Parks protect forest cover in a tropical biodiversity hotspot, but high human population densities can limit success

Abstract

Maintaining forest cover is important for Biodiversity Hotspots that support many endangered and endemic species but have lost much of their original forest extent. In developing countries, ongoing economic and demographic growth within Hotspots can alter rates and patterns of deforestation, making it a concern to quantify rates of forest loss and assess landscape-scale correlates of deforestation within Hotspots. Such analyses can help set baselines for future monitoring and provide landscape-scale perspectives to design conservation policy. For the Western Ghats Biodiversity Hotspot in India, we examined correlates of forest loss following rapid economic expansion (post-2000 CE). First, we used open-source remote-sensing data to estimate annual trends in recent forest loss (from 2000 to 2016) for the entire Hotspot. Across the entire Western Ghats, we assessed the relative importance of and interactions among demographic, administrative, and biophysical factors that predicted rates of forest loss—measured as the number of 30 × 30-m pixels of forest lost within randomly selected 1 km2 cells. Protected areas reduced forest loss by 30%, especially when forests were closer to roads (33%) and towns (36%). However, the advantage of protection declined by 32% when local population densities increased, implying that the difference in forest loss between protected and non-protected areas disappears at high local population densities. To check scale-dependency of spatial extent, we repeated the modelling process for two landscape subsets within Western Ghats. In contrast with results for the entire Western Ghats, both focal landscapes showed no difference in deforestation with protection status alone or its interactions with village population density and distance to towns. However, deforestation was 88% lower when forests were protected and farther from roads. Overall, our results indicate that protected areas help retain forest cover within a global Biodiversity Hotspot even with rapid development, but high human population densities and road development can reduce the benefits of protection.