Deforestation and degradation in Papua New Guinea: a response to Filer and colleagues, 2009

Abstract

Papua New Guinea’s (PNG) forests are a vital natural resource for the human population that they sustain, the wide biological diversity they contain, the ecological services they provide and their global role in maintaining climatic processes (Hunt, 2006; Bryan et al., in press). The population of PNG is expanding by approximately 2–3% annually, requiring forest clearance for subsistence cultivation, and over recent decades the log export industry has expanded greatly. Though these and other drivers of forest change are well known, there has been considerable debate regarding the extent and rate at which forests are being degraded or converted to other forms of land use. This debate has been fuelled by an absence of recent accurate data, and coloured by the politics associated with industrial rainforest exploitation and more recently, carbon-related REDD projects1. To address this deficiency we undertook a 6-year research project that involved mapping the entire PNG forest estate at high resolution, and compared this with maps from the early 1970s. Our results provide detailed, accurate measurement of the area and condition of forest in PNG, how much forest has been cleared or degraded over the past three decades, and what caused these changes. Our research was initially published as a detailed report (Shearman et al., 2008) that has also been published, in abbreviated form, in the peerreviewed journal Biotropica (Shearman et al., 2009). Our most controversial finding was that overall rates of forest clearance and degradation were much higher than those estimated in the early 1990s (Hammermaster and Saunders, 1995; McAlpine and Quigley, 1998; McAlpine and Freyne, 2001). This is partly because the rates are accelerating but it is mostly due to technical differences in measuring forest cover and forest cover change.