- Male cones of a limber pine, eastern Sierra Nevada, California
- Limber pine cone from San Jacinto Mountains
Limber pine | |
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Limber pine on Spruce Mountain, Nevada | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Gymnospermae |
Division: | Pinophyta |
Class: | Pinopsida |
Order: | Pinales |
Family: | Pinaceae |
Genus: | Pinus |
Subgenus: | P. subg. Strobus |
Section: | P. sect. Quinquefoliae |
Subsection: | P. subsect. Strobus |
Species: | P. flexilis |
Binomial name | |
Pinus flexilis E.James, 1824 | |
Natural range | |
Synonyms [3] | |
Pinus flexilis, the limber pine, is a species of pine tree in the family Pinaceae that occurs in the mountains of the Western United States, Mexico, and Canada. It is also called Rocky Mountain white pine.
A limber pine in Eagle Cap Wilderness, Oregon, has been documented as over 2,000 years old, and another one was confirmed at 1,140 years old. [4] [5] Another candidate for the oldest limber pine was identified in 2006 near the Alta Ski Area in Utah; called "Twister", the tree was confirmed to be at least 1,700 years old and thought to be even older. [6]
Its pliant branches gives it the common name "limber" and specific epithet flexilis. Its needles are about 8 centimeters (3+1⁄4 in) long and a dark, blueish green. [7] Its bark is heavily creased and dark grey. Its pale wood is lightweight and soft.
Pinus flexilis is typically a high-elevation pine, often marking the tree line either on its own, or with whitebark pine (Pinus albicaulis), either of the bristlecone pines, or lodgepole pine (Pinus contorta). In favorable conditions, it makes a tree to 20 metres (65 feet), rarely 25 m (80 ft) tall. On exposed tree line sites, mature trees are much smaller, reaching heights of only 5–10 m (15–35 ft). [8] In steeply-sloping, rocky, and windswept terrain in the Rocky Mountains of southern Alberta, limber pine is even more stunted, occurring in old stands where mature trees are consistently less than 3 m (10 ft) in height. [9]
One of the world's oldest living limber pine trees grows on the banks of the upper North Saskatchewan River at Whirlpool Point in Alberta. Recent measurements give a maximum girth of 185". In 1986, a core sample 10 cm was retrieved by two researchers who counted 400 rings. Extrapolating this data gives an age close to 3,000 years.
Pinus flexilis is a member of the white pine group, Pinus subgenus Strobus , and like all members of that group, the leaves ('needles') are in fascicles (bundles) of five, [7] with a deciduous sheath. This distinguishes it from the lodgepole pine, with two needles per fascicle, and the bristlecone pines, which share five needles per fascicle but have a semi-persistent sheath.
Distinguishing limber pine from the related whitebark pine (P. albicaulis), also a white pine, is very much more difficult, and can only easily be done by the cones. In limber pine, the cones are 6–15 cm (2+1⁄4–6 in) long [7] where the species overlap, green when immature, and open to release the seeds; the scales are not fragile. In whitebark pine, the cones are 4–7 cm (1+1⁄2–2+3⁄4 in) long, dark purple when immature, and do not open on drying, but are fragile and are pulled apart by birds to release the seeds. [10] A useful clue is that whitebark pines almost never have intact old cones lying under them, whereas limber pines usually do. [11]
In the absence of cones, limber pine can also be hard to tell from Western white pine (P. monticola) where they occur together in the northern Rockies and the Sierra Nevada east slope. The most useful clue here is that limber pine needles are entire (smooth when rubbed gently in both directions), whereas Western white pine needles are finely serrated (feeling rough when rubbed gently from tip to base). Limber pine needles are also usually shorter, 4–7 cm (1+1⁄2–2+3⁄4 in) long, while western white pine needles are 5–10 cm (2–4 in), though the ranges overlap.
The largest part of the limber pine's range is in the Rocky Mountains, from southwest Alberta [7] and southeastern British Columbia south through Colorado and New Mexico into the northern states of Mexico. It is also found through the Great Basin [7] states of Nevada and Utah, in the eastern Sierra Nevada and White Mountains of Northern California, and in the San Bernardino and San Gabriel Mountains of the Transverse Ranges in Southern California. Continuing south the species is found in the San Jacinto Mountains, Santa Rosa Mountains,[ citation needed ] and Hot Springs Mountain [ citation needed ] of the Peninsular Ranges. There are small disjunct populations in eastern Oregon, in western North Dakota and Nebraska, [12] and in the Black Hills of South Dakota. [13] [8] It is found at a wide range of altitudes depending on the latitude, from 850 to 3,810 m (2,790 to 12,500 ft). In the northern half of its range, it grows in the montane zone near the lower tree line; in the middle of its range between the 45th and 40th parallels, it grows on windswept sites in the montane and subalpine zones; and in the southern part of its range, it grows mainly at high elevations in the subalpine zone near the upper tree line. [12] It can more often be found at the outer fringes of a forest than in the forest itself. [7]
Pinus flexilis is an important source of food for several species, including red squirrels and Clark's nutcrackers, the latter being an important distributor of seeds. [14] [7] There is evidence that limber pines co-evolved with Clark's nutcrackers, which are the primary dispersers of the seeds. [15] [14] [16] In a relic, low elevation population, seeds are also dispersed by small rodents. [17] American black bears and grizzly bears may raid squirrel caches for limber pine nuts. [7] Squirrels, Northern flickers, and mountain bluebirds often nest in the trees. There is some evidence that P. flexilis has a symbiotic relationship with nitrogen-fixing bacteria that inhabit the needles. [18]
The species is generally shade tolerant and resistant to fire, but does not thrive in dense habitats, instead occurring in areas relatively hostile to other species. [19] [7]
Limber pine is susceptible to white pine blister rust, [7] caused by Cronartium ribicola, a fungus that was introduced accidentally from Europe. Limber pine mortality is high in many areas throughout its range, except Arizona, where it has not yet been found. However, there is little hope of controlling the blister rust in existing trees. Research is under way, locating and breeding from the occasional naturally resistant limber pines, and by studying the resistance mechanisms of the European and Asian white pines (e.g. Swiss pine, Macedonian pine), which are strongly resistant to the disease.
The tree has also been damaged by bark beetle epidemics, particularly at drought-affected low elevations. [7]
The popular cultivar P. flexilis 'Vanderwolf's Pyramid' is widely available as an ornamental tree for gardens. 'Vanderwolf's Pyramid' derives from P. reflexa, though it is usually listed in nursery catalogs under P. flexilis.
The Southwestern white pine is popular as a windbreak tree or an ornamental tree due to its drought tolerance. It is also grown as a Christmas tree, liked for the soft needles but with stiffer branches than an Eastern white pine.
The large seeds are edible, [20] and were reportedly consumed by Native Americans in Montana. [7]
A pine is any conifer tree or shrub in the genus Pinus of the family Pinaceae. Pinus is the sole genus in the subfamily Pinoideae.
The term bristlecone pine covers three species of pine tree. All three species are long-lived and highly resilient to harsh weather and bad soils. One of the three species, Pinus longaeva, is among the longest-lived life forms on Earth. The oldest of this species is more than 4,800 years old, making it the oldest known individual of any species. Many scientists are curious as to why this tree is able to live so long. In one study, they discovered that Pinus longaeva has higher levels of telomerase activity, which further slows or prevents the attrition rate of telomeres. This potentially contributes to the extended life of the bristlecone pine.
Clark's nutcracker, sometimes referred to as Clark's crow or woodpecker crow, is a passerine bird in the family Corvidae, native to the mountains of western North America. The nutcracker is an omnivore, but subsists mainly on pine nuts, burying seeds in the ground in the summer and then retrieving them in the winter by memory. The bird was described by the Lewis and Clark Expedition, with William Clark first observing it in 1805 along the banks of the Salmon River, a tributary of the Columbia River.
Pinus albicaulis, known by the common names whitebark pine, white bark pine, white pine, pitch pine, scrub pine, and creeping pine, 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 several other plants.
Western white pine, also called silver pine and California mountain pine, is a species of pine in the family Pinaceae. It occurs in mountain ranges of northwestern North America and is the state tree of Idaho.
Pinus lambertiana is the tallest and most massive pine tree, and has the longest cones of any conifer. The species name lambertiana was given by the Scottish botanist David Douglas, who named the tree in honour of the English botanist, Aylmer Bourke Lambert. It is native to coastal and inland mountain areas along the Pacific coast of North America, as far north as Oregon and as far south as Baja California in Mexico.
Pinus strobiformis, commonly known as southwestern white pine, Mexican white pine or Chihuahua white pine, is a medium-sized white pine tree whose native habitat is in southwestern United States and Mexico. It is typically a high-elevation pine growing mixed with other conifers.
Pinus contorta, with the common names lodgepole pine and shore pine, and also known as twisted pine, and contorta pine, is a common tree in western North America. It is common near the ocean shore and in dry montane forests to the subalpine, but is rare in lowland rain forests. Like all pines, it is an evergreen conifer.
Pinus ponderosa, commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine, is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the most widely distributed pine species in North America.
Pinus longaeva is a long-living species of bristlecone pine tree found in the higher mountains of California, Nevada, and Utah. Methuselah is a bristlecone pine that is 4,856 years old and has been credited as the oldest known living non-clonal organism on Earth. To protect it, the exact location of this tree is kept secret. In 1987, the bristlecone pine was designated one of Nevada's state trees.
Pinus cembra, also known as Swiss pine, Swiss stone pine, Arolla pine, Austrian stone pine, or just stone pine, is a species of pine tree in the subgenus Strobus.
Pinus sibirica, or Siberian pine, in the family Pinaceae is a species of pine tree that occurs in Siberia from 58°E in the Ural Mountains east to 126°E in the Stanovoy Range in southern Sakha Republic, and from Igarka at 68°N in the lower Yenisei valley, south to 45°N in central Mongolia.
Pinus edulis, the Colorado pinyon, two-needle piñon, pinyon pine, or simply piñon, is a pine in the pinyon pine group native to the Southwestern United States, used for its edible pine nuts.
Pinus monophylla, the single-leaf pinyon, is a pine in the pinyon pine group, native to North America. The range is in southernmost Idaho, western Utah, Arizona, southwest New Mexico, Nevada, eastern and southern California and northern Baja California.
Pinus aristata, the Rocky Mountain bristlecone pine or Colorado bristlecone pine is a long-lived species of bristlecone pine tree native to the United States. It is found in the Rocky Mountains in Colorado and northern New Mexico, with an isolated population in the San Francisco Peaks of Arizona. It is found at very high altitudes, from 2,100 to 4,000 meters in cold, dry subalpine climate conditions, often at the tree line, although it also forms extensive closed-canopy stands at somewhat lower elevations.
The Rocky Mountains subalpine zone is the biotic zone immediately below tree line in the Rocky Mountains of North America. In northern New Mexico, the subalpine zone occupies elevations approximately from 9,000 to 12,000 feet ; while in northern Alberta, the subalpine zone extends from 1,350 to 2,300 metres.
The Sierra Nevada subalpine zone refers to a biotic zone below treeline in the Sierra Nevada mountain range of California, United States. This subalpine zone is positioned between the upper montane zone at its lower limit, and tree line at its upper limit.
Krummholz — also called knieholz — is a type of stunted, deformed vegetation encountered in the subarctic and subalpine tree line landscapes, shaped by continual exposure to fierce, freezing winds. Under these conditions, trees can only survive where they are sheltered by rock formations or snow cover. As the lower portion of these trees continues to grow, the coverage becomes extremely dense near the ground. In Newfoundland and Labrador, the formation is known as tuckamore. Krummholz trees are also found on beaches such as the Oregon coast, where trees can become much taller than their subalpine cousins.