Biomass consumption by surface fires across Earth's most fire prone continent

Brett P. Murphy, Lynda D. Prior, Mark A. Cochrane, Grant J. Williamson, David M.J.S. Bowman

    Research output: Contribution to journalArticleResearchpeer-review

    Abstract

    Landscape fire is a key but poorly understood component of the global carbon cycle. Predicting biomass consumption by fire at large spatial scales is essential to understanding carbon dynamics and hence how fire management can reduce greenhouse gas emissions and increase ecosystem carbon storage. An Australia-wide field-based survey (at 113 locations) across large-scale macroecological gradients (climate, productivity and fire regimes) enabled estimation of how biomass combustion by surface fire directly affects continental-scale carbon budgets. In terms of biomass consumption, we found clear trade-offs between the frequency and severity of surface fires. In temperate southern Australia, characterised by less frequent and more severe fires, biomass consumed per fire was typically very high. In contrast, surface fires in the tropical savannas of northern Australia were very frequent but less severe, with much lower consumption of biomass per fire (about a quarter of that in the far south). When biomass consumption was expressed on an annual basis, biomass consumed was far greater in the tropical savannas (>20 times that of the far south). This trade-off is also apparent in the ratio of annual carbon consumption to net primary production (NPP). Across Australia's naturally vegetated land area, annual carbon consumption by surface fire is equivalent to about 11% of NPP, with a sharp contrast between temperate southern Australia (6%) and tropical northern Australia (46%). Our results emphasise that fire management to reduce greenhouse gas emissions should focus on fire prone tropical savanna landscapes, where the vast bulk of biomass consumption occurs globally. In these landscapes, grass biomass is a key driver of frequency, intensity and combustion completeness of surface fires, and management actions that increase grass biomass are likely to lead to increases in greenhouse gas emissions from savanna fires.

    Original languageEnglish
    Pages (from-to)254-268
    Number of pages15
    JournalGlobal Change Biology
    Volume25
    Issue number1
    Early online date6 Nov 2018
    DOIs
    Publication statusPublished - Jan 2019

    Fingerprint

    Fires
    Biomass
    Earth (planet)
    biomass
    Carbon
    savanna
    Gas emissions
    Greenhouse gases
    greenhouse gas
    fire management
    net primary production
    consumption
    continent
    carbon
    combustion
    grass
    carbon budget
    carbon cycle
    carbon sequestration
    trade-off

    Cite this

    Murphy, B. P., Prior, L. D., Cochrane, M. A., Williamson, G. J., & Bowman, D. M. J. S. (2019). Biomass consumption by surface fires across Earth's most fire prone continent. Global Change Biology, 25(1), 254-268. https://doi.org/10.1111/gcb.14460
    Murphy, Brett P. ; Prior, Lynda D. ; Cochrane, Mark A. ; Williamson, Grant J. ; Bowman, David M.J.S. / Biomass consumption by surface fires across Earth's most fire prone continent. In: Global Change Biology. 2019 ; Vol. 25, No. 1. pp. 254-268.
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    Murphy, BP, Prior, LD, Cochrane, MA, Williamson, GJ & Bowman, DMJS 2019, 'Biomass consumption by surface fires across Earth's most fire prone continent', Global Change Biology, vol. 25, no. 1, pp. 254-268. https://doi.org/10.1111/gcb.14460

    Biomass consumption by surface fires across Earth's most fire prone continent. / Murphy, Brett P.; Prior, Lynda D.; Cochrane, Mark A.; Williamson, Grant J.; Bowman, David M.J.S.

    In: Global Change Biology, Vol. 25, No. 1, 01.2019, p. 254-268.

    Research output: Contribution to journalArticleResearchpeer-review

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