Amazonian conservation in a changing world

Prioritization of areas for conservation in Amazonia is based on estimates of modern biodiversity and the distribution of endemic species. The refugial hypothesis provided an important conceptual basis for understanding the effects of climatic change on these reserve areas. The hypothesis predicted that ice-age aridity in Amazonia would have been the dominant force that resulted in modern patterns of endemism. However, recent paleoecological data indicate that cooling, rather than drying, was the predominant climatic influence on the ice-age Amazon forests, and this leads to a re-evaluation of forces structuring Amazonian diversity patterns. Modern forest clearance may result in a warmer and drier Amazon basin; conditions now seen to be without past analog. In the light of these data, assumptions regarding the survival of forest isolates in a drying landscape must be revised. Habitat functions in the sense of hydrogeomorphic processes and climate are recommended as conservation goals rather than explicitly attempting to save biodiversity. Reserve areas should be established in the expectation of future climatic change and be large enough to allow the ensuing migration of species. Copyright (C) 1996 Elsevier Science Limited.