Introduction

Loss of habitat is perhaps the single largest factor causing the decline of biodiversity (e.g. Wilson 1988; Wilcove et al. 2000). The widespread conversion of natural habitat to human-dominated land uses has left smaller and more isolated islands of natural habitat in a growing sea of agriculture, pasture, managed forests and urbanised areas. About half of the earth's useable land is devoted to pastoral or intensive agriculture (Tilman et al. 2001). Other lands are managed forests or are developed for housing or industrial use. In response, conservation biologists have called for the establishment of a system of formal protected areas to preserve key remnants of remaining natural habitat.

While formal protected areas play a vital role, many conservation biologists and ecologists recognise the need for conservation beyond the boundaries of protected areas (e.g. Franklin 1993; Hansen et al. 1993; Miller 1996; Reid 1996; Wear et al. 1996; Chapin III et al. 1998; Daily et al. 2001; Rosenzweig 2003). Nearly 90 per cent of land across the globe lies outside formal protected areas (IUCN categories I–VI, see WRI 2003), and protected status may arise on lands for reasons other than biodiversity conservation, such as aesthetics or low economic values (Pressey 1994; UNDP et al. 2000; Scott et al. 2001). For these reasons, the consequences of land use and land management decisions in working landscapes outside protected areas are vital.