and predictive power. Core of the DEB theory concerns the assimilation of food, limited by the surface area of the organism, the transfer into reserves and the allocation of mobilized reserves, also limited by the reserve-structural body interface, to the various life processes. Metabolic rate, i.e., heat production, follows consequentially from making the energy balance. MTE, on the other hand, considers the supply rate of oxygen, limited by a branching fractal network, as setting the pace of life. Fuel will automatically be available. The theories are further compared in terms of complexity and internal consistency. At first sight, DEB seems to be the more complex theory, but if the scope and predictive power are also considered, it appears that DEB cannot be considered as more complex than MTE. The limited scope of MTE, exemplified for example by the ignorance of reproduction and the possibility of variable food intake rate, the lack of internal consistency and the low predictive power, makes it the least efficient theory of the two.