Stability of foodwebs and its relation to species diversity.

Abstract The stability of the ecosystem is defined in terms of its ensemble of essentially similar states. This definition, along with the conservation laws of matter and energy, is used to classify the possible mechanisms of ecological stability. These include the development of balance, physiological adaptability (apropos variability in the conditions affecting the use of energy as well as variability in available energy), selective distribution of community fluctuation, and multifunctionality. In particular selective distribution of fluctuation can be achieved through the development of threshold behavior, i.e. sacrifice of energy to detritus pathways. Overlapping multifunctionality coupled with this threshold behavior allows control over the possible pathways of energy flow. The threshold behavior is based on intra- or interspecies communication. The development of these mechanisms in the course of ecological succession is examined under the assumption that the time average of the energy content of the ecosystem tends to a maximum. This development has implications as regards the relative importance of detritus pathways and the number of grazing pathway species during various stages of succession.