Southeast Asia is home to roughly half of the world’s tropical mountain forests. These highland ecosystems support massive carbon stores and tremendous biodiversity, including a host of species that occur nowhere else on the planet. But new evidence suggests these havens are in grave danger. Conversion of higher-elevation forest to cropland is accelerating at an unprecedented rate throughout the region, according to findings published June 28 in Nature Sustainability.
By analyzing high-resolution satellite data sets of forest loss and state-of-the-art maps of carbon density and terrain, an international team of researchers quantified patterns of forest loss in Southeast Asia during the first two decades of this century. They found that during the 2000s, forest loss was mainly concentrated in the lowlands; but by the 2010s, it had shifted significantly to higher ground.
Between 2001 and 2019, the researchers calculated that Southeast Asia had lost 610,000 square kilometers (235,500 square miles) of forest — an area larger than Thailand. Of this loss, 31% occurred in mountainous regions, equivalent to 189,100 km2 (73,000 mi2) of highland forest converted to cropland and plantation in less than two decades.