Abstract for presentation at Biodiversity Extinction Crisis Conference - A Pacific Response

It has become a basic tenet of conservation biology that fragmentation of native forest results in biodiversity loss. Fragmentation now also looms as a barrier to species' adaptive response to climate change. Re-creation of forest habitat could reverse or avert at least some of the losses that might otherwise occur. But where should the focus of such restoration be? On increasing total area, patch area, number of patches, inter-patch linkages? All of the above? To answer this question requires an understanding of the specific mechanisms causing species' decline in fragmented habitats. However, in spite of a flood of research over the past decade into biodiversity in forest fragments, these mechanisms remain poorly known in practice (other than the clear effects of simple reduction in total area). Nevertheless, there is an increasingly widespread adoption by land managers of the concept of habitat corridors and linkages as the main conservation tool for multiple-use landscapes. In many cases these have become ends in themselves rather than the means to an end of sustaining or increasing biodiversity. Land-use and conservation planners, landscape architects, and property developers have seized upon the green corridor concept, perhaps in the hope of finding a quick fix to a difficult problem. This would not matter if there were no trade-offs in decision-making. A focus on linkages often comes at the expense of other considerations such as total habitat area, patch area, and shape. We will consider this dilemma and use selected examples from our work in the Australian tropics and subtropics to illustrate cases where allocating scarce resources to habitat linkages alone would be unable to avert species' declines, and could be an inappropriate solution to fragmentation problems. We argue that, while functional links can be important, they do not deserve uncritical endorsement.