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Tropical peat composition may provide a negative feedback on fire occurrence and severity.

ABSTRACT: Loss of peat through increased burning will have major impacts on the global carbon cycle. In a normal hydrological state, the risk of fire propagation is largely controlled by peat bulk density and moisture content. However, where humans have interfered with the moisture status of peat either via drainage, or indirectly via climate change, we hypothesise that its botanical composition will become important to flammability, such that peats from different latitudes might have different compositionally-driven susceptibility to ignition. We use pyrolysis combustion flow calorimetry to determine the temperature of maximum thermal decomposition (T_max) of peats from different latitudes, and couple this to a botanical composition analysis. We find that tropical peat has higher T_max than other regions, likely on account of its higher wood content which appears to convey a greater resistance to ignition. This resistance also increases with depth, which means that loss of surface peat in tropical regions may lead to a reduction in the subsequent ignitability of deeper peat layers as they are exposed, potentially resulting in a negative feedback on increased fire occurrence and severity.

SUBMITTER: Crawford AJ

PROVIDER: S-EPMC11349947 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature

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Tropical peat composition may provide a negative feedback on fire occurrence and severity.

Crawford Alastair J AJ Belcher Claire M CM New Stacey S Gallego-Sala Angela A Swindles Graeme T GT Page Susan S Blyakharchuk Tatiana A TA Cadillo-Quiroz Hinsby H Charman Dan J DJ Gałka Mariusz M Hughes Paul D M PDM Lähteenoja Outi O Mauquoy Dmitri D Roland Thomas P TP Väliranta Minna M

Nature communications 20240827 1

Loss of peat through increased burning will have major impacts on the global carbon cycle. In a normal hydrological state, the risk of fire propagation is largely controlled by peat bulk density and moisture content. However, where humans have interfered with the moisture status of peat either via drainage, or indirectly via climate change, we hypothesise that its botanical composition will become important to flammability, such that peats from different latitudes might have different compositio ...[more]

PMID: 39191729

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Tropical peat composition may provide a negative feedback on fire occurrence and severity.

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Tropical peat composition may provide a negative feedback on fire occurrence and severity.

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