The legacy of post-Columbian disturbance in shaping a northwestern Amazonian forest

The ecological legacies of past human activity in modern Amazonian forests remain debated. Paleoecology helps provide long-term insights into land management practices and their ecological consequences. We analyzed fossil pollen, charcoal, phytoliths, and sediment chemistry from Añangucocha, a lake in Ecuadorian Amazonia, identifying six distinct phases of cultural use over the last 1120 years. All past cultural uses influenced vegetation composition, but the most persistent impact resulted from the intensification of fire after c. 1620 CE. The last episode of fire activity occurred c. 1900 CE, and the forest remains in a state of succession. Our findings challenge the prevailing view that most ecological legacies in Amazonian forests derive from pre-Columbian land use. Instead, we highlight the dominant role of post-Columbian disturbances, particularly fire, in shaping modern forest composition.