The Conservation of Habitat and Landscape

In this chapter you will learn:

• 1. Concepts and definitions of habitat and landscape and the role of habitat conservation in conservation biology

• 2. Definitions of habitat heterogeneity and patch dynamics

• 3. Specific mechanisms through which habitat loss, fragmentation, and isolation threaten biodiversity

• 4. Principles of reserve design and their role in habitat conservation

• 5. Means of reducing the impacts of human disturbance to conserve habitat and habitat-dependent populations in non-reserve environments

Habitat can be defined as the physical and biological surroundings of an organism (Bolen and Robinson 1995) or, more precisely, as sites having appropriate levels of the biotic and abiotic features required by a species for survival and reproduction (Pearson 2002). That is, habitats are arrangements of resources that meet the needs of individual species. Although we often “name” habitats according to the dominant vegetation present in them (for example, “sagebrush habitat,” “grassland habitat,” or “forest habitat”) we should recognize from the outset that the vegetation communities we might use to label habitats are not the same as the habitat itself, although they may be associated with it. Habitats are usually conceived as occurring in patches, which can be defined as contiguous regions of the same kind of habitat (Pearson 2002) or as sites where the habitat conditions of a species are realized. Patches often exist in networks in which a collection of spatially distinct patches is connected by linear elements (structural definition) and linked by a flow of individuals from patch to patch (functional definition) (Opdam 2002:318). If this is what we mean by “habitat,” what do we mean by “landscape?”