A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustiblevegetation.[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]
^ abcdeParmesan, 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.