A colleague is interested in the problem of mega-fires. If there are scientific papers for the United States, Australia or France, there is little research for South America. In France, a mega fire can be identified from 1,000 ha, in the United States or Australia from 10,000 ha.
Are there any studies in South America (e.g. Chile)?
Are there objective criteria for defining a mega fire?
Many thanks!
Hi,
I think it depends on the research question. Politically it is interesting how each country defines megafire. Ecologically, I would say it also depends in how common is fire as an ecological disturbance.
To the best of my knowledge, the Chilean Forest Service (a public-private entity) only defined "wildfires of magnitude" as those larger than 200 ha
More info here http://www.conaf.cl/incendios-forestales/incendios-forestales-en-chile/estadisticas-historicas/
I hope that helps!
Daniela
Hi Daniela,
Thank you for your answer!
You're right, it depends on the research question, and I'll let Lafitte Jérôme give some details.
This issue is quite complex in that there can be ecological disturbance below 200 ha, and setting a threshold at 200h ha is partly a political decision that would also need to be analysed.
The information on the CONAF website may provide further details.
Cheers,
Nicolas
https://doi.org/10.3390/resources7020026
https://doi.org/10.1071/WF19086
It will also depend on average forests size in each country, the natural existence of fires, as well as the use of fire for management (which will be also related to plot sizes). And even in a country it seems there is no one clear definition:
https://scholar.colorado.edu/concern/graduate_thesis_or_dissertations/5999n364d
No, there is no international standard for a megafire, and I actually recommend not using this term, which is more of a buzzword than anything scientifically defined.
I suggest reading the work by Fantina Tedim on extreme wildfire events and wildfire disasters, work that is much more applicable and sound.
Suggest having a look at this report: L Sullivan, A., Baker, E. and Kurvits, T., 2022. United Nations Environment Programme. Spreading Like Wildfire: The Rising Threat of Extraordinary Landscape Fires.
In this report is a Case study: Chilean production forests
For the purposes of the report, “wildfire” is defined as “an unusual or extraordinary free-burning vegetation fire which may be started maliciously, accidently, or through natural means, that negatively influences social, economic, or environmental values”.
Also see this reference which refers to a metafire regime in relation to spatial and temporal scales : On millennial timescales, slow variations in climate change, vegetation, and prehistoric burning practices alter ecosystem development and the nature of “metafire” regimes over broad scales (see Fig. 1). In Gillson, L., Whitlock, C. and Humphrey, G., 2019. Resilience and fire management in the Anthropocene. Ecology and Society, 24(3).
See this one Nicolas: Fire | Free Full-Text | Defining Extreme Wildfire Events: Difficulties, Challenges, and Impacts (mdpi.com)
Hi all,
You might be interested in this paper that just came up today in GEB:
Article What do you mean, ‘megafire’?
In summary, "we found 109 studies that define the term ‘megafire’ or identify a megafire, with the term first appearing in the peer-reviewed literature in 2005. Seventy-one (~65%) of these studies attempted to describe or define the term. There was considerable variability in the criteria used to define megafire, although definitions of megafire based on fire size were most common. Megafire size thresholds varied geographically from > 100–100,000 ha, with fires > 10,000 ha the most common size threshold (41%, 18/44 studies). Definitions of megafire were most common from studies led by authors from North America (52%, 37/71). We recorded 137 instances from 84 studies where fires were reported as megafires, the vast majority (94%, 129/137) of which exceed 10,000 ha in size. Megafires occurred in a range of biomes, but were most frequently described in forested biomes (112/137, 82%), and usually described single ignition fires (59% 81/137)".
cheers,
Interesting discussion. Clearly what can be considered a "mega" or "extreme" fire will depend on the studied ecosystem. You might be interested in this (open access) article about extreme wildfire years in northwestern Canada: https://www.tandfonline.com/doi/full/10.1080/11956860.2022.2070342
Nicolas Maestripieri The answer to your question is here:
https://onlinelibrary.wiley.com/doi/10.1111/geb.13499?fbclid=IwAR0NYahvbWjEVxar3jSxRdbjwKuTTrSuyVPu0wuWmWA_db3yxFOkOQT5Hmw
"definition of megafire as fires > 10,000 ha arising from single or multiple related ignition events. We introduce two additional terms – gigafire (> 100,000 ha) and terafire (> 1,000,000 ha) – for fires of an even larger scale than megafires."
In old sources (70-80s), it is said that fires that burn 500 hectares and large areas for Turkey are considered as large fires. Extreme fire definition did not exist at that time.
Paulo Fernandes I understand that the term is not scientifically acceptable and recognized (based on the answer of François-Nicolas Robinne . Therefore extreme wildfire is more appropriate? Thank you all for your answers!
Nicolas Maestripieri Depending on the context/purpose, a given term may be more or less adequate. If the focus is on size, then Extremely Large Fires may be an option (I have used it), but you should define it based on fire size distribution and possibly adopt a threshold percentile. If the focus is more on impact (and size and impact can be entirely decoupled) then I would go for Extreme Wildfire Events.
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