The extent of trees in the tropics

Abstract Remote sensing-based assessments of tree cover and extent provide insight into global and local land use planning. However, there remains considerable uncertainty about the extent of drylands forests and trees in areas with non-forest land use. Here, we present a 10-meter tree extent map for 4.35 billion hectares in the tropics (-23.44° to 23.44° latitude) based on multitemporal composites of Sentinel-1 and Sentinel-2 analyzed with convolutional neural networks. We identify 2,719 million hectares of tropical land with ≥10% tree cover, including 680 million hectares in drylands. We find that 52% of tropical cropland and 46% of tropical urban areas had ≥10% tree cover in 2020. Compared to previous datasets, we demonstrate improved ability to map fragmented and open canopy forests at small spatial scales, especially in drylands, urban areas, and on cropland. As such, this data is expected to enable improved monitoring of tree dynamics at local scales.