Net carbon losses in Central African forests revealed by high-resolution biomass change maps
14 affiliations
- 1Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris Saclay, Gif-sur-Yvette, France. [email protected].
- 2Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris Saclay, Gif-sur-Yvette, France.
- 3Kayrros SAS, Paris, France.
- 4Department of Geoscience and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark.
- 5CRBE, Université de Toulouse, CNRS, IRD, Toulouse INP, Toulouse, France.
- 6European Commission, Joint Research Centre (JRC), Ispra, Italy.
- 7ISPA, UMR 1391 INRAE, Univ. Bordeaux, Villenave d'Ornon, France.
- 8TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, Université de Liège, Gembloux, Belgium.
- 9Department of Earth System Science, Ministry of Education Key Laboratory for Earth System Modeling, Institute for Global Change Studies, Tsinghua University, Beijing, China.
- 10Department of Landscape Architecture and Rural Systems Engineering, Seoul National University, Seoul, Republic of Korea.
- 11State Key Laboratory of Remote Sensing and Digital Earth, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China.
- 12Institute of the Environment and Sustainability, UCLA, Los Angeles, CA, USA.
- 13Ecole Régionale Post-Universitaire d'Aménagement et Gestion Intégrés des Forêts et Territoires Tropicaux (ERAIFT), Kinshasa, Democratic Republic of the Congo.
- 14AMAP, Univ Montpellier, IRD, CIRAD, CNRS, INRAE, Montpellier, France.
Abstract
Dense humid forests in Central Africa hold vast biomass carbon stocks but are increasingly affected by small-scale disturbances that are difficult to detect with current satellite observations. Here, we generate 10 m canopy height maps for 2019-2022 using deep learning with spaceborne lidar and Sentinel-1/ -2 imagery, and derive aboveground biomass changes at 30 m resolution. The maps reveal widespread small disturbance patches, 87% smaller than 1 ha. These account for 48% of biomass carbon gains in regrowing forests and 37% of carbon losses from deforestation. We estimate a net forest carbon loss of -58 ± 14 Tg C yr -1 , with gross losses of -126 ± 21 Tg C yr -1 partially offset by gains of 68 ± 10 Tg C yr -1 . The Democratic Republic of the Congo emerges as a net carbon source (-46 ± 11 Tg C yr -1 ), representing 79% of the regional loss, primarily due to degradation, despite having the largest carbon gains in young secondary forests. Our remote-sensing estimates of national carbon budgets are broadly consistent with country-level inventories and bookkeeping model estimates, paving the way for spatially explicit and transparent carbon monitoring.
Central African forests play a vital role in the global carbon cycle, storing approximately 10% of the world's forest biomass carbon 1-3 . Although intact forests have historically acted as a major carbon sink 4 , recent studies suggest that this sink is weakening, tending toward carbon neutrality or even becoming a net source 5-7 . Disturbances from deforestation, degradation (canopy disturbances that reduce biomass without converting forest to non-forest 8 ), and fragmentation are increasingly affecting these forests 9,10 . At the same time, carbon gains arise from sustainable forestry, restoration, plantations, and forest regrowth following clearing events from shifting cultivation and
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BibTeX
@article{wan2026carbon,
title = {{Net carbon losses in Central African forests revealed by high-resolution biomass change maps}},
author = {Liang Wan and Philippe Ciais and Aurélien de Truchis and Yidi Xu and Martin Brandt and Jérôme Chave and Clément Bourgoin and Jean-Pierre Wigneron and Jean-François Bastin and Wei Li and Youngryel Ryu and Shidong Liu and David Purnell and Ibrahim Fayad and Le Bienfaiteur Sagang and Arthur Vander Linden and Timothée Besisa and Pierre Ploton},
journal = {Nature Communications},
year = {2026},
month = sep,
doi = {10.1038/s41467-026-77531-y},
url = {https://hal.science/hal-05840931v1},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Net carbon losses in Central African forests revealed by high-resolution biomass change maps
AU - Liang Wan
AU - Philippe Ciais
AU - Aurélien de Truchis
AU - Yidi Xu
AU - Martin Brandt
AU - Jérôme Chave
AU - Clément Bourgoin
AU - Jean-Pierre Wigneron
AU - Jean-François Bastin
AU - Wei Li
AU - Youngryel Ryu
AU - Shidong Liu
AU - David Purnell
AU - Ibrahim Fayad
AU - Le Bienfaiteur Sagang
AU - Arthur Vander Linden
AU - Timothée Besisa
AU - Pierre Ploton
PY - 2026
DA - 2026/09/17
JO - Nature Communications
DO - 10.1038/s41467-026-77531-y
UR - https://hal.science/hal-05840931v1
AB - Dense humid forests in Central Africa hold vast biomass carbon stocks but are increasingly affected by small-scale disturbances that are difficult to detect with current satellite observations. Here, we generate 10 m canopy height maps for 2019-2022 using deep learning with spaceborne lidar and Sentinel-1/ -2 imagery, and derive aboveground biomass changes at 30 m resolution. The maps reveal widespread small disturbance patches, 87% smaller than 1 ha. These account for 48% of biomass carbon gains in regrowing forests and 37% of carbon losses from deforestation. We estimate a net forest carbon loss of -58 ± 14 Tg C yr -1 , with gross losses of -126 ± 21 Tg C yr -1 partially offset by gains of 68 ± 10 Tg C yr -1 . The Democratic Republic of the Congo emerges as a net carbon source (-46 ± 11 Tg C yr -1 ), representing 79% of the regional loss, primarily due to degradation, despite having the largest carbon gains in young secondary forests. Our remote-sensing estimates of national carbon budgets are broadly consistent with country-level inventories and bookkeeping model estimates, paving the way for spatially explicit and transparent carbon monitoring. Central African forests play a vital role in the global carbon cycle, storing approximately 10% of the world's forest biomass carbon 1-3 . Although intact forests have historically acted as a major carbon sink 4 , recent studies suggest that this sink is weakening, tending toward carbon neutrality or even becoming a net source 5-7 . Disturbances from deforestation, degradation (canopy disturbances that reduce biomass without converting forest to non-forest 8 ), and fragmentation are increasingly affecting these forests 9,10 . At the same time, carbon gains arise from sustainable forestry, restoration, plantations, and forest regrowth following clearing events from shifting cultivation and
SN - 2041-1723
SN - 2041-1723
ER -