Editing Wildfire (section)

== Spread ==
{{See also|Surface-area-to-volume ratio#Fire spread}}
[[File:Wildfire near Cedar Fort, Utah.jpg|thumb|alt=Flat expanse of brown grasses and some green trees with black and some gray smoke and visible flames in the distance.|A surface fire in the western desert of [[Utah]], United States]]
[[File:Forest fire aftermath.jpg|thumb|alt=Mountainous region with blackened soil and trees due to a recent fire.|Charred landscape following a crown fire in the [[Cascade Range|North Cascades]], United States]]
[[File:Priske 24.03.2019.jpg|thumb|Forest fires visible from a distance in [[Dajti National Park]], [[Tirana]], Albania]]

The spread of wildfires varies based on the flammable material present, its vertical arrangement and moisture content, and weather conditions.<ref name="Graham, et al., iv">Graham, ''et al''., iv.</ref> Fuel arrangement and density is governed in part by [[topography]], as land shape determines factors such as available sunlight and water for plant growth. Overall, fire types can be generally characterized by their fuels as follows:
* '''Ground''' fires are fed by subterranean roots, duff on the [[forest floor]], and other buried [[organic  matter]].  Ground fires typically burn by smoldering, and can burn slowly for days to months, such as [[Peat#Peat Fires|peat fires]] in [[Kalimantan]] and Eastern [[Sumatra]], [[Indonesia]], which resulted from a [[Mega Rice Project (Kalimantan)|riceland creation project]] that unintentionally drained and dried the peat.<ref>Graham, ''et al''., 9, 13</ref><ref>{{cite news | url = http://news.bbc.co.uk/2/hi/science/nature/4208564.stm | title = Asian peat fires add to warming | publisher = British Broadcasting Corporation (BBC) News | last = Rincon | first = Paul | date = 9 March 2005 | access-date = 9 December 2008 | url-status = live | archive-url = https://web.archive.org/web/20081219064000/http://news.bbc.co.uk/2/hi/science/nature/4208564.stm | archive-date = 19 December 2008 }}</ref><ref>{{Cite web|url=https://www.sciencenews.org/article/bogs-peatlands-fire-climate-change|title=When bogs burn, the environment takes a hit|last=Hamers|first=Laurel|date=29 July 2019|website=Science News|language=en|access-date=15 August 2019|archive-date=3 January 2020|archive-url=https://web.archive.org/web/20200103151902/https://www.sciencenews.org/article/bogs-peatlands-fire-climate-change|url-status=live}}</ref>
* '''Crawling''' or '''surface''' fires are fueled by low-lying vegetative matter on the forest floor such as leaf and timber litter, debris, grass, and low-lying shrubbery.<ref>Graham, ''et al'' ., iv, 10, 14</ref> This kind of fire often burns at a relatively lower temperature than crown fires (less than {{convert|400|C|F|sigfig=2|disp=or}}) and may spread at slow rate, though steep slopes and wind can accelerate the rate of spread.<ref>{{Cite book|title=Fire on earth: an introduction |author=Andrew C. Scott |author2=David M. J. S. Bowman |author3=William J. Bond |author4=Stephen J. Pyne |author5=Martin E. Alexander |isbn=978-1-119-95357-9|location=Chichester, West Sussex |publisher=Wiley |oclc=854761793|year=2014}}</ref> This fuel type is especially susceptible to ignition due to ''spotting'' {{See below|[[#Spotting|below]]}}.
* '''Ladder''' fires consume material between low-level vegetation and tree canopies, such as small trees, downed logs, and [[vine]]s. [[Kudzu]], [[Old World climbing fern]], and other [[invasive plant]]s that scale trees may also encourage ladder fires.<ref name="FireInitiative">{{cite web | url = http://www.tncfire.org/crosscutting_fandi.htm | title = Global Fire Initiative: Fire and Invasives | publisher = The Nature Conservancy | access-date = 3 December 2008 | archive-url = https://web.archive.org/web/20090412054533/http://www.tncfire.org/crosscutting_fandi.htm | archive-date = 12 April 2009 }}</ref>
* '''Crown, canopy''', or '''aerial''' fires burn suspended material at the canopy level, such as tall trees, vines, and mosses. The ignition of a crown fire, termed ''crowning'', is dependent on the density of the suspended material, canopy height, canopy continuity, sufficient surface and ladder fires, vegetation moisture content, and weather conditions during the blaze.<ref>Graham, ''et al''., iv, 8, 11, 15.</ref> Stand-replacing fires lit by humans can spread into the [[Amazon rain forest]], damaging ecosystems not particularly suited for heat or arid conditions.<ref>{{cite web|url=http://e360.yale.edu/content/feature.msp?id=2010|title=Global Commodities Boom Fuels New Assault on Amazon|last=Butler|first=Rhett|publisher=Yale School of Forestry & Environmental Studies|access-date=9 July 2009|date=19 June 2008|archive-url=https://web.archive.org/web/20090411124535/http://e360.yale.edu/content/feature.msp?id=2010|archive-date=11 April 2009}}</ref>