Aboveground forest biomass varies across continents, ecological zones and successional stages: refined IPCC default values for tropical and subtropical forests
This study updates the IPCC’s default aboveground biomass (AGB) values for tropical and subtropical forests, refining estimates using data from over 25,000 plots and global AGB maps. Unlike the broad 2006 values, the 2019 refinements consider ecological zones, successional stages, and uncertainties, highlighting significant variations across regions and forest types. Young secondary forests have 4–7.7 times lower AGB than prior estimates, underscoring the importance of old-growth forests for carbon stock conservation. This reproducible approach enhances accuracy in GHG inventories and encourages data collection in understudied areas.