Wildfire

Wildfire burning in the Kaibab National Forest, Arizona, United States, in 2020. The Mangum Fire burned more than 70,000 acres (280 km2) of forest.
Wildfire near Yosemite National Park, United States, in 2013. The Rim Fire burned more than 250,000 acres (1,000 km2) of forest.

A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation.[1][2] Depending on the type of vegetation present, a wildfire may be more specifically identified as a bushfire (in Australia), desert fire, grass fire, hill fire, peat fire, prairie fire, vegetation fire, or veld fire.[3] Some natural forest ecosystems depend on wildfire.[4] Wildfires are distinct from beneficial human usage of wildland fire, called controlled or prescribed burning, although controlled burns can turn into wildfires. Modern forest management often engages in prescribed burns to mitigate risk and promote natural forest cycles.

Wildfires are often classified by characteristics like cause of ignition, physical properties, combustible material present, and the effect of weather on the fire.[5] Wildfire behavior and severity result from a combination of factors such as available fuels, physical setting, and weather.[6][7][8][9] Climatic cycles with wet periods that create substantial fuels, followed by drought and heat, often proceed severe wildfires.[10] These cycles have been intensified by climate change.[11]

Naturally occurring wildfires have beneficial effects on native vegetation, animals, and ecosystems that have evolved with fire.[12][13][14] Many plant species depend on the effects of fire for growth and reproduction.[15] Some natural forests are dependent on wildfire.[16] High-severity wildfires may create complex early seral forest habitat (also called "snag forest habitat"), which may have higher species richness and diversity than an unburned old forest.

Human societies can be severely impacted by fires. Effects include the direct health impacts of smoke and fire, destruction of property (especially in wildland–urban interfaces) economic and ecosystem services losses, and contamination of water and soil.[11]

Wildfires are among the most common forms of natural disaster in some regions, including Siberia, California, British Columbia, and Australia.[17][18][19][20] Areas with Mediterranean climates or in the taiga biome are particularly susceptible. At a global level, human practices have made the impacts of wildfire worse, with a doubling in land area burned by wildfires compared to natural levels.[11] Humans have impacted wildfire through climate change, land-use change, and wildfire suppression.[11] The increase in severity of fires in the US creates a positive feedback loop by releasing naturally sequestered carbon back into the atmosphere, increasing the atmosphere's greenhouse effect thereby contributing to climate change.[11]

  1. ^ Cambridge Advanced Learner's Dictionary (Third ed.). Cambridge University Press. 2008. ISBN 978-0-521-85804-5. Archived from the original on 13 August 2009.
  2. ^ "CIFFC Canadian Wildland Fire Management Glossary" (PDF). Canadian Interagency Forest Fire Centre. Retrieved 16 August 2019.
  3. ^ "Forest fire videos – See how fire started on Earth". BBC Earth. Archived from the original on 16 October 2015. Retrieved 13 February 2016.
  4. ^ "Drought, Tree Mortality, and Wildfire in Forests Adapted to Frequent Fire" (PDF). UC Berkeley College of Natural Resources. Retrieved 15 March 2022.
  5. ^ Flannigan, M.D.; B.D. Amiro; K.A. Logan; B.J. Stocks & B.M. Wotton (2005). "Forest Fires and Climate Change in the 21st century" (PDF). Mitigation and Adaptation Strategies for Global Change. 11 (4): 847–859. doi:10.1007/s11027-005-9020-7. S2CID 2757472. Archived from the original (PDF) on 25 March 2009. Retrieved 26 June 2009.
  6. ^ Graham, et al., 12, 36
  7. ^ National Wildfire Coordinating Group Communicator's Guide For Wildland Fire Management, 4–6.
  8. ^ "National Wildfire Coordinating Group Fireline Handbook, Appendix B: Fire Behavior" (PDF). National Wildfire Coordinating Group. April 2006. Archived (PDF) from the original on 17 December 2008. Retrieved 11 December 2008.
  9. ^ Trigo, Ricardo M.; Provenzale, Antonello; Llasat, Maria Carmen; AghaKouchak, Amir; Hardenberg, Jost von; Turco, Marco (6 March 2017). "On the key role of droughts in the dynamics of summer fires in Mediterranean Europe". Scientific Reports. 7 (1): 81. Bibcode:2017NatSR...7...81T. doi:10.1038/s41598-017-00116-9. ISSN 2045-2322. PMC 5427854. PMID 28250442.
  10. ^ Westerling, A. L.; Hidalgo, H. G.; Cayan, D. R.; Swetnam, T. W. (18 August 2006). "Warming and Earlier Spring Increase Western U.S. Forest Wildfire Activity". Science. 313 (5789): 940–943. Bibcode:2006Sci...313..940W. doi:10.1126/science.1128834. ISSN 0036-8075. PMID 16825536.
  11. ^ a b c d e Parmesan, Camille; Morecroft, Mike; Trisurat, Yongyut; et al. "Chapter 2: Terrestrial and Freshwater Ecosystems and their Services". Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Intergovernmental Panel on Climate Change.
  12. ^ Heidari, Hadi; Arabi, Mazdak; Warziniack, Travis (August 2021). "Effects of Climate Change on Natural-Caused Fire Activity in Western U.S. National Forests". Atmosphere. 12 (8): 981. Bibcode:2021Atmos..12..981H. doi:10.3390/atmos12080981.
  13. ^ DellaSalla, Dominick A.; Hanson, Chad T. (2015). The Ecological Importance of Mixed-Severity Fires. Elsevier. ISBN 978-0-12-802749-3.
  14. ^ Hutto, Richard L. (1 December 2008). "The Ecological Importance of Severe Wildfires: Some Like It Hot". Ecological Applications. 18 (8): 1827–1834. Bibcode:2008EcoAp..18.1827H. doi:10.1890/08-0895.1. ISSN 1939-5582. PMID 19263880.
  15. ^ Stephen J. Pyne. "How Plants Use Fire (And Are Used By It)". NOVA online. Archived from the original on 8 August 2009. Retrieved 30 June 2009.
  16. ^ "Drought, Tree Mortality, and Wildfire in Forests Adapted to Frequent Fire" (PDF). UC Berkeley College of Natural Resources. Retrieved 15 March 2022.
  17. ^ "Main Types of Disasters and Associated Trends". lao.ca.gov. Legislative Analyst's Office. 10 January 2019.
  18. ^ Machemer, Theresa (9 July 2020). "The Far-Reaching Consequences of Siberia's Climate-Change-Driven Wildfires". Smithsonian Magazine.
  19. ^ Australia, Government Geoscience (25 July 2017). "Bushfire". www.ga.gov.au.
  20. ^ "B.C. wildfires: State of emergency declared in Kelowna, evacuations underway | Globalnews.ca". Global News. Retrieved 18 August 2023.