Three decades of deforestation in southwest Sumatra: Have protected areas halted forest loss and logging, and promoted re-growth?

Much of the forest cover in southern Sumatra, Indonesia has been cleared since the early 1970s, but accurate estimates of the scales and rates of loss are lacking. This study combined high-quality remote sensing applications and extensive field surveys, both to provide an accurate picture of deforestation patterns across an area of 1.17 million ha in southwest Sumatra and to assess whether southwest Sumatra’s Bukit Barisan Selatan National Park (BBSNP) has halted forest loss and logging, and promoted re-growth, since its creation in 1984. Of the single large (692,850 ha) contiguous area of forest standing across our study area in 1972, nearly half (344,409 ha) has been cleared from 1972 to 2002, at an average rate per original forest cover of 1.69% y⁻¹. In Gunung Raya Wildlife Sanctuary (GRWS) and Hydrological Reserves (HR), forests have shrunk by 28,696 ha and 113,105 ha, at an average rate of 2.74% y⁻¹ and 2.13% y⁻¹, respectively. In contrast, forests in BBSNP have reduced four times more slowly than those in GRWS and HR, and have shrunk by 57,344 ha, at an average rate of 0.64% y⁻¹. Nevertheless, the forests within BBSNP were cleared almost as rapidly during the post-establishment, as during the pre-establishment, period (0.65% y⁻¹ and 0.63% y⁻¹, respectively) despite the introduction of protection measures during the post-establishment period, following the government’s pledge to expand and protect Indonesia’s network of Protected Areas (PAs) at the 1982 Bali World Parks Congress. While these protection measures failed to slow down rates of forest loss caused by agricultural encroachments they reduced large-scale mechanised logging by a factor of 4.2 and stabilized some 8610 ha of agricultural encroachments, enabling forest re-growth.