A sample from a Carapa procera tree dating back to Belgian colonial rule, now in the collection of the Botanical Garden of Mbandaka, in Mbandaka, Democratic Republic of Congo, Oct. 24, 2021. The area's swamps are part of the biggest network of tropical peatlands in the world -- 55,000 square miles of Central Africa that store more than 30 billion tons of carbon. (Nanna Heitmann/The New York Times)