CHAOS IN ECOLOGY - IS MOTHER-NATURE A STRANGE ATTRACTOR

We review the role of chaos and the study of chaos in ecology. We use sensitive dependence on initial conditions as the best heuristic definition of chaos. This definition forms the common theme for our review of approaches for demonstrating the importance of chaos in ecology. We emphasize that this definition of chaos can include the effects of noise, and that there is no dichotomy between stochasticity and chaos. We review three classes of approaches for studying chaos in ecology: models, analysis of time series, and experiments. Current ideas from modelling approaches demonstrate the plausibility of chaos. New approaches for analyzing time series are based on using the presence of a positive Lvapunov exponent to indicate sensitive dependence on initial conditions. The methods can deal with relatively short time series that include the effects of noise, with chaotic dynamics appearing in at least some cases. Experimental work is just beginning, spurred by modelling results and the new methods for analyzing times series. We suggest directions tor further work in each of these approaches.