Subsistence lifestyles and insular forest loss in the Louisiade Archipelago of Papua New Guinea: an endemic hotspot

Abstract

Insular areas of the south-west Pacific support high levels of global biodiversity and are undergoing rapid change. The Louisiade Archipelago of Papua New Guinea is a poorly known location with high levels of endemism. The largest island, Sudest Island, supports single-island endemic species and has the largest tract of forest remaining in this island group. The islands still support traditional subsistence lifestyles. This study investigated the patterns of forest loss since 1974 and predicted future forest loss to identify areas of conservation concern. We collected village population census data to assess population growth from 1979–2011. Historical vegetation mapping from 1974 was compared with Global Forest Change data from 2000–14. The geospatial drivers of forest loss were investigated using a generalised linear mixed model. Projected forest cover loss patterns in the islands were modelled in GEOMOD to the year 2030. Resident populations grew rapidly (6.0% per year, 1979–2011) but only a low rate of forest loss (e.g. −0.035% per year, Sudest Island) was observed between 1974 and 2014, restricted to low elevations near villages. Future modelling showed varied impacts on the remaining forest extents of the larger islands. The study offers a rare contemporary example of a biodiverse hotspot that has remained relatively secure. We concluded that local cultural and environmental settings of islands in the south-west Pacific can strongly determine the patterns and processes of forest cover change, and need to be considered in programs to conserve endemic diversity.