Colin Thor West–PI. The Sahel of West Africa is a region that suffers from high population densities, frequent severe droughts and enormous stress on natural resources. Because of these challenges, it is the place where the term “desertification” was originally coined. Recently, however, experts have identified large zones of “greening” where the amount of vegetation exceeds what one would expect based on rainfall alone. This pattern is well documented but its mechanisms remain poorly understood. This research will ground-truth Sahelian greening using participatory mapping, linked with high-resolution satellite imagery, to better understand the human role behind regional vegetation trends and its consequences for local livelihoods. It will do so in Burkina Faso where both greening and browning are especially pronounced.