Central African biomass carbon loss counterbalanced by carbon gains during 2010-2019

Posted by Design Studio

26 June 2024

Challenge 1: Tree Biomass


Tropical vegetation stores a large amount of carbon but has suffered from natural and anthropogenic disturbances in recent decades. With the second largest tropical moist forests and widespread savannas, Africa plays an important role in the tropical carbon budget. Despite carbon emissions from deforestation and forest degradation, terrestrial vegetation in Central Africa appears to have acted as a small net carbon sink in recent decades due to slow carbon uptake by vegetation growth and recovery. However, the respective impacts of the natural and anthropogenic factors on the biomass changes are still unclear, because of the paucity of large-scale and long-term direct observations of disturbances and time series of biomass carbon stocks in this region.


Methods: Machine-learning attribution of drivers of aboveground carbon changes

A team of researchers working in the CALIPSO project has estimated that aboveground carbon (AGC) changes in Central Africa from 2010 to 2019 using satellite data. We first quantified the impact of deforestation on AGC by combining high-resolution forest cover loss data with biomass maps. The difference between total AGC changes and deforestation losses allowed us to identify other factors affecting AGC, like disturbances and recovery processes. We then analyzed the drivers of these non-deforestation AGC changes using a machine-learning method.


Results & Conclusion

During 2010-2019, deforestation induced a gross AGC loss of 102.2±17.1 TgC yr-1, which was counterbalanced by an AGC increase of 116.9±41.1 TgC yr-1, leading to a net gain of 14.6±3.8 TgC yr-1. Compared to anthropogenic and soil factors, changes in climate-related factors (e.g., radiation) are more important for the non-deforestation AGC changes. A large AGC increase was found in the northern savannas. In moist forests, strong biomass recovery and growth largely compensated the carbon loss from deforestation and degradation. Considering the increasing resource demand due to rapid population growth, reconciling natural conservation and economic development in Central Africa remains challenging and depends on climate changes and country-specific social-economic conditions.

Schematic of aboveground biomass carbon budget, the analyzed drivers and methods during 2010-2019 in Central Africa.


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