FLARE Wildfire Research, School of Ecosystem and Forest Sciences, The University of Melbourne, Parkville, Victoria, Australia.
Centre for Environmental Risk Management of Bushfires, Centre for Sustainable Ecosystem Solutions, University of Wollongong, Wollongong, New South Wales, Australia.
Glob Chang Biol. 2022 Sep;28(17):5211-5226. doi: 10.1111/gcb.16283. Epub 2022 Jun 16.
Fire regimes are changing across the globe in response to complex interactions between climate, fuel, and fire across space and time. Despite these complex interactions, research into predicting fire regime change is often unidimensional, typically focusing on direct relationships between fire activity and climate, increasing the chances of erroneous fire predictions that have ignored feedbacks with, for example, fuel loads and availability. Here, we quantify the direct and indirect role of climate on fire regime change in eucalypt dominated landscapes using a novel simulation approach that uses a landscape fire modelling framework to simulate fire regimes over decades to centuries. We estimated the relative roles of climate-mediated changes as both direct effects on fire weather and indirect effects on fuel load and structure in a full factorial simulation experiment (present and future weather, present and future fuel) that included six climate ensemble members. We applied this simulation framework to predict changes in fire regimes across six temperate forested landscapes in south-eastern Australia that encompass a broad continuum from climate-limited to fuel-limited. Climate-mediated change in weather and fuel was predicted to intensify fire regimes in all six landscapes by increasing wildfire extent and intensity and decreasing fire interval, potentially led by an earlier start to the fire season. Future weather was the dominant factor influencing changes in all the tested fire regime attributes: area burnt, area burnt at high intensity, fire interval, high-intensity fire interval, and season midpoint. However, effects of future fuel acted synergistically or antagonistically with future weather depending on the landscape and the fire regime attribute. Our results suggest that fire regimes are likely to shift across temperate ecosystems in south-eastern Australia in coming decades, particularly in climate-limited systems where there is the potential for a greater availability of fuels to burn through increased aridity.
全球范围内的火灾发生情况正在发生变化，这是气候、燃料和火灾在空间和时间上的复杂相互作用的结果。尽管存在这些复杂的相互作用，但预测火灾发生情况变化的研究往往是单一维度的，通常侧重于火灾活动与气候之间的直接关系，增加了错误预测火灾的可能性，而这些错误预测忽略了与燃料负荷和可获得性等因素的反馈。在这里，我们使用一种新颖的模拟方法来量化气候对桉树为主的景观中火发生情况变化的直接和间接作用，该方法使用景观火灾模拟框架来模拟几十年到几个世纪的火灾发生情况。我们估计了气候介导的变化的相对作用，这些变化既是对火天气的直接影响，也是对燃料负荷和结构的间接影响，这是在一个包含六个气候集合成员的全因子模拟实验（现在和未来的天气、现在和未来的燃料）中进行的。我们应用这种模拟框架来预测澳大利亚东南部六个温带森林景观中火发生情况的变化，这些景观涵盖了从气候限制到燃料限制的广泛范围。气候介导的天气和燃料变化预计将通过增加野火的范围和强度，减少火灾间隔，从而加剧所有六个景观中的火灾发生情况，这可能是由于火灾季节提前开始导致的。未来的天气是影响所有测试的火灾发生情况属性变化的主要因素：燃烧面积、高强度燃烧面积、火灾间隔、高强度火灾间隔和季节中点。然而，未来燃料的影响取决于景观和火灾发生情况属性，与未来天气协同或拮抗。我们的研究结果表明，在未来几十年，澳大利亚东南部的温带生态系统中的火灾发生情况可能会发生变化，特别是在气候限制系统中，由于干旱程度增加，燃料的可用性可能会增加，从而有可能燃烧更多的燃料。
