Regulation in ecological systems: an organizational approach

Abstract

The term “regulation” is often used in biology to refer to the means by which a system keeps or returns to a certain state after perturbation. Feedback mechanisms and the propagation of the perturbation through a network of constitutive components are commonly associated with this phenomenon. Intending to produce a full-fledged theoretical account of regulation in organisms, Bich and colleagues have proposed a stricter concept based on the Theory of Biological Autonomy. According to them, regulation is exerted by specialized subsystems that can change the constitutive regime of a living system while their dynamics is not specified by the latter. As such, regulatory subsystems allow faster and more specific responses, enabling the system to deal with a wider range of perturbations and providing greater robustness. In this paper, we extend this approach to ecological systems, showing how regulatory subsystems can be studied as mechanisms above the level of individual organisms belonging to the same species. Moreover, we differentiate between an ecological regulatory mechanism and an organismal regulatory mechanism with ecological consequences . We model an ecological regulatory mechanism that fits into the organizational approach to regulation. The mechanism involves responses to herbivory, in which plants produce volatile compounds to attract predatory insects from different species. We also model a case in which an organismal regulatory mechanism, related to changes in floral phenology, has important ecological consequences. In this manner, we intend to provide a proof of concept for ecological regulatory mechanisms in the strict sense proposed by Bich and colleagues, as well as for their differentiation from organism-level regulatory mechanisms that bring about ecological consequences. We hope this paper spurs further research that develops theoretical understanding of regulation in ecological systems through the investigation of other cases of ecological regulatory mechanisms.