View source for Pinus albicaulis

{{Short description|Pine tree species found in North America}}
{{Hatnote|Not to be confused with ''[[Pinus bungeana]]'', also called white-barked pine.}}
{{pp-move-dispute|small=yes}}
{{Use mdy dates|date=December 2022}}
{{Speciesbox
| name = Whitebark pine
| image = whitebark_pine_group.jpg
| image_caption = A stand of whitebark pines at [[Crater Lake National Park]] in [[Oregon]]
| status = EN
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Mahalovich, M. |author2=Stritch, L. |date=2013 |title=''Pinus albicaulis'' |volume=2013 |page=e.T39049A2885918 |doi=10.2305/IUCN.UK.2013-1.RLTS.T39049A2885918.en |access-date=19 November 2021}}</ref>
| status2 = {{TNCStatus}}
| status2_system = TNC
| status2_ref = <ref name="NatureServe">{{cite web |last1=NatureServe |title=''Pinus albicaulis'' |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.128475/Pinus_albicaulis |access-date=5 September 2024 |location=Arlington, Virginia |date=2024}}</ref>
| display_parents = 3
| genus = Pinus
| parent = Pinus subsect. Strobus
| species = albicaulis
| authority = [[George Engelmann|Engelm.]]
| range_map = Pinus albicaulis range map 2.png
| range_map_caption = Natural range of ''Pinus albicaulis''
| synonyms_ref = <ref>{{ThePlantList |id=kew-2563539 |taxon=Pinus albicaulis |authority=}}</ref>
| synonyms =
* ''Apinus albicaulis'' <small>(Engelm.) Rydb.</small>
* ''Pinus cembroides'' <small>Newb. 1857 not Zucc. 1832</small>
* ''Pinus flexilis'' var. ''albicaulis'' <small>(Engelm.) Engelm.</small>
* ''Pinus flexilis'' subsp. ''albicaulis'' <small>(Engelm.) Engelm.</small>
* ''Pinus shasta'' <small>Carrière</small>
}}

[[File:Tuolumne Meadows - Pywiack Dome summit - old pine - 2a.jpg|thumb|''Pinus albicaulis'' is the only type of tree on the summit of [[Pywiack Dome]] in [[Yosemite National Park]]]]
'''''Pinus albicaulis''''', known by the common names '''whitebark pine''', '''white bark pine''', '''white pine''', '''pitch pine''', '''scrub pine''', and '''creeping pine''',<ref>{{Gymnosperm Database |genus=Pinus |species=albicaulis}}</ref> is a [[conifer]] tree native to the mountains of the western United States and Canada, specifically [[subalpine]] areas of the [[Sierra Nevada]], [[Cascade Range]], [[Pacific Coast Ranges]], [[Rocky Mountains]], and [[Ruby Mountains]]. It shares the common name "creeping pine" with [[Creeping pine|several other plants]].

The whitebark pine is typically the highest-elevation [[pine]] tree found in these mountain ranges and often marks the [[tree line]]. Thus, it is often found as ''[[krummholz]]'', trees growing close to the ground that have been dwarfed by exposure. In more favorable conditions, the trees may grow to {{convert|29|m|sp=us}} in height.

==Identification==

[[File:Pinus albicaulis 8581.JPG|right|thumb|upright|''Pinus albicaulis'' leaves are in fascicles (bundles) of five, and the cone is dark purple when immature ([[Mount Rainier National Park]])]]
Whitebark pine is a member of the [[Pinus classification|white pine]] group, the ''[[Pinus]]'' subgenus ''[[Strobus]]'', and the section ''[[Strobus]]''; like all members of this group, the [[leaves]] (needles) are in [[fascicle (botany)|fascicle]]s (bundles) of five<ref name=":0">{{Cite book |last1=Arno |first1=Stephen F. |url=https://www.worldcat.org/oclc/1141235469 |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=26, 35–43 |language=en |oclc=1141235469 |orig-date=1977}}</ref> with a [[deciduous]] sheath. This distinguishes whitebark pine and its relatives from the [[lodgepole pine]] (''Pinus contorta''), with two needles per fascicle, as well as the [[Pinus ponderosa|ponderosa pine]] (''Pinus ponderosa'') and [[Jeffrey pine]] (''Pinus jeffreyi''), which both have three needles per fascicle; all three of these species also have a persistent sheath at the base of each fascicle. Whitebark pine owes its name to the light gray bark of its young specimens.<ref name=":0" />

Distinguishing whitebark pine (''Pinus albicaulis''), from the related [[limber pine]] (''Pinus flexilis''), also a member of the white pine group, is much more difficult, and usually requires seed or pollen [[conifer cone|cones]]. In ''Pinus albicaulis'', the seed-bearing female cones are {{convert|4|–|7|cm|frac=2|sp=us}} long, dark purple when immature,<ref name=":0" /> and do not open on drying, but the scales easily break when they are removed by the [[Clark's nutcracker]] to harvest the seeds; rarely are there intact old cones in the litter beneath the trees. Its pollen cones are scarlet.<ref>{{cite web |last1=Roady |first1=Laura |year=2010 |title=Whitebark Pine |url=http://fwp.mt.gov/mtoutdoors/HTML/articles/portraits/whitebarkpine.htm |website=Montana Outdoors |publisher=Montana Fish, Wildlife & Parks |access-date=15 March 2015}}</ref>

In ''Pinus flexilis'', the cones are {{convert|6|–|12|cm|frac=2|abbr=on}} long, green when immature, and open to release the seeds; the scales are not fragile. Their pollen cones are yellow, and there are usually intact old cones found beneath them.

Whitebark pine can also be hard to distinguish from the [[western white pine]] (''Pinus monticola'') in the absence of cones. However, whitebark pine needles are yellow-green<ref name=":0" /> and entire (smooth when rubbed gently in either direction), whereas western white pine needles are silvery green<ref name=":0" /> and finely serrated (feeling rough when rubbed gently from tip to base). Whitebark pine needles are also usually shorter, {{convert|3|–|7|cm|frac=2|abbr=on}} long,<ref name=":0" /> though still overlapping in size with the larger {{convert|5|–|10|cm|0|abbr=on}} needles of the western white pine.

==Distribution==
Whitebark pine (''Pinus albicaulis'') can be found at high elevation in the [[Rocky Mountains]] from central [[British Columbia]] to western [[Wyoming]].<ref name=":0" /> It occurs in the timberline zone of the [[Cascade Range|Cascades]] and coastal ranges from British Columbia to the [[Sierra Nevada (U.S.)|Sierra Nevada]], as well as most high ranges between the Rockies and Cascades, such as the [[Blue Mountains (Pacific Northwest)|Blue Mountains]].<ref name=":0" /> It is also populous in subalpine forests of Montana and Idaho.<ref name=":0" />

==Ecology==

[[File:WhitebarkPine 7467t.jpg|right|thumb|upright|The whitebark pine, ''Pinus albicaulis'', at [[Mount Rainier National Park]]]]
The whitebark pine is an important source of food for many [[granivorous]] birds and small mammals, including most importantly the [[Clark's nutcracker]] (''Nucifraga columbiana''), the major seed disperser of the pine.<ref name=":0" /> Clark's nutcrackers each cache about 30,000 to 100,000 seeds each year in small, widely scattered caches, usually under {{convert|2|to|3|cm|in|frac=4|abbr=on}} of soil or gravelly substrate. Nutcrackers retrieve these seed caches during times of food scarcity and to feed their young. Cache sites selected by nutcrackers are often favorable for germination of seeds and survival of seedlings. Those caches not retrieved by the time the snow melts contribute to forest regeneration. Consequently, whitebark pine often grows in clumps of several trees, originating from a single cache of two to 15 or more seeds.

Other animals also depend upon the whitebark pine. [[Douglas squirrel]]s cut down and store whitebark pine cones in their [[midden]]s. [[Grizzly bear]]s and [[American black bear]]s often raid squirrel middens for whitebark pine seeds,<ref name=":0" /> an important pre-hibernation food. Squirrels, [[northern flicker]]s, and [[mountain bluebird]]s often nest in whitebark pines, and [[elk]] and [[blue grouse]]<ref name=":0" /> use whitebark pine communities as summer habitat.

Fallen needles under these trees serve as beds that are used by deer and wild sheep seeking shelter during stormy weather.<ref>{{cite book |last=Peattie |first=Donald Culross |author-link=Donald C. Peattie |title=A Natural History of Western Trees |year=1953 |publisher=[[Bonanza Books]] |location=New York |page=33}}</ref>

=== Threats ===
The whitebark pine has been classified as endangered by the [[International Union for Conservation of Nature|IUCN]].<ref name="iucn status 19 November 2021" /> Severe population decline in whitebark pine communities is attributed to various causes, most significantly infection with [[white pine blister rust]], recent outbreaks of [[mountain pine beetle]]s (2000–2014), disturbances in wildland [[fire ecology]] (including [[Wildfire suppression|fire suppression]]), forest succession, and climate change. A study in the mid-2000s showed that whitebark pine had declined by 41&nbsp;percent in the western Cascades due to two primary threats: blister rust and pine beetles.<ref name="seattle2011" /> Whitebark deaths in [[North Cascades National Park]] doubled from 2006 to 2011.<ref name="seattle2011" />

==== White pine blister rust ====
{{Further|Cronartium ribicola}}
Many stands of ''Pinus albicaulis'' across the species' entire natural range are infected with white pine blister rust (''Cronartium ribicola''), a [[fungus|fungal]] disease introduced from Europe. In the northern Rocky Mountains of the United States, whitebark pine mortality in some areas exceeds 90&nbsp;percent, where the disease infests nearly {{convert|143000|acre|km2}}. ''Cronartium ribicola'' occurs in whitebark pine to the northern limits of the species in the coastal ranges of British Columbia and the Canadian Rocky Mountains. The blister rust has also devastated the commercially valuable western white pine in these areas and made serious inroads in limber pine (''Pinus flexilis'') populations as well. Nearly 80&nbsp;percent of whitebark pines in [[Mount Rainier National Park]] are infected with blister rust.<ref name="seattle2011"/>

There is currently no effective method for controlling the spread and effects of blister rust. However, a small number of trees (fewer than 5%) in most populations harbor genetic resistance to blister rust.<ref name=":0" /> [[Restoration ecology|Restoration efforts]] undertaken by the [[U.S. Forest Service]], [[Bureau of Land Management]], and [[National Park Service]] in the northern Rocky Mountains involve harvesting cones from potentially and known resistant whitebark pines, growing seedlings, and outplanting seedlings in suitable sites. In [[California]], where the blister rust is far less severe, whitebark pine is still fairly common in the [[Sierra Nevada (U.S.)|High Sierras]].<ref>{{Cite news |last=Brown |first=Matthew |date=2022-12-14 |title=Whitebark pine that feeds grizzlies is threatened, US says |url=https://apnews.com/article/wildfires-science-trees-bears-us-fish-and-wildlife-service-592a0fcf8025bd3fb48eac406716f181 |access-date=2022-12-14 |work=AP News |language=en}}</ref>

==== Mountain pine beetle ====
Unusually large outbreaks of mountain pine beetle (''Dendroctonus ponderosae''), a species of [[bark beetle]] native to western North America, have also contributed significantly to the widespread destruction of whitebark pine stands.<ref>{{cite book |display-authors=1 |author1=Kershner, Bruce |author2=Moore, Gerry |author3=Tufts, Craig |author4=Mathews, Daniel |author5=Nelson, Gil |author6=Spellenberg, Richard |author7=Thieret, John W. |author8=Purinton, Terry |author9=Block, Andrew |title=National Wildlife Federation Field Guide to Trees of North America |publisher=Sterling |location=New York |year=2008 |page=80 |isbn=978-1-4027-3875-3}}</ref> The beetles both lay their eggs and introduce pathogenic fungi into their host trees, which include many other species of pine, and the combination of larval feeding and fungal colonization is typically sufficient to kill old or unhealthy trees. However, the beetles have recently expanded their attacks to younger, healthier trees as well as older trees, and climate change has been implicated as the primary culprit. Since 2000, the climate at high elevations has warmed enough for the beetles to reproduce within whitebark pine, often completing their life cycle within one year and enabling their populations to grow exponentially. Entire forest vistas, like that at Avalanche Ridge near [[Yellowstone National Park]]’s east gate, have become expanses of dead gray whitebarks.<ref>{{cite news|first=Charles|last=Petit|title=In the Rockies, Pines Die and Bears Feel It|work=New York Times|date=January 30, 2007|url=http://www.whitebarkfound.org/nyt-article.html|access-date=July 7, 2012|archive-url=https://web.archive.org/web/20120206062248/http://www.whitebarkfound.org/nyt-article.html|archive-date=February 6, 2012|url-status=dead}}</ref> Scientists have attributed the recent warming trend to anthropogenic [[global warming]].<ref name="seattle2011">{{cite web| url= https://www.seattletimes.com/seattle-news/climate-change-beetle-may-doom-rugged-pine/ | title= Climate change, beetle may doom rugged pine | date= November 6, 2011 | first=Craig |last=Welch | publisher= Seattle Times | access-date=2022-09-09}}</ref><ref>{{cite web |url=http://kuow.org/post/can-dying-tree-species-be-saved-crater-lake |title=Can A Dying Tree Species Be Saved At Crater Lake? |author=Ross Reynolds |date=June 9, 2015 |website=KUOW}}</ref>

In 2007, the [[U.S. Fish and Wildlife Service]] estimated that beetles had killed whitebark pines across {{convert|500000|acre}} in the West, while in 2009, beetles were estimated to have killed trees on {{convert|800000|acre}}, the most since record-keeping began.<ref name="seattle2011"/> The pine beetle upsurge has killed nearly 750,000 whitebark pines in the [[Greater Yellowstone Ecosystem]] alone.{{As of?|date=May 2012}}

==== Fire suppression ====
Fire suppression has led to slow population declines over the last century by altering the health and composition dynamics of stands without the fire ecology balancing their habitat and suppressing insect-disease threats.<ref>{{cite book|last1 = Kendall|first1 = K.C|first2 = R.E.|last2 = Keane|contribution = Whitebark pine decline: Infection, mortality, and population trends|editor1-last = Tomback|editor1-first = D.F.|editor1-link=Diana Tomback|editor2-last = Arno|editor2-first = S.F.|editor3-first = R.E.|editor3-last = Keane|year = 2001|title = Whitebark pine communities: ecology and restoration|publisher = Island Press|location = Washington, D.C.|pages = 221–242}}</ref> In the absence of low-level wildfire cycles, whitebark pines in these stands are replaced by more shade-tolerant, fire-intolerant species such as [[Abies lasiocarpa|subalpine fir]] (''Abies lasiocarpa'') and [[Picea engelmannii|Engelmann spruce]] (''Picea engelmannii''). In addition, [[senescent]] and blister rust-infected pine trees are not destroyed by natural periodic ground fires, further diminishing the whitebark pine forest's vitality and survival.<ref>{{cite book |last=Lorenz |first=T. J.|author2=Aubry, C. |author3=Shoal, R. |year=2008|title=A review of the literature on seed fate in whitebark pine and the life history traits of Clark's nutcracker and pine squirrels|location=Portland, OR |publisher=U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Research Station|url=http://www.fs.fed.us/pnw/pubs/pnw_gtr742.pdf|oclc=222226528 }}</ref>

=== Protective efforts ===
In 2012 the Canadian federal government declared whitebark pine [[endangered species|endangered]] in accordance with the [[Species at Risk Act]]. Accordingly, it became the first federally listed endangered tree in western Canada.<ref>{{cite news |last1=Zimmer |first1=Carl |title=For Trees Under Threat, Flight May Be Best Response |work=The New York Times |url=https://www.nytimes.com/2014/09/23/science/under-theat-flight-may-be-best-response-for-trees.html |agency=New York Times |date=13 January 2023}}</ref> In 2022 the [[U.S. Fish & Wildlife Service]] also acted. It listed whitebark pine in the lowest category of vulnerability: "threatened." Four distinct threats were described, beginning with [[white pine blister rust]] as "the primary stressor." [[Mountain pine beetle]], altered fire regimes, and "the effects of climate change" add to the challenges.<ref>{{cite journal |last1=U.S. Fish and Wildlife Service |title=Endangered and Threatened Wildlife and Plants; Threatened Species Status With Section 4(d) Rule for Whitebark Pine (Pinus albicaulis) |journal=Federal Register |date=15 December 2022 |volume=87 |issue=240 |pages=76882–76917 |url=https://www.govinfo.gov/content/pkg/FR-2022-12-15/pdf/2022-27087.pdf#page=1}}</ref> This listing marks the first occasion in which a tree regarded as ecologically important over a vast range in the United States is acknowledged as vulnerable to extinction.<ref>{{cite web |last1=Center for Biological Diversity |title=Whitebark Pine Protected as Threatened Under Endangered Species Act |url=https://biologicaldiversity.org/w/news/press-releases/whitebark-pine-protected-as-threatened-under-endangered-species-act-2022-12-14/#:~:text=%E2%80%94%20The%20U.S.%20Fish%20and%20Wildlife,%2C%20Montana%2C%20Wyoming%20and%20Nevada. |access-date=13 January 2023}}</ref>

In response to the ongoing decline of the tree throughout its range, the Whitebark Pine Ecosystem Foundation was formed. Their mission is to raise awareness and promote conservation by sponsoring restoration projects, publishing a newsletter called "Nutcracker Notes", and hosting an annual science and management workshop for anyone interested in whitebark pine.<ref>[http://www.whitebarkfound.org Whitebark Pine Ecosystem Foundation]</ref> This U.S. group collaborates closely with the Whitebark Pine Ecosystem Foundation of Canada.<ref>[http://www.whitebarkpine.ca Whitebark Pine Ecosystem Foundation of Canada]</ref>

==Uses==
[[File:Whitebark pine seeds, Thoma Ridge Hungry Horse Glacier View Ranger District (51795752924).jpg|thumb|upright|Whitebark pine seeds]]
Many Native Americans, including the [[Salish peoples]], have been known to eat the seeds from the cones of this tree.<ref>{{cite book |last=Whitney |first=Stephen |title=Western Forests (The Audubon Society Nature Guides) |date=1985 |publisher=Knopf |location=New York |isbn=0-394-73127-1 |page=[https://archive.org/details/westernforests00whit/page/408 408] |url=https://archive.org/details/westernforests00whit/page/408 }}</ref><ref name=":0" /> They were roasted, made into porridge, and mixed with dry berries.<ref name=":0" />

{{clear right}}
==References==
{{Reflist}}

==Further reading==
{{Refbegin}}
* {{cite book | last1 = Chase| first1 = J. Smeaton| author-link1 = J. Smeaton Chase|others=[[Carl Eytel|Eytel, Carl]] (illustrations)|title = Cone-bearing Trees of the California Mountains |chapter=''Pinus albicaulis'' (White-bark-pine, White-pine, Dwarf-pine, Alpine white-pine)|chapter-url = https://archive.org/details/conebearingtrees00chas/page/52/mode/2up| location = Chicago | publisher = [[A.C. McClurg & Co.]] | pages = 52–54 |year=1911 | oclc = 3477527|lccn=11004975}}
* {{cite book |editor1-last=Keane |editor1-first=Robert E. |editor2-last=Tomback |editor2-first=Diana F. |editor2-link=Diana Tomback|editor3-last=Murray |editor3-first=Michael P. |display-editors=3 |editor4-last=Smith |editor4-first=Cyndi M. |year=2010 |url=http://www.fs.fed.us/rm/pubs/rmrs_p063.html |title=The future of high-elevation, five-needle white pines in Western North America: Proceedings of the High Five Symposium 28–30 June 2010 |id=Proceedings RMRS-P-63 |location=Fort Collins, CO |publisher=U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station}}
* {{cite book|last=Lanner|first=R. M.|year=1996|title=Made for each other: a symbiosis of birds and pines|publisher=OUP|isbn=0-19-508903-0}}
* {{cite journal|last1=Logan|first1=J.A.|last2=Regniere|first2=J.|last3=Powell|first3=J.A.|year=2003|title=Assessing the Impacts of Global Warming on Forest Pest Dynamics|journal=Frontiers in Ecology and the Environment |volume=1 |issue=3 |pages=130–137 |doi=10.1890/1540-9295(2003)001[0130:ATIOGW]2.0.CO;2|doi-access=free}}
* {{cite journal|last=Murray|first=M.P.|year=2005|url=http://www.npsoregon.org/kalmiopsis/kalmiopsis12/timberlines.pdf|title=Our Threatened Timberlines: The Plight of Whitebark Pine Ecosystems |journal=Kalmiopsis |volume=12 |pages=25–29}}
* {{cite book|last=Schwandt|first=J.|year=2006|title=Whitebark pine in peril: A case for restoration|publisher=USDA, Forest Service, Northern Region|id=R1-06-28}}
* {{cite book|editor1-last=Tomback|editor1-first=D.F.|editor1-link=Diana Tomback|editor2-last=Arno|editor2-first=S.F.|editor3-first=R.E.|editor3-last=Keane|year=2001|title=Whitebark pine communities: ecology and restoration|publisher=Island Press |location=Washington, D.C.}}
{{Refend}}

==External links==
{{Commons and category|Pinus albicaulis}}
* {{Jepson Manual |id=195,210,211 |link=1}}
* {{cite web| archive-url= https://web.archive.org/web/20070714142635/http://biology.usgs.gov/s+t/SNT/noframe/wm147.htm |archive-date= 2007-07-14 |publisher=United States Geological Survey |title= Whitebark Pine| url= http://biology.usgs.gov/s+t/SNT/noframe/wm147.htm}}
* {{CalPhotos|Pinus|albicaulis}}

{{Taxonbar|from=Q761480}}
{{Authority control}}

[[Category:Pinus|albicaulis]]
[[Category:Flora of Alberta]]
[[Category:Flora of British Columbia]]
[[Category:Flora of California]]
[[Category:Flora of Idaho]]
[[Category:Flora of Montana]]
[[Category:Flora of Nevada]]
[[Category:Flora of Oregon]]
[[Category:Flora of Washington (state)]]
[[Category:Flora of Wyoming]]
[[Category:Plants described in 1863]]
[[Category:Taxa named by George Engelmann]]
[[Category:Trees of Northern America]]