Quantifying transportation infrastructure pressure on Southeast Asian World Heritage forests

Abstract

Transportation infrastructure has expanded rapidly in Southeast Asian forests over the last 20 years, opening up remote areas to the degrading effects of internal forest fragmentation and human exploitation. Natural World Heritage sites (NWHS) can be a powerful policy instrument to safeguard tropical forest ecosystems (when adequately implemented and enforced, and communicated to all relevant stakeholders); however, despite this mechanism, transportation infrastructure pressure has been increasing in NWHS forests. Here we propose a novel GIS approach to assess spatial and temporal changes in transportation infrastructure pressure on NWHS in Southeast Asia using a Transportation Infrastructure Pressure Index (TIPI) and forest fragmentation analysis, underpinned by global open-source datasets. Mean pressure in Southeast Asian NWHS is lower than in their surrounding areas (15 km), suggesting that NWHS protection is preventing some deterioration. However, in the last 5 years, these sites have also come under increasing transportation infrastructure pressure (at a mean rate of 14.9% over the period 2014–2019 across 12 sites in Southeast Asia). Furthermore, increases in transportation pressure in NWHS surrounding areas are correlated with increases in transportation pressure inside NWHS. With transportation infrastructure projected to continue to expand globally, GIS-based analysis methods such as these could enhance existing NWHS monitoring efforts, providing early warning about pressures that may be contributing to forest degradation and biodiversity declines in NWHS.