- Whitebark Pine
name = Whitebark Pine
status = VU
status_system = iucn2.3
image_width = 240px
image_caption = A stand of Whitebark Pines
classis = Pinopsida
genus = "Pinus"
subgenus = "Strobus"
species = "P. albicaulis"
binomial = "Pinus albicaulis"
binomial_authority = Engelm.
The Whitebark Pine ("Pinus albicaulis"; family
Pinaceae) occurs in the mountains of the Western United Statesand Canada, specifically the subalpineareas of the Sierra Nevada, the Cascade Range, the Pacific Coast Ranges, and the northern Rocky Mountains(including the Greater Yellowstone Ecosystem). The Whitebark Pine is typically the highest-elevation pine tree of these mountains, marking the tree line. Thus, they are often found as "krummholz", trees dwarfed by exposure and growing close to the ground. In more favourable conditions, trees may grow to 20 m in height, although some can reach up to 27 m.
Whitebark Pine is a member of the white pine group, "
Pinus" subgenus " Strobus", section " Strobus" and like all members of that group, the leaves ('needles') are in fascicles (bundles) of five, with a deciduous sheath. This distinguishes Whitebark Pine and relatives from the Lodgepole Pine, with two needles per fascicle, and Ponderosa Pineand Jeffrey Pine, which both have three per fascicle; these three all also have a persistent sheath at the base of each fascicle.
Distinguishing Whitebark Pine from the related
Limber Pine, also a white pine, is much more difficult, and requires seed or pollen cones. In Whitebark Pine, the cones are 4-7 cm long, dark purple when immature, and do not open on drying, but the scales easily break when they are removed by Clark's Nutcracker(see below) to harvest the seeds. In Limber Pine, the cones are 6-12 cm long, green when immature, and open to release the seeds; the scales are not fragile. Whitebark Pines almost rarely has intact old cones lying under them, whereas Limber Pines usually do. The pollen cones of Whitebark Pine are scarlet, and yellow in Limber Pine.
Whitebark Pine can also be hard to distinguish from
Western White Pinein the absence of cones. However, Whitebark Pine needles are entire (smooth when rubbed gently in either direction), whereas Western White Pine needles are finely serrated (feeling rough when rubbed gently from tip to base). Whitebark Pine needles are also usually shorter, 4-7 cm long, to Western White Pine's 5-10 cm (though note the overlap).
The Whitebark Pine is an important source of food for many granivorous birds and small mammals, including most importantly the
Clark's Nutcracker, the major seed disperser of the pine. Clark's Nutcrackers each cache about 30,000 to 100,000 each year in small, widely scattered caches usually under 2 to 3 cm 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 time snow melts contribute to forest regenetation. Consequently,Whitebark Pine often grows in clumps of several trees, originating from a single cache of 2-15 or more seeds. Douglas Squirrels cut down and store Whitebark Pine cones in their middens. Grizzly Bears and American Black Bears often raid squirrel middens for Whitebark Pine seeds, an important pre-hibernation food. Squirrels, Northern Flickers, and Mountain Bluebirds often nest in Whitebark Pines, and elk and Blue Grouse use Whitebark Pine communities as summer habitat.
Many stands of Whitebark Pine nearly rangewide are infected with White Pine Blister Rust ("Cronartium ribicola"), a fungal disease that was introduced from
Europe. In the northern Rocky Mountains of the U.S., whitebark Pine mortality in some areas exceeds 90%. 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 populations as well. There is currently no way to stop 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. There have been some restoration efforts by the U.S. Forest Service and National Park Service in the northern Rocky Mountains. Restoration efforts involve harvesting cones from potentially and known resistant Whitebark Pine, growing seedlings, and outplanting seedlings in suitable sites.
The threat to Whitebark Pine by blister rust is currently complicated by widespread outbreaks of
Mountain Pine Beetlein the western U.S. and Canada. Since 2000, the climate at high elevations has been warm enough for the beetles to reproduce within Whitebark Pine, often completing their life cycle within one year and enabling their populations to grow exponentially. These higher temperature trends have been attributed by some researchers to global warming. Regardless of cause, the pine beetle upsurge has killed large numbers of Whitebark Pine (nearly 3/4 million in the Greater Yellowstone Ecosystem alone). Mountain pine beetles jeopardize current and future Whitebark Pine restoration efforts, because they are killing trees genetically resistant to white pine blister rust.
* Listed as Vulnerable (VU A1c v2.3)
*Lanner, R. M. 1996. "Made for each other: a symbiosis of birds and pines". OUP. ISBN 0-19-508903-0
*Logan, J. A., Regniere, J., and Powell, J. A. 2003. Assessing the Impacts of Global Warming on Forest Pest Dynamics. "Frontiers in Ecology and the Environment" 1(3): 130-137.
*Schwandt, J. 2006. Whitebark pine in peril: A case for restoration. USDA, Forest Service, Northern Region, R1-06-28.
*Tomback, D. F., Arno, S. F., and R. E. Keane (eds.) 2001. Whitebark pine communities: ecology and restoration. Island Press, Washington, D. C.
* [http://www.pinetum.org/cones/PNStrobus.htm "Pinus albicaulis" cone pic (scroll to foot of page)]
* [http://www.conifers.org/pi/pin/albicaulis.htm Gymnosperm Database: "Pinus albicaulis"]
* [http://plants.usda.gov/java/profile?symbol=PIAL USDA Plants Profile: "Pinus albicaulis"]
* [http://www.efloras.org/object_page.aspx?object_id=6621&flora_id=1 Flora of North America]
* [http://biology.usgs.gov/s+t/SNT/noframe/wm147.htm The Whitebark Pine (at USGS)]
* [http://www.nrmsc.usgs.gov/research/whitebar.htm Whitebark Pine Communities (at USGS)]
* [http://www.whitebarkfound.org Whitebark Pine Ecosystem Foundation]
Wikimedia Foundation. 2010.
Look at other dictionaries:
whitebark pine — baltakamienė pušis statusas T sritis vardynas apibrėžtis Pušinių šeimos dekoratyvinis, medieninis augalas (Pinus albicaulis), paplitęs Šiaurės Amerikoje. atitikmenys: lot. Pinus albicaulis angl. alpine whitebark pine; whitebark pine vok.… … Lithuanian dictionary (lietuvių žodynas)
whitebark pine — noun small pine of western North America; having smooth grey white bark and soft brittle wood; similar to limber pine • Syn: ↑whitebarked pine, ↑Pinus albicaulis • Hypernyms: ↑white pine * * * noun also whitebar … Useful english dictionary
alpine whitebark pine — baltakamienė pušis statusas T sritis vardynas apibrėžtis Pušinių šeimos dekoratyvinis, medieninis augalas (Pinus albicaulis), paplitęs Šiaurės Amerikoje. atitikmenys: lot. Pinus albicaulis angl. alpine whitebark pine; whitebark pine vok.… … Lithuanian dictionary (lietuvių žodynas)
alpine whitebark pine — noun : a timber tree (Pinus albicaulis) found in the Rocky mountains and in California … Useful english dictionary
Pine — This article is about the tree. For other uses of the term pine , see Pine (disambiguation). Pine Japanese Red Pine (Pinus densiflora), North Korea Sc … Wikipedia
pine — pine1 pinelike, adj. /puyn/, n. 1. any evergreen, coniferous tree of the genus Pinus, having long, needle shaped leaves, certain species of which yield timber, turpentine, tar, pitch, etc. Cf. pine family. 2. any of various similar coniferous… … Universalium
whitebark — ˈ ̷ ̷ˌ ̷ ̷ noun 1. : any of several American trees (as the white poplar or whitebark pine) with pale or whitish bark 2. Australia : a blueberry ash (Elaeocarpus cyaneus) … Useful english dictionary
pine — I (New American Roget s College Thesaurus) v. i. languish, long, crave; wither, droop. See dejection, disease, desire. II (Roget s IV) n. Varieties of pine include: white, stone, mugo, whitebark, foxtail, bristlecone, nut, singleleaf, piñon,… … English dictionary for students
whitebark — noun The North American pine Pinus albicaulis, found in mountainous and subalpine regions, often as krummholz … Wiktionary
Limber Pine — Taxobox name = Limber Pine status = LR/lc | status system = IUCN2.3 image width = 240px image caption = Limber pine in the Craters of the Moon National Monument, Idaho regnum = Plantae divisio = Pinophyta classis = Pinopsida ordo = Pinales… … Wikipedia