ABSTRACT
CHAPTER 3 This chapter will present how dynamical mass and energy balances can be used on a canonical community to build a model, offering more information than the usual population dynamic models. The so-called DAB community (Daphnia, Algae, and Bacteria) is used to exemplify the ideas. The dynamics of the simplified community. is constrained by setting up a dynamic mass-and-energy balance for all state variables in the model. This strategy leads to a disclosure of several processes and compound properties that other models, particularly black box models, cannot capture. It is, for instance, clear that assimilation, maintenance, and growth contribute to nitrogen waste. Respiration is usually converted into energy by use of a fixed coefficient, and interpreted as maintenance costs. In the presented dynamic energy budget model all three basic energy fluxes contribute to respiration while the ratio between oxygen consumption and carbon dioxide production is not necessarily constant.
