EGU22-9740
https://doi.org/10.5194/egusphere-egu22-9740
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

What is the current and future carbon sink potential of recovering secondary and degraded forests across the humid tropics?

Viola Heinrich1, Christelle Vancutsem2,3, Ricardo Dalagnol4,5, Thais Rosan6, Dominic Fawcett6, Celso Silva Junior4,7, Frédéric Achard8, Tommaso Jucker9, Jo House1, Stephen Sitch6, Tristram Hales10, and Luiz Aragão4,6
Viola Heinrich et al.
  • 1University of Bristol, School of Geographical Sciences, Bristol, United Kingdom of Great Britain – England, Scotland, Wales (viola.heinrich@bristol.ac.uk)
  • 2FINCONs group, Milan, Italy
  • 3Center for International Forestry Research (CIFOR), Bogor, Indonesia
  • 4Earth Observation and Geoinformatics Division, National Institute for Space Research (INPE), São José dos Campos, Brazil.
  • 5Department of Geography, School of Environment Education and Development, University of Manchester, Manchester, UK.
  • 6College of Life and Environmental Sciences, University of Exeter, Exeter, UK.
  • 7Departamento de Engenharia Agrícola, Universidade Estadual do Maranhão (UEMA), São Luís, Brazil
  • 8European Commission, Joint Research Centre, Ispra, Italy.
  • 9School of Biological Sciences, University of Bristol, Bristol UK.
  • 10Sustainable Places Research Institute, Cardiff University, Cardiff, UK.

The Forest and Land use Declaration negotiated at the 26th climate Conference of the Parties (COP) in Glasgow, November 2021, confirmed that Tropical Moist Forests (TMFs) are a vital nature-based solution to addressing the climate and ecological emergencies. TMFs are estimated to be a net sink of carbon, storing approximately 0.8 Pg C yr-1 [1]. However, the size of this sink is declining due to human activities such as deforestation and forest degradation through logging and fire, as well as climate variability and change1. Tropical forests are therefore a patchwork of undisturbed, degraded, and secondary forests, creating regionally complex patterns of growth and carbon storage.

While there have been numerous studies exploring and quantifying the recovery rates of secondary forests, quantifying the recovery rate of degraded forests has been largely unexplored on a pan-tropical scale. In this study, we address this knowledge gap by quantifying the carbon accumulation in recovering degraded forests as well as secondary forests, which collectively, we have termed “Recovering Forests”.

Recent advances in remote sensing products have made it possible to (i) observe and distinguish degraded forests from undisturbed and secondary forests2; and (ii) estimate the carbon sequestration rates within these forests3,4.

Here we use a combination of remote sensing derived products in a space-for-time substitution approach to quantify the carbon accumulation rates in recovering forests. This includes recovering degraded forests and secondary forests in the three major tropical biomes: the Amazon Basin, Island of Borneo and Congo Basin.

Our results show growth rates to be the highest in Borneo, in recovering degraded forests5. We attribute these inter-biome/forest variations in growth to differences in disturbance and find that environmental variables such as water deficit and temperature influence the recovery of forests in unique ways across the tropics. We also provide estimates of the current and future carbon sink of recovering forests across the three biomes.

We find that recovering degraded forests have a large carbon sink potential, owing largely to their vast areal extent (10% of forest area). Secondary forests, regrow across a smaller land area (2%) but have faster growth rates (up to 30% faster in the Amazon basin) compared to degraded forest recovery. Additionally, we find that 35% of degraded forest are subject to subsequent deforestation2,5, emphasizing the need for continuous monitoring as well as their protection to safeguard the carbon stock in all recovering forests. Our results provide insights into the dynamic patterns of tropical forest recovery, influenced by interactions of humans and the environment that have the potential to improve global vegetation models as well as help to inform national forest inventories.

References:

1 Hubau, W. et al. Nature 579, 80–87 (2020).

2 Vancutsem, C. et al. Sci. Adv. 7, eabe1603 (2021).

3 Santoro, M. & Cartus, O. Centre for Environmental Data Analysis  (2021). 

4 Heinrich, V. H. A. et al.  Nature Commun. 12, 1785 (2021).

5 Heinrich, V. H.A. et al. One quarter of humid tropical forest loss offset by recovery. (in Review).

How to cite: Heinrich, V., Vancutsem, C., Dalagnol, R., Rosan, T., Fawcett, D., Silva Junior, C., Achard, F., Jucker, T., House, J., Sitch, S., Hales, T., and Aragão, L.: What is the current and future carbon sink potential of recovering secondary and degraded forests across the humid tropics?, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9740, https://doi.org/10.5194/egusphere-egu22-9740, 2022.

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