In Australasia and throughout the world, there is now a rapidly growing drive to restore terrestrial and freshwater environments. Restoration is the process of inducing and assisting abiotic and biotic components of an environment to recover to the state that they existed in the unimpaired or original state (Bradshaw 1997). The original state may mean the state prior to human-induced damage, but in many cases knowledge of such a state is simply not available and return to that state is impossible. The restoration effort may range from restoring populations of a particular species to restoring an entire ecosystem. The goal or target of the restoration effort may be set by the presence of undamaged reference areas, or by reliable historical data, or by the compilation from many fragmentary pieces of evidence of an idealized state or scenario.
Restoration differs from rehabilitation in that the latter seeks to improve the condition of a selected area, but not necessarily in the direction of the pre-existing undamaged state (Bradshaw 1997). Both activities may be carried out either passively (where the degrading forces are abated so that natural recovery processes then drive the restoration) or actively (where not only are the degrading forces abated or stopped but the course of restoration is, to a greater or lesser extent, driven by interventions such as reinstatement of dynamic processes, removal of exotics or reintroduction of species).
In most cases restoration and rehabilitation projects have ecological goals, whether clearly enunciated or not. Restoration, and especially rehabilitation, may have non-ecological goals, such as aesthetic or recreational improvements.
