Accelerating global mountain forest loss threatens biodiversity hotspots

The frontier of forest loss has encroached into mountains in some regions. However, the global distribution of forest loss in mountain areas, which are home to >85% of the world's birds, mammals, and amphibians, is uncertain. Here we combine multiple datasets, including global forest change and selected species distribu-tions, to examine spatiotemporal patterns, drivers, and impacts of mountain forest loss. We find 78 Mha of montane forest was lost during 2001-2018 and annual loss accelerated significantly, with recent losses being 2.7-fold greater than those at the beginning of the century. Key drivers of mountain forest loss include com-mercial forestry, agriculture, and wildfire. Areas with the greatest forest loss overlap with important tropical biodiversity hotspots. Our results indicate protected areas within mountain biodiversity hotspots experi-enced lower loss rates than their surroundings. Increasing the area of protection in mountains should be central to preserving montane forests and biodiversity in the future.

Automated summary

The frontier of forest loss has expanded into mountain areas, but the global distribution of forest loss in mountains remains uncertain. Combining multiple datasets, researchers found that 78 million hectares of montane forest were lost between 2001 and 2018, with an increasing rate of loss. Commercial forestry, agriculture, and wildfires are identified as the major drivers of mountain forest loss, with the most severe loss occurring in important tropical biodiversity hotspots. Protected areas within these hotspots experienced lower loss rates, highlighting the importance of expanding protected areas in mountains to preserve montane forests and biodiversity.