Editing Pinus contorta (section)

== Ecology ==
''Pinus contorta'' is a [[Fire ecology|fire-dependent species]], requiring [[wildfire]]s to maintain healthy populations of diverse ages. The thin bark of the lodgepole pine minimizes its defense to fire, although the heat of fire opens the cones to release the seeds. This allows the species to regenerate and maintain its place in the forest habitat.<ref name="Schoennagel" /> It otherwise fares poorly in crowds as other species are more [[shade tolerant]], although some (e.g. [[fir]]s) are more susceptible to fire.<ref name=":0">{{Cite book|last1=Arno|first1=Stephen F.|url=https://books.google.com/books?id=qDD4DwAAQBAJ|title=Northwest Trees: Identifying & Understanding the Region's Native Trees|last2=Hammerly|first2=Ramona P.|publisher=[[Mountaineers Books]]|year=2020|isbn=978-1-68051-329-5|edition=field guide|location=Seattle|pages=61–70|language=en|oclc=1141235469|orig-date=1977}}</ref>
{{multiple image
| align             = right
| direction         = vertical
| width             = 200
| image1            = Lodgepole pine forest 1965.jpg
| image2            = Lodgepole pine Yellowstone 1998 near firehole.jpg
| caption2          = ''P. contorta'' subsp. ''latifolia'' forest 23 years before (above) and 10 years after (below) the [[Yellowstone fires of 1988]]
}}

The natural fire regime for this species is primarily driven by climate. The fires occur most often after years of drought. Forests in the upper montane to subalpine region experience much moisture in the winter via snow. The density of [[tree stand]]s with the species inhibit the establishment of an understory (allowing [[ladder fuel]] to form), and surface fire is rare regardless. Thus, infrequent but severe fires dominate this species.<ref name="Schoennagel">{{cite journal|author1-link=Tania Schoennagel|last=Schoennagel|first=Tania|author2=Thomas Veblen |title=The Interaction of Fire, Fuels and Climate across Rocky Mountain Forests|journal=BioScience|volume=54|issue=7|year=2004|pages=661–76|doi=10.1641/0006-3568(2004)054[0661:TIOFFA]2.0.CO;2|issn=0006-3568|doi-access=free}}</ref>

An example of the climate that plays a huge role in the fire regime of the species is quite complex. There are three different oscillations that play a major role in droughts. These are the [[Pacific decadal oscillation]] (PDO), [[Atlantic multidecadal oscillation]] (AMO) and [[El Niño]] (ENSO). A combination of these oscillations being in effect (+) or not in effect (−) have a global effect on the water available to these forests. The combination of AMO +, ENSO − and PDO − means there is going to be a drought and likely a severe subalpine fire.<ref>{{cite journal|last=Kauffman|first=J. Boone|title=Death Rides the Forest: Perceptions of Fire, Land Use and Ecological Restoration of Western Forests|journal=Conservation Biology|volume=18|issue=4|date=August 2004|pages=878–82|access-date=24 February 2010|url=http://eebweb.arizona.edu/courses/Ecol406R_506R/Kauffman2004ConBio.pdf|doi=10.1111/j.1523-1739.2004.545_1.x|bibcode=2004ConBi..18..878K |s2cid=32063636 }}</ref>
[[File:Male cone of lodgepole pine.jpg|thumb|right|upright=1.04|A cluster of pollen-bearing male cones at [[Mount San Antonio]]]]

''[[Suillus tomentosus]]'', a fungus, produces specialized structures called tuberculate [[ectomycorrhiza]]e with the roots of lodgepole pine (''Pinus contorta'' var. ''latifolia''). These structures have been shown to be the location of concentrations of [[nitrogen-fixing]] bacteria which contribute a significant amount of [[nitrogen]] to tree growth and allow the pines to colonize nutrient-poor sites.<ref name=paul07>{{cite journal| journal=Annals of Botany| volume=99| pages=1101–1109| year=2007| doi=10.1093/aob/mcm061| title=Nitrogen Fixation Associated with Suillus tomentosus Tuberculate Ectomycorrhizae on Pinus contorta var. latifolia| first1=L.R.| last1=Paul| first2=B.K.| last2=Chapman| first3=C.P.| last3=Chanway| issue=6| pmid=17468111 | pmc=3243579}}</ref><ref name=chapman12>{{cite journal| journal=Microbial Ecology| volume=64| issue=4| pages=964–72| year=2012| doi=10.1007/s00248-012-0076-0| pmid=22677953| pmc=3474912| title=Evidence that Northern Pioneering Pines with Tuberculate Mycorrhizae are Unaffected by Varying Soil Nitrogen Levels| first1=W.K.| last1=Chapman| first2=L.R.| last2=Paul | bibcode=2012MicEc..64..964C}}</ref>

Porcupines consume the inner bark of lodgepole pine.<ref name=":0" />

=== Threats ===
Larger members of the species are attacked by [[mountain pine beetle]]s, which it fights with [[Pitch (resin)|pitch]] but can be overwhelmed.<ref name=":0" /> It is also affected by [[blue stain fungus]] (''Grosmannia clavigera''), which the mountain pine beetle carries in its mouth. [[Dwarf mistletoe]] also leeches off the species. Both the threat of pine beetles and dwarf mistletoe are curbed by wildfires, which occurred less in the 20th century due to firefighting. More recently, unthreatening lightning-sparked fires have been allowed to burn in wilderness areas in Idaho and Montana.<ref name=":0" /> Exceptional cold can kill some of the beetles.<ref name=":0" />

A study released in 2011 concluded that ''Pinus contorta'' could experience significant reductions in distribution due to [[climate change]] by the late 21st&nbsp;century.<ref>{{cite journal| journal=Climatic Change| volume=105| pages=313–328| doi=10.1007/s10584-010-9861-2| title=A process-based approach to estimate lodgepole pine (''Pinus contorta'' Dougl.) distribution in the Pacific Northwest under climate change| first1=Nicholas C.| last1=Coops| first2=Richard H.| last2=Waring|date=March 2011| issue=1–2| bibcode=2011ClCh..105..313C| s2cid=54177131}}</ref><ref>{{cite web| title=Climate Change Takes Toll on the Lodgepole Pine| first=John Collins| last=Rudolf| date=28 February 2011| url=http://green.blogs.nytimes.com/2011/02/28/climate-change-takes-toll-on-the-lodgepole-pine| work=Green: A Blog About Energy and the Environment| access-date=1 March 2011}}</ref>

=== As an invasive species ===
''Pinus contorta'' is considered a serious [[invasive species]] of [[wilding conifer]] in [[New Zealand]], along with several other western North American pine species. It is listed on the [[National Pest Plant Accord]] and is prohibited from sale, commercial propagation, and distribution.