Widespread degradation and limited protection of forests in global tropical dry ecosystems

Despite their ecological and socioeconomic importance, the forested areas of tropical dry ecosystems remain among the most threatened biomes worldwide. There has been limited research on the current extent, fragmentation, and conservation status of tropical dry forests on a global scale. In this study, we used the GLAD UMD Forest Height dataset to provide a high-resolution global assessment of the extent, patch size distribution, and protection levels of Tropical and Subtropical Dry Broadleaf Forests (TBDF) and forested areas of the Tropical and Subtropical Grasslands, Savannas, and Shrublands (TSGSS) by ecoregion and country. We find that despite increasing protection, degradation continues to rise with less than ⅓ of the original TBDF and TSGSS currently forested and over 80 % of those forests currently exposed to edge effects. <1 % of the remaining forest patches are large (>10 km2), and <25 % of the remaining forests are located in conservation or protection zones (TBDF:16 %; TSGSS:21 %), with a heavy protection bias in S.E. Asia. These results indicate high levels of degradation and low conservation leading to potentially severe ecological consequences. Systematic and coordinated efforts are needed to reduce the pressure on this ecosystem and ensure the ongoing provisioning of biodiversity and ecosystem services in these ecoregions.