1. Asynchronous carbon sink saturation in African and Amazonian tropical forests
- Author
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Gabriela Lopez-Gonzalez, David A. Coomes, Connie J. Clark, Hannsjörg Wöll, Douglas Sheil, Kofi Affum-Baffoe, Geertje M. F. van der Heijden, Katharine Abernethy, Hans Verbeeck, John Tshibamba Mukendi, Ted R. Feldpausch, Terese B. Hart, Sam Moore, Robert Bitariho, Francesco Rovero, Joey Talbot, Lise Zemagho, C. Amani, Jefferson S. Hall, Sean C. Thomas, Amy C. Bennett, Pascal Boeckx, Aida Cuni-Sanchez, Armandu K. Daniels, Fabrice Bénédet, Yadvinder Malhi, Alusine Fofanah, John R. Poulsen, David Kenfack, Lindsay F. Banin, Janvier Lisingo, Hans Beeckman, Jean-Louis Doucet, Eric Chezeaux, Emanuel Gloor, Mireille Breuer-Ndoundou Hockemba, Timothy R. Baker, Jan Reitsma, Vincent P. Medjibe, Christelle Gonmadje, Axel Dalberg Poulsen, Marie Noel Djuikouo Kamdem, Fidèle Baya, Serge K. Begne, Patrick Boundja, Adriane Esquivel-Muelbert, Lucas Ojo, Roel J. W. Brienen, Hermann Taedoumg, Natacha Nssi Bengone, Benjamin Toirambe, Lan Qie, Jon C. Lovett, Greta C. Dargie, Elizabeth Kearsley, Darlington Tuagben, George B. Chuyong, Sylvie Gourlet-Fleury, Fidèle Evouna Ondo, Terry Brncic, Pantaleo K. T. Munishi, Martin J. P. Sullivan, Tommaso Jucker, Simon Willcock, Yannick Enock Bocko, Emanuel H. Martin, Vianet Mihindou, Kelvin S.-H. Peh, Kathryn J. Jeffery, Simon L. Lewis, Emmanuel Kasongo Yakusu, Jean-Remy Makana, Andrew R. Marshall, Martin Gilpin, Bonaventure Sonké, Jeremy A. Lindsell, Faustin M. Mbayu, Corneille E. N. Ewango, Wannes Hubau, Suspense Averti Ifo, Peter M. Umunay, Duncan W. Thomas, Edward T. A. Mitchard, Ernest G. Foli, Lee J. T. White, Jaccques M. Mukinzi, Georgia Pickavance, James Taplin, Terry Sunderland, Annette Hladik, Stephen Adu-Bredu, Jason Vleminckx, Oliver L. Phillips, Sophie Fauset, Alexander K. Koch, David Harris, Miguel E. Leal, Alan Hamilton, Aurora Levesley, Michael D. Swaine, James A. Comiskey, Thalès de Haulleville, John T. Woods, David Taylor, Jim Martin, and Murray Collins
- Subjects
0106 biological sciences ,Carbon Sequestration ,010504 meteorology & atmospheric sciences ,Rainforest ,Carbon sequestration ,Forests ,Atmospheric sciences ,010603 evolutionary biology ,01 natural sciences ,History, 21st Century ,Sink (geography) ,Trees ,chemistry.chemical_compound ,Forest ecology ,Tropical climate ,Life Science ,Biomass ,0105 earth and related environmental sciences ,Carbon dioxide in Earth's atmosphere ,geography ,Tropical Climate ,Multidisciplinary ,geography.geographical_feature_category ,Atmosphere ,Temperature ,Carbon sink ,Carbon Dioxide ,History, 20th Century ,Models, Theoretical ,Droughts ,chemistry ,Carbon dioxide ,Africa ,Environmental science ,C180 Ecology ,Brazil - Abstract
Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 per cent of anthropogenic carbon dioxide emissions1,2,3. Climate-driven vegetation models typically predict that this tropical forest ‘carbon sink’ will continue for decades4,5. Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 tonnes of carbon per hectare per year (95 per cent confidence interval 0.53–0.79), in contrast to the long-term decline in Amazonian forests6. Therefore the carbon sink responses of Earth’s two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature7,8,9. Despite the past stability of the African carbon sink, our most intensively monitored plots suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including carbon dioxide, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly. Overall, the uptake of carbon into Earth’s intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass10 reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth’s climate.
- Published
- 2019
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