The pan-tropical age distribution of regenerating tropical moist forest.

Natural forest regeneration in the tropics is a key element of restoration pledges. Protecting older regenerating forests that already hold substantial carbon and biodiversity value, while promoting natural regeneration in young secondary forests in regions where forests are likely to persist long term, is vital for effective forest restoration. Key questions therefore include understanding the age distribution of naturally regenerating forests pan-tropically and which environmental or socio-economic conditions predict increased longevity in regenerating forests. Here, using a time series of forest cover data (1990-2023) to map the age of regenerating tropical moist forests, we identify 51 Mha of regenerating tropical moist forest, of which >50% is ≤5 years old and under high deforestation pressure, whereas only 6% (3 Mha) is ≥20 years old and located predominantly in the tropical Americas. Location and forest characteristics in the surrounding landscape best predict the age of regenerating forests, with older forests located in areas with high forest integrity and extent, and low forest loss. Realizing the environmental and social values of naturally regenerating forests requires urgent financial, political and societal mechanisms to facilitate the long-term persistence of restoration.