Island biogeography in Southeastern Wisconsin: a progress report.

Abstract

Ecosystems develop as a result of interactions between the biotic and abiotic components in the environment. Natural systems are diverse and stable when interactions between the community and the supersystem are in balance. Change or perturbation in the supersystem will effect a commensurate change in the natural subsystems. Urbanization results in the remaining natural systems becoming isolated within the urban system-a supersystem quite unlike that which gave rise to the natural system. As a result, the natural subsystem must change in the way in which it interacts with its new supersystem to reach equilibrium. A mechanism for such change in natural systems is succession. Successional patterns as a result of urban influences may be quite different than those expected under natural conditions. In order to evaluate these successional patterns, it is necessary to first assess the forest biotic communities when they are embedded and isolated from each other in a non-forest matrix. Crowell (1975) and others, point out that any discontinuous habitat becomes an island. In this context, isolated forested woodlots, embedded in the "agro-urban" matrix, are islands. This study attempts to explain how these forest islands function as a regional forest ecosystem. It will also examine the effects of urbanization on these wildland island communities.