Equilibrium and Nonequilibrium Models in Ecological Anthropology: An Evaluation of “Stability” in Maring Ecosystems in New Guinea

Abstract

Three models pertaining to the stability of Maring ecosystems have been proposed. The first is the local stability model, in which a population seeks its own equilibrium state; the second is the regional stability model, in which each population is ultimately unstable, but populations persist somewhere in space; and the third is the disequilibrium model, in which neither stability nor population regulation is attained. In the disequilibrium model, exogenous factors prevent a population, which is moving toward some equilibrium state, from reaching it. The large number of quantitative anthropological and ecological studies in Highlands New Guinea has not shown clearly which of these three models best describes reality. Simulation of shifting agriculture in New Guinea shows that the Highlands systems are equilibrium‐seeking, but have such limited recovery rates from disturbance that even small perturbations are sufficient to keep them from reaching equilibrium. When the influences of technological innovation, environmental change, and social‐cultural evolution are taken into account, the disequilibrium model is the model of choice. These systems remain away from their stable equilibrium points most of the time, if those exist at all. Thus, New Guinea agroecosystems can be stable or unstable depending upon how stability is defined.