10.5521/FORESTPLOTS.NET/2019_1
Hubau, Wannes
Wannes
Hubau
University of Leeds
Royal Museum for Central Africa
Ghent University
Lewis, Simon
Simon
Lewis
University of Leeds
University College London
Phillips, Oliver
Oliver
Phillips
University of Leeds
Kofi Affum-Baffoe, Kofi
Kofi
Kofi Affum-Baffoe
Hans Beeckman, Hans
Hans
Hans Beeckman
Royal Museum for Central Africa
Cuni-Sanchez, Aida
Aida
Cuni-Sanchez
University College London
University of York
Ewango, Corneille
Corneille
Ewango
Wildlife Conservation Society
Fauset, Sophie
Sophie
Fauset
University of Leeds
Plymouth University
Sheil, Douglas
Douglas
Sheil
Norwegian University of Life Sciences
Mbarara University of Science and Technology
Center for International Forestry Research
Sonké, Bonaventure
Bonaventure
Sonké
Université de Yaoundé I
Sullivan, Martin
Martin
Sullivan
University of Leeds
Sunderland, Terry
Terry
Sunderland
Center for International Forestry Research
University of British Columbia
Thomas, Sean
Sean
Thomas
University of Toronto
Abernethy, Katharine
Katharine
Abernethy
Adu-Bredu, Stephen
Stephen
Adu-Bredu
Amani, Christian
Christian
Amani
Baker, Timothy
Timothy
Baker
Banin, Lindsay
Lindsay
Banin
Baya, Fidèle
Fidèle
Baya
Begne, Serge
Serge
Begne
Bennett, Amy
Amy
Bennett
Benedet, Fabrice
Fabrice
Benedet
Bitariho, Robert
Robert
Bitariho
Bocko, Yannick
Yannick
Bocko
Asynchronous Saturation of the Carbon Sink in African and Amazonian tropical forests
Forestplots.net
2020
CSV data files and R-code
Data and R-code from Hubau W et al. 2020. 'Asynchronous Saturation of the Carbon Sink in African and Amazonian tropical forests'. Nature 579, 80-87. 2020. DOI: 10.1038/s41586-020-2035-0.
ABSTRACT: Structurally intact tropical forests sequestered ~50% of global terrestrial carbon uptake over the 1990s and early 2000s, offsetting ~15% of anthropogenic CO2 emissions1-3. Climate-driven vegetation models typically predict that this tropical forest ‘carbon sink’ will continue for decades4,5. However, recent inventories of intact Amazonian forests show declining carbon sequestration6. Here, we assess the trends in African forests and compare with Amazonia. Records from 244 multi-census plots spanning 11 countries reveal that the carbon sink in aboveground live biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 Mg C ha-1 yr-1 (95% CI: 0.53-0.79). Thus, the carbon sink responses of Earth’s two largest expanses of tropical forest have diverged. As both continents show increasing tree growth (consistent with the expected net effect of rising atmospheric CO2 and air temperature on photosynthesis and respiration7), the divergence arises from differences in carbon losses from tree mortality (no detectable multi-decadal trend in Africa; monotonic increase in Amazonia). Despite the past stability of the African carbon sink, our data suggest a very recent (c. 2010) increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including CO2, temperature, drought, and forest dynamics can account for the observed trends. Extrapolating these predictor variables indicates a long-term decline in the African sink, being 18% smaller in 2030, while the Amazonian sink continues to rapidly weaken, reaching zero in the 2030s. Overall, the uptake of carbon into Earth’s intact tropical forests peaked in the 1990s. Furthermore, this tropical sink is set to end decades sooner than even the most pessimistic vegetation models predict4,5. Observations indicating greater recent carbon uptake into the Northern hemisphere landmass8 reinforce our conclusion that the intact tropical forest carbon sink has already saturated.