Corridors among habitat fragments (frequently recommended for
non-genetic reasons) can re-establish gene flow among isolated populations.
Species vary in their requirements for a corridor to be an effective
migration path (Lindenmayer & Nix 1993). The most ambitious proposal
of this kind is ‘The Wildlands Project’ – to provide corridors from north
to south in North America (Davis 1992). The corridors will link existing
reserves and surround both reserves and corridors with buffer zones
that are hospitable to wild animals and plants. The time frame for
achieving this vision is hundreds of years, given the political, social and
financial challenges. None the less, such systems are essential if we are
to conserve biodiversity in the long term. With global climate change,
plants and animals need to alter their distributions to cope with moving
climatic zones. At present, such movement is largely prevented by
inhospitable habitat between reserves and protected areas.