The expansion of tree plantations across tropical biomes

Abstract

Across the tropics, recent agricultural shifts have led to a rapid expansion of tree plantations, often into intact forest and grassland habitats. However, this expansion is poorly characterized. Here we report tropical tree plantation expansion between 2000 and 2012, based on classifying nearly 7 million unique patches of observed tree cover gain using optical and radar satellite imagery. Most observed gain patches (69.2%) consisted of small patches of natural regrowth (5.9 ± 0.2 Mha). However, expansion of tree plantations dominated observed increases in tree cover across the tropics (11.8 ± 0.2 Mha) with 92% of plantation expansion occurring in biodiversity hotspots and 14% in arid biomes. We estimate that tree plantations expanded into 9.2% of accessible protected areas across the humid tropics, most frequently in southeast Asia, west Africa, and Brazil. Given international tree planting commitments, it is critical to understand how future tree plantation expansion will affect remaining natural ecosystems.

One Sentence Summary: Tree plantations dominated recent expansions of tropical tree cover, including into 9% of accessible parks in the humid tropics.