Defining the conservation value of secondary tropical forests

Abstract

Over the last 50 years, tropical forests have been exploited for timber extraction, cleared for agriculture, pasture and roads and degraded by wildfires and overhunting (Laurance & Peres, 2006; Sodhi et al., 2007). The result of these processes is that human-modified landscapes, composed of a mosaic of old-growth (OG) forest fragments, degraded forest, regenerating forest and agricultural land, now cover large areas of the tropics (Gardner et al., 2009). Although large expanses of OG forest remain and 9.8% of the tropical forest biome is protected within strict reserves, recent estimates suggest that there is now a larger area of secondary and degraded tropical forest than there is undisturbed OG (FAO, 2006; Schmitt et al., 2008; Brooks et al., 2009). Therefore, the long-term conservation of tropical forest biodiversity is dependent on the capacity of human-modified landscapes tomaintain viable populations of tropical forest species.