Editing Wildfire (section)

== Impacts on the natural environment ==

=== On the atmosphere ===
{{See also|Air pollution|Carbon cycle|Atmospheric chemistry|Haze|1997 Southeast Asian haze|2005 Malaysian haze}}
[[File:Western_fires_2020.jpg|Wildfire smoke in the [[atmosphere]] off the [[U.S. West Coast]] in 2020|thumb]]

Most of Earth's weather and air pollution resides in the [[troposphere]], the part of the atmosphere that extends from the surface of the planet to a height of about {{convert|10|km|mi|sigfig=1|sp=us}}. The vertical lift of a severe thunderstorm or [[pyrocumulonimbus]] can be enhanced in the area of a large wildfire, which can propel smoke, [[soot]] ([[black carbon]]), and other [[Atmospheric particulate matter|particulate matter]] as high as the lower [[stratosphere]].<ref>{{cite conference |last=Wang |first=P.K. |date=2003 |title=The physical mechanism of injecting biomass burning materials into the stratosphere during fire-induced thunderstorms |location=San Francisco |publisher=American Geophysical Union fall meeting}}</ref> Previously, prevailing scientific theory held that most particles in the stratosphere came from [[volcano]]es, but smoke and other wildfire emissions have been detected from the lower stratosphere.<ref>{{cite conference |author=Fromm, M. |author2=Stocks, B. |author3=Servranckx, R. |author4=Lindsey, D. |title=Smoke in the Stratosphere: What Wildfires have Taught Us About Nuclear Winter; abstract #U14A-04 |bibcode=2006AGUFM.U14A..04F |conference=American Geophysical Union, Fall Meeting 2006}}</ref> Pyrocumulus clouds can reach {{convert|6100|m|ft|sp=us}} over wildfires.<ref>Graham, ''et al''., 17</ref> Satellite observation of smoke plumes from wildfires revealed that the plumes could be traced intact for distances exceeding {{convert|1600|km|mi|sigfig=1|sp=us}}.<ref>{{cite web |author=John R. Scala |display-authors=etal |title=Meteorological Conditions Associated with the Rapid Transport of Canadian Wildfire Products into the Northeast during 5–8 July 2002 |url=http://ams.confex.com/ams/pdfpapers/68737.pdf |archive-url=https://web.archive.org/web/20090226080555/http://ams.confex.com/ams/pdfpapers/68737.pdf |archive-date=26 February 2009 |access-date=4 February 2009 |publisher=American Meteorological Society }}</ref> Computer-aided models such as [[CALPUFF]] may help predict the size and direction of wildfire-generated smoke plumes by using [[atmospheric dispersion modeling]].<ref>{{cite web |last1=Breyfogle |first1=Steve |last2=Sue A. |first2=Ferguson |date=December 1996 |title=User Assessment of Smoke-Dispersion Models for Wildland Biomass Burning |url=http://www.fs.fed.us/pnw/pubs/pnw_gtr379.pdf |url-status=live |archive-url=https://web.archive.org/web/20090226080555/http://www.fs.fed.us/pnw/pubs/pnw_gtr379.pdf |archive-date=26 February 2009 |access-date=6 February 2009 |publisher=US Forest Service }}</ref>

Wildfires can affect local atmospheric pollution,<ref>{{cite journal |last=Bravo |first=A.H. |author2=E.R. Sosa |author3=A.P. Sánchez |author4=P.M. Jaimes |author5=R.M.I. Saavedra |name-list-style=amp |date=2002 |title=Impact of wildfires on the air quality of Mexico City, 1992–1999 |journal=Environmental Pollution |volume=117 |issue=2 |pages=243–253 |doi=10.1016/S0269-7491(01)00277-9 |pmid=11924549}}</ref> and release carbon in the form of carbon dioxide.<ref>{{Cite journal |last1=Dore |first1=S. |last2=Kolb |first2=T.E. |last3=Montes-Helu |first3=M. |last4=Eckert |first4=S.E. |last5=Sullivan |first5=B.W. |last6=Hungate |first6=B.A. |last7=Kaye |first7=J.P. |last8=Hart |first8=S.C. |last9=Koch |first9=G.W. |date=1 April 2010 |title=Carbon and water fluxes from ponderosa pine forests disturbed by wildfire and thinning |journal=Ecological Applications |language=en |volume=20 |issue=3 |pages=663–683 |doi=10.1890/09-0934.1 |issn=1939-5582 |pmid=20437955|bibcode=2010EcoAp..20..663D }}</ref> [[Wildland fire emissions|Wildfire emissions]] contain fine particulate matter which can cause cardiovascular and respiratory problems.<ref>{{cite web |last=Douglass |first=R. |date=2008 |title=Quantification of the health impacts associated with fine particulate matter due to wildfires. MS Thesis |url=http://dukespace.lib.duke.edu/dspace/bitstream/10161/495/1/MP_rld10_a_052008.pdf |archive-url=https://web.archive.org/web/20100610213236/http://dukespace.lib.duke.edu/dspace/bitstream/10161/495/1/MP_rld10_a_052008.pdf |archive-date=10 June 2010 |access-date=1 April 2010 |publisher=Nicholas School of the Environment and Earth Sciences of Duke University }}</ref> Increased fire byproducts in the troposphere can increase ozone concentrations beyond safe levels.<ref>{{cite web |author=National Center for Atmospheric Research |date=13 October 2008 |title=Wildfires Cause Ozone Pollution to Violate Health Standards |url=http://www.innovations-report.de/html/berichte/geowissenschaften/wildfires_ozone_pollution_violate_health_standards_120086.html |archive-url=https://web.archive.org/web/20110927124441/http://www.innovations-report.de/html/berichte/geowissenschaften/wildfires_ozone_pollution_violate_health_standards_120086.html |archive-date=27 September 2011 |access-date=4 February 2009 |publisher=Geophysical Research Letters }}</ref>

=== On ecosystems ===
{{Main|Fire ecology}}

{{See also|Disturbance (ecology)|Forestry}}Wildfires are common in climates that are sufficiently moist to allow the growth of vegetation but feature extended dry, hot periods.<ref name="NOVA222"/> Such places include the vegetated areas of Australia and [[Southeast Asia]], the [[veld]] in southern Africa, the [[fynbos]] in the Western Cape of [[South Africa]], the forested areas of the United States and Canada, and the [[Mediterranean Basin]].

High-severity wildfire creates [[complex early seral forest]] habitat (also called "snag forest habitat"), which often has higher species richness and diversity than unburned old forest.<ref name=":1">{{cite book |doi=10.1016/B978-0-12-802749-3.00011-6 |chapter=In the Aftermath of Fire |title=The Ecological Importance of Mixed-Severity Fires |date=2015 |last1=Dellasala |first1=Dominick A. |last2=Lindenmayer |first2=David B. |last3=Hanson |first3=Chad T. |last4=Furnish |first4=Jim |pages=313–347 |isbn=978-0-12-802749-3 }}</ref> Plant and animal species in most types of North American forests evolved with fire, and many of these species depend on wildfires, and particularly high-severity fires, to reproduce and grow. Fire helps to return nutrients from plant matter back to the soil. The heat from fire is necessary to the germination of certain types of seeds, and the snags (dead trees) and early successional forests created by high-severity fire create habitat conditions that are beneficial to wildlife.<ref name=":1" /> Early successional forests created by high-severity fire support some of the highest levels of native biodiversity found in temperate conifer forests.<ref name=":2">{{Cite journal |last=Hutto |first=Richard L. |date=1 December 2008 |title=The Ecological Importance of Severe Wildfires: Some Like It Hot |url=https://scholarworks.umt.edu/biosci_pubs/279 |journal=Ecological Applications |language=en |volume=18 |issue=8 |pages=1827–1834 |doi=10.1890/08-0895.1 |issn=1939-5582 |pmid=19263880 |doi-access=free |bibcode=2008EcoAp..18.1827H |access-date=27 August 2019 |archive-date=9 July 2023 |archive-url=https://web.archive.org/web/20230709174631/https://scholarworks.umt.edu/biosci_pubs/279/ |url-status=live }}<!--https://scholarworks.umt.edu/cgi/viewcontent.cgi?article=1280&context=biosci_pubs--></ref><ref>{{Cite journal |last1=Donato |first1=Daniel C. |last2=Fontaine |first2=Joseph B. |last3=Robinson |first3=W. Douglas |last4=Kauffman |first4=J. Boone |last5=Law |first5=Beverly E. |date=1 January 2009 |title=Vegetation response to a short interval between high-severity wildfires in a mixed-evergreen forest |url=https://researchrepository.murdoch.edu.au/id/eprint/2578/ |journal=Journal of Ecology |language=en |volume=97 |issue=1 |pages=142–154 |doi=10.1111/j.1365-2745.2008.01456.x |issn=1365-2745 |doi-access=free |bibcode=2009JEcol..97..142D |access-date=3 December 2019 |archive-date=30 March 2023 |archive-url=https://web.archive.org/web/20230330084911/https://researchrepository.murdoch.edu.au/id/eprint/2578/ |url-status=live }}</ref> Post-fire logging has no ecological benefits and many negative impacts; the same is often true for post-fire seeding.<ref name=":5" /> The exclusion of wildfires can contribute to vegetation regime shifts, such as [[woody plant encroachment]].<ref>{{Cite journal |last1=O'Connor |first1=Tim G. |last2=Puttick |first2=James R. |last3=Hoffman |first3=M. Timm |date=4 May 2014 |title=Bush encroachment in southern Africa: changes and causes |journal=African Journal of Range & Forage Science |volume=31 |issue=2 |pages=67–88 |doi=10.2989/10220119.2014.939996 |bibcode=2014AJRFS..31...67O }}</ref><ref>{{Cite journal |last1=Cardoso |first1=Anabelle W. |last2=Archibald |first2=Sally |last3=Bond |first3=William J. |last4=Coetsee |first4=Corli |last5=Forrest |first5=Matthew |last6=Govender |first6=Navashni |last7=Lehmann |first7=David |last8=Makaga |first8=Loïc |last9=Mpanza |first9=Nokukhanya |last10=Ndong |first10=Josué Edzang |last11=Koumba Pambo |first11=Aurélie Flore |last12=Strydom |first12=Tercia |last13=Tilman |first13=David |last14=Wragg |first14=Peter D. |last15=Staver |first15=A. Carla |date=28 June 2022 |title=Quantifying the environmental limits to fire spread in grassy ecosystems |journal=Proceedings of the National Academy of Sciences |volume=119 |issue=26 |pages=e2110364119 |doi=10.1073/pnas.2110364119 |doi-access=free |pmc=9245651 |pmid=35733267 |bibcode=2022PNAS..11910364C }}</ref>

Although some ecosystems rely on naturally occurring fires to regulate growth, some ecosystems suffer from too much fire, such as the [[chaparral]] in [[southern California]] and lower-elevation deserts in the American Southwest. The increased fire frequency in these ordinarily fire-dependent areas has upset natural cycles, damaged native plant communities, and encouraged the growth of non-native weeds.<ref>''Interagency Strategy for the Implementation of the Federal Wildland Fire Policy'', 3, 37.</ref><ref>Graham, ''et al''., 3.</ref><ref>{{cite journal |author=Keeley, J.E. |date=1995 |title=Future of California floristics and systematics: wildfire threats to the California flora |url=http://www.werc.usgs.gov/seki/pdfs/Future%20of%20California%20Floristics%20and%20Systematics%20Wildfire%20Th.pdf |url-status=live |journal=Madroño |volume=42 |pages=175–179 |archive-url=https://web.archive.org/web/20090507033351/http://www.werc.usgs.gov/seki/pdfs/Future%20of%20California%20Floristics%20and%20Systematics%20Wildfire%20Th.pdf |archive-date=7 May 2009 |access-date=26 June 2009 }}</ref><ref>{{cite conference |last=Zedler |first=P.H. |date=1995 |editor2=Scott, T. |title=Fire frequency in southern California shrublands: biological effects and management options |publisher=International Association of Wildland Fire |pages=101–112 |book-title=Brushfires in California wildlands: ecology and resource management |editor=Keeley, J.E. |place=Fairfield, WA}}</ref> [[Invasive species]], such as ''[[Lygodium microphyllum]]'' and ''[[Bromus tectorum]]'', can grow rapidly in areas that were damaged by fires. Because they are highly flammable, they can increase the future risk of fire, creating a [[positive feedback loop]] that increases fire frequency and further alters native vegetation communities.<ref name="FireInitiative" /><ref name="van Wagtendonk, 14" />

In the [[Amazon rainforest]], drought, logging, cattle ranching practices, and [[slash-and-burn]] agriculture damage fire-resistant forests and promote the growth of flammable brush, creating a cycle that encourages more burning.<ref>Nepstad, 4, 8–11</ref> Fires in the rainforest threaten its collection of diverse species and produce large amounts of CO<sub>2</sub>.<ref>{{cite web |last=Lindsey |first=Rebecca |date=5 March 2008 |title=Amazon fires on the rise |url=http://earthobservatory.nasa.gov/Features/AmazonFireRise/ |url-status=live |archive-url=https://web.archive.org/web/20090813154232/http://earthobservatory.nasa.gov/Features/AmazonFireRise/ |archive-date=13 August 2009 |access-date=9 July 2009 |publisher=Earth Observatory (NASA)}}</ref> Also, fires in the rainforest, along with drought and human involvement, could damage or destroy more than half of the Amazon rainforest by 2030.<ref>Nepstad, 4</ref> Wildfires generate ash, reduce the availability of organic nutrients, and cause an increase in water runoff, eroding other nutrients and creating [[flash flood]] conditions.<ref name="Graham, et al., iv" /><ref>{{cite web |title=Bushfire and Catchments: Effects of Fire on Soils and Erosion |url=http://www.ewatercrc.com.au/bushfire/background_effects.shtml |archive-url=https://web.archive.org/web/20070830055708/http://www.ewatercrc.com.au/bushfire/background_effects.shtml |archive-date=30 August 2007 |access-date=8 January 2009 |url-status=usurped |publisher=eWater Cooperative Research Center's}}</ref> A 2003 wildfire in the [[North Yorkshire Moors]] burned off {{convert|2.5|km2|acre|sigfig=1|sp=us}} of [[Ericaceae|heather]] and the underlying [[peat]] layers. Afterwards, wind erosion stripped the ash and the exposed soil, revealing archaeological remains dating to 10,000&nbsp;BC.<ref>{{cite journal |last=Refern |first=Neil |author2=Vyner, Blaise |title=Fylingdales Moor a lost landscape rises from the ashes |journal=Current Archaeology |volume=XIX |issue=226 |pages=20–27 |issn=0011-3212}}</ref> Wildfires can also have an effect on climate change, increasing the amount of carbon released into the atmosphere and inhibiting vegetation growth, which affects overall carbon uptake by plants.<ref>{{cite journal |last=Running |first=S.W. |date=2008 |title=Ecosystem Disturbance, Carbon and Climate |journal=Science |volume=321 |issue=5889 |pages=652–653 |doi=10.1126/science.1159607 |pmid=18669853 |s2cid=206513681}}</ref>

=== On waterways ===

Debris and chemical runoff into waterways after wildfires can make drinking water sources unsafe.<ref>{{Cite journal |last1=Proctor |first1=Caitlin R. |last2=Lee |first2=Juneseok |last3=Yu |first3=David |last4=Shah |first4=Amisha D. |last5=Whelton |first5=Andrew J. |year=2020 |title=Wildfire caused widespread drinking water distribution network contamination |journal=AWWA Water Science |volume=2 |issue=4 |doi=10.1002/aws2.1183 |bibcode=2020AWWWS...2E1183P |s2cid=225641536}}</ref> Though it is challenging to quantify the impacts of wildfires on surface water quality, research suggests that the concentration of many pollutants increases post-fire. The impacts occur during active burning and up to years later.<ref>{{Cite web |title=Wildfires and Water Quality {{!}} U.S. Geological Survey |url=https://www.usgs.gov/centers/california-water-science-center/science/science-topics/wildfires-and-water-quality#:~:text=Wildfires%20can%20compromise%20water%20quality,and%20drinking-water%20treatment%20processes. |access-date=26 October 2023 |website=www.usgs.gov |archive-date=26 October 2023 |archive-url=https://web.archive.org/web/20231026140951/https://www.usgs.gov/centers/california-water-science-center/science/science-topics/wildfires-and-water-quality#:~:text=Wildfires%20can%20compromise%20water%20quality,and%20drinking-water%20treatment%20processes. |url-status=live }}</ref> Increases in nutrients and total suspended sediments can happen within a year while heavy metal concentrations may peak 1–2 years after a wildfire.<ref>{{Cite journal |last1=Raoelison |first1=Onja D. |last2=Valenca |first2=Renan |last3=Lee |first3=Allison |last4=Karim |first4=Samiha |last5=Webster |first5=Jackson P. |last6=Poulin |first6=Brett A. |last7=Mohanty |first7=Sanjay K. |date=15 January 2023 |title=Wildfire impacts on surface water quality parameters: Cause of data variability and reporting needs |journal=Environmental Pollution |volume=317 |page=120713 |doi=10.1016/j.envpol.2022.120713 |pmid=36435284 |bibcode=2023EPoll.31720713R }}</ref>

Benzene is one of many chemicals that have been found in drinking water systems after wildfires. Benzene can permeate certain plastic pipes and thus require long times to be removed from the water distribution infrastructure. Researchers estimated that, in worst case scenarios, more than 286 days of constant flushing of a contaminated HDPE service line were needed to reduce benzene below safe drinking water limits.<ref>{{Cite web |date=18 March 2019 |title=Considerations for Decontaminating HDPE Service Lines by Flushing |url=https://engineering.purdue.edu/PlumbingSafety/opinions/Final-HDPE-Service-Line-Decontamination-2019-03-18.pdf |website=engineering.purdue.edu |access-date=14 July 2021 |archive-date=13 August 2023 |archive-url=https://web.archive.org/web/20230813140928/https://engineering.purdue.edu/PlumbingSafety/opinions/Final-HDPE-Service-Line-Decontamination-2019-03-18.pdf |url-status=live }}</ref><ref>{{Cite journal |last1=Haupert |first1=Levi M. |last2=Magnuson |first2=Matthew L. |year=2019 |title=Numerical Model for Decontamination of Organic Contaminants in Polyethylene Drinking Water Pipes in Premise Plumbing by Flushing |journal=Journal of Environmental Engineering |volume=145 |issue=7 |doi=10.1061/(ASCE)EE.1943-7870.0001542 |pmc=7424390 |pmid=32801447}}</ref> Temperature increases caused by fires, including wildfires, can cause plastic water pipes to generate toxic chemicals<ref>{{Cite journal |last1=Isaacson |first1=Kristofer P. |last2=Proctor |first2=Caitlin R. |last3=Wang |first3=Q. Erica |last4=Edwards |first4=Ethan Y. |last5=Noh |first5=Yoorae |last6=Shah |first6=Amisha D. |last7=Whelton |first7=Andrew J. |year=2021 |title=Drinking water contamination from the thermal degradation of plastics: Implications for wildfire and structure fire response |journal=Environmental Science: Water Research & Technology |volume=7 |issue=2 |pages=274–284 |doi=10.1039/D0EW00836B |s2cid=230567682 |doi-access=free}}</ref> such as [[benzene]].<ref>{{Cite web |last= |first= |date=28 December 2020 |title=Plastic pipes are polluting drinking water systems after wildfires |url=https://arstechnica.com/science/2020/12/plastic-pipes-are-polluting-drinking-water-systems-after-wildfires/ |access-date=10 January 2021 |website=[[Ars Technica]] |archive-date=26 May 2023 |archive-url=https://web.archive.org/web/20230526210836/https://arstechnica.com/science/2020/12/plastic-pipes-are-polluting-drinking-water-systems-after-wildfires/ |url-status=live }}</ref>

=== On plant and animals ===
[[File:Boreal pine forest after fire.JPG|thumb|upright=2|alt=Two photographs of the same section of a pine forest; both show blackened bark at least halfway up the trees. The first picture is noticeably lacking in surface vegetation, while the second shows small, green grasses on the forest floor.|[[Ecological succession]] after a wildfire in a [[boreal forest|boreal pine forest]] next to Hara Bog, [[Lahemaa National Park]], [[Estonia]]. The pictures were taken one and two years after the fire.]]
{{excerpt|Fire adaptations|file=no}}

{{wide image|Fire activity swifts creek 2007 edit.jpg|933px|Smoke trail from a fire seen while looking towards [[Dargo, Victoria|Dargo]] from [[Swifts Creek, Victoria|Swifts Creek]], Victoria, Australia, 11 January 2007|alt=Panorama of a hilly expanse featuring a large smoke trail covering more than half of the visible sky.}}