AIMS AND LIMITS OF ECOLOGICAL MODELING EXEMPLIFIED BY ISLAND THEORY

A classification of ecological models into two types is presented. Descriptive models condense field data into a concise form and can be used for predictions. Simulation models are constructed to provide an understanding. Very complex modelling exhibits several shortcomings. Models should concentrate on a specific goal and should be kept simple. These general ideas are exemplified by the power law for the species number-area relationship of island biogeography. Extinction and recolonization of populations are modelled with the inclusion of demographic and environmental noise. By including interspecific competition the power law is deduced. In addition, the species number-abundance distribution is found to be lognormal.