Drivers of soil heterotrophic respiration in tropical peatlands: a review to inform peat carbon accumulation modelling

Globally peatlands store 25% of global soil organic carbon but this large carbon store is at risk under climate change and from widespread anthropogenic disturbances. The impact of climate change on tropical peatlands, which represent 23%–30% of the global peatland area, is particularly poorly under...

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Main Authors: Elise M. Dehaen, Eleanor J. Burke, Sarah E. Chadburn, Jörg Kaduk, Stephen Sitch, Noah D. Smith, Angela V. Gallego-Sala
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-04-01
Series:Frontiers in Geochemistry
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Online Access:https://www.frontiersin.org/articles/10.3389/fgeoc.2025.1492386/full
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author Elise M. Dehaen
Eleanor J. Burke
Sarah E. Chadburn
Jörg Kaduk
Stephen Sitch
Noah D. Smith
Angela V. Gallego-Sala
author_facet Elise M. Dehaen
Eleanor J. Burke
Sarah E. Chadburn
Jörg Kaduk
Stephen Sitch
Noah D. Smith
Angela V. Gallego-Sala
author_sort Elise M. Dehaen
collection DOAJ
description Globally peatlands store 25% of global soil organic carbon but this large carbon store is at risk under climate change and from widespread anthropogenic disturbances. The impact of climate change on tropical peatlands, which represent 23%–30% of the global peatland area, is particularly poorly understood and Earth System Models do not yet include a suitable representation of the soil carbon cycle for tropical peatlands. Peat decomposition via soil heterotrophic respiration to CO2 (SHR-CO2) is a main component of the peatland carbon cycle. However, the lack of consensus on the importance of different drivers and the scarcity of empirical data hinders model development. Therefore, this study reviews the drivers of SHR-CO2 (moisture, temperature, decomposability and, nutrients and decomposers) for tropical peatlands. We compile available empirical data to inform model development; and highlight priorities for future experimental work that would enable further model refinement. We point out that the sharp decrease of SHR-CO2 under anoxic water-saturated conditions is a major parameter for tropical peat decomposition and the ratio of SHR-CO2 under anoxic conditions to the SHR-CO2 at the optimum moisture is 0.10 ± 0.08. Additionally, we highlight that, at present, the common assumption that SHR-CO2 doubles with an 10°C increase (Q10 of ca. 2) remains the most parsimonious option considering the lack of empirical data to establish a more process-based peatland SHR-CO2 temperature relationship. Finally, we identify three priorities to advance tropical peatland model improvement: (1) narrowing the constraint on the optimum moisture range for SHR-CO2 in tropical peatlands, (2) investigating the interaction between moisture and temperature sensitivity, and (3) identifying the most widely applicable metric to characterise peat decomposability that might enable quantitative comparison across the tropics.
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spelling doaj-art-cde930144f234a4aa1e1cd574e670aff2025-08-20T03:05:43ZengFrontiers Media S.A.Frontiers in Geochemistry2813-59622025-04-01310.3389/fgeoc.2025.14923861492386Drivers of soil heterotrophic respiration in tropical peatlands: a review to inform peat carbon accumulation modellingElise M. Dehaen0Eleanor J. Burke1Sarah E. Chadburn2Jörg Kaduk3Stephen Sitch4Noah D. Smith5Angela V. Gallego-Sala6Department of Geography, University of Exeter, Exeter, United KingdomMet Office Hadley Centre, Exeter, United KingdomDepartment of Mathematics, University of Exeter, Exeter, United KingdomSchool of Geography, Geology and the Environment, University of Leicester, Leicester, United KingdomDepartment of Geography, University of Exeter, Exeter, United KingdomDepartment of Geography, University of Exeter, Exeter, United KingdomDepartment of Geography, University of Exeter, Exeter, United KingdomGlobally peatlands store 25% of global soil organic carbon but this large carbon store is at risk under climate change and from widespread anthropogenic disturbances. The impact of climate change on tropical peatlands, which represent 23%–30% of the global peatland area, is particularly poorly understood and Earth System Models do not yet include a suitable representation of the soil carbon cycle for tropical peatlands. Peat decomposition via soil heterotrophic respiration to CO2 (SHR-CO2) is a main component of the peatland carbon cycle. However, the lack of consensus on the importance of different drivers and the scarcity of empirical data hinders model development. Therefore, this study reviews the drivers of SHR-CO2 (moisture, temperature, decomposability and, nutrients and decomposers) for tropical peatlands. We compile available empirical data to inform model development; and highlight priorities for future experimental work that would enable further model refinement. We point out that the sharp decrease of SHR-CO2 under anoxic water-saturated conditions is a major parameter for tropical peat decomposition and the ratio of SHR-CO2 under anoxic conditions to the SHR-CO2 at the optimum moisture is 0.10 ± 0.08. Additionally, we highlight that, at present, the common assumption that SHR-CO2 doubles with an 10°C increase (Q10 of ca. 2) remains the most parsimonious option considering the lack of empirical data to establish a more process-based peatland SHR-CO2 temperature relationship. Finally, we identify three priorities to advance tropical peatland model improvement: (1) narrowing the constraint on the optimum moisture range for SHR-CO2 in tropical peatlands, (2) investigating the interaction between moisture and temperature sensitivity, and (3) identifying the most widely applicable metric to characterise peat decomposability that might enable quantitative comparison across the tropics.https://www.frontiersin.org/articles/10.3389/fgeoc.2025.1492386/fulltropical peatsoil heterotrophic respirationcarbon dioxidetemperature sensitivitymoisture effectprocess-based models
spellingShingle Elise M. Dehaen
Eleanor J. Burke
Sarah E. Chadburn
Jörg Kaduk
Stephen Sitch
Noah D. Smith
Angela V. Gallego-Sala
Drivers of soil heterotrophic respiration in tropical peatlands: a review to inform peat carbon accumulation modelling
Frontiers in Geochemistry
tropical peat
soil heterotrophic respiration
carbon dioxide
temperature sensitivity
moisture effect
process-based models
title Drivers of soil heterotrophic respiration in tropical peatlands: a review to inform peat carbon accumulation modelling
title_full Drivers of soil heterotrophic respiration in tropical peatlands: a review to inform peat carbon accumulation modelling
title_fullStr Drivers of soil heterotrophic respiration in tropical peatlands: a review to inform peat carbon accumulation modelling
title_full_unstemmed Drivers of soil heterotrophic respiration in tropical peatlands: a review to inform peat carbon accumulation modelling
title_short Drivers of soil heterotrophic respiration in tropical peatlands: a review to inform peat carbon accumulation modelling
title_sort drivers of soil heterotrophic respiration in tropical peatlands a review to inform peat carbon accumulation modelling
topic tropical peat
soil heterotrophic respiration
carbon dioxide
temperature sensitivity
moisture effect
process-based models
url https://www.frontiersin.org/articles/10.3389/fgeoc.2025.1492386/full
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