Scale, synthesis and ecosystem dynamics

Abstract

Outlines the behaviour of simple element cycling models in the frequency domain, noting the way in which negative feedback control systems successfully reduce the effects of periodic low frequency inputs, and pointing out that there is an intermediate range of frequencies at which the system dynamics are a major part of the signal that is being measured (and indeed at the highest frequencies the system essentially attenuates the input signal). Hierarchy theory is useful in structuring mathematical models to simulate multi-scale phenomena, and may help reconcile the bottom-up and top-down approaches to studying ecosystems. Within a given time and space scale, the system may be viewed as comprising mechanisms, constraints and phenomena. The importance of scale to the ecosystem ecologist is indicated, and use of the hierarchy approach in forest ecosystem dynamics is shown. -P.J.Jarvis