Forests in Darien, an eastern province of Panama, are crucial for carbon storage, biodiversity conservation and the livelihoods of indigenous groups, yet they are under threat due to illegal logging. Through a participatory forest-carbon monitoring project, scientists from the Smithsonian Tropical Research Institute (STRI), McGill University and the National Research Council of Canada uncovered sources of above-ground biomass (AGB) variation and explored considerations for implementing Reducing Emissions from Deforestation and Forest Degradation (REDD+) in Darien.