Pinus longaeva
Pinus longaeva | |
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A specimen in the Ancient Bristlecone Pine Forest, Sierra Nevada,Mountains, California | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Gymnospermae |
Division: | Pinophyta |
Class: | Pinopsida |
Order: | Pinales |
Family: | Pinaceae |
Genus: | Pinus |
Subgenus: | P. subg. Strobus
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Section: | P. sect. Parrya
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Subsection: | P. subsect. Balfourianae
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Species: | P. longaeva
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Binomial name | |
Pinus longaeva | |
Pinus longaeva (commonly referred to as the Great Basin bristlecone pine, intermountain bristlecone pine, or western bristlecone pine)
Description
It is a medium-size tree, reaching 5 to 15 m (16 to 49 ft) tall and with a trunk diameter of up to 2.5 to 3.6 m (8 to 12 ft). The bark is bright orange-yellow, thin and scaly at the base of the trunk. The needles are in fascicles of five, stout, 2.5 to 4 cm (1 to 1+1⁄2 in) long, deep green to blue-green on the outer face, with stomata confined to a bright white band on the inner surfaces. The leaves show the longest persistence of any plant, with some remaining green for 45 years (Ewers & Schmid 1981).
The cones are ovoid-cylindrical, 5 to 10 cm (2 to 4 in) long and 3 to 4 cm (1 to 1+1⁄2 in) broad when closed, green or purple at first, ripening orange-buff when 16 months old, with numerous thin, fragile scales, each scale with a bristle-like spine 2 to 5 mm (1⁄16 to 3⁄16 in) long. The cones open to 4 to 6 cm (1+1⁄2 to 2+1⁄2 in) broad when mature, releasing the seeds immediately after opening. The seeds are 5 mm (3⁄16 in) long, with a 12 to 22 mm (1⁄2 to 7⁄8 in) wing; they are mostly dispersed by the wind, but some are also dispersed by Clark's nutcrackers.[citation needed]
These ancient trees have a gnarled and stunted appearance, especially those found at high altitudes,[2] and have reddish-brown bark with deep fissures.[6] As the tree ages, much of its vascular cambium layer may die. In very old specimens, often only a narrow strip of living tissue connects the roots to a handful of live branches.[citation needed]
The Great Basin bristlecone pine differs from the Rocky Mountain bristlecone pine in that the needles of the former always have two uninterrupted resin canals, so it lacks the characteristic small white resin flecks appearing on the needles of the latter. The Great Basin bristlecone pine differs from the foxtail pine because the cone bristles of the former are over 2 mm (0.079 in) long, and the cones have a more rounded (not conic) base. The green pine needles give the twisted branches a bottle-brush appearance. The name 'bristlecone pine' refers to the dark purple female cones that bear incurved prickles on their surface.[7]
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Tree in Inyo National Forest
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Young Cone
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Mature Cone
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pollen cones
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New growth
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Bark
Distribution and ecology
The species occurs in
The tree grows in large open stands, unlike the related
Bristlecone pines are protected in a number of areas owned by the United States federal government, such as the Ancient Bristlecone Pine Forest in the White Mountains of California and the Great Basin National Park in Nevada.[7][9] These areas prohibit the cutting or gathering of wood.[9]
Clark's nutcrackers may play a role in seed distribution for P. longaeva, though direct observations of the birds foraging on these seeds have not been reported.[10][11] The nutcrackers use conifer seeds as a food resource, storing many for later use in the ground, and some of these stored seeds are not used and are able to grow into new plants; these trees often exhibit a "multi-trunk" growth form from several seeds germinating at the same time. The prevalence of multi-trunk P. longaeva individuals in areas in which Clark's Nutcrackers are present has been used as evidence that the birds disperse P. longaeva seeds.[11]
An introduced fungal disease known as white pine blister rust (Cronartium ribicola) is believed to affect some individuals. The species was placed on the IUCN Red List and listed as "Vulnerable", or threatened, in 1998.[1] In 2011, however, a population survey found the population of Pinus longaeva to be stable, with no known subpopulations decreasing in size. White pine blister rust was found to have a negligible effect on the population. As a result, the species was moved to "Least Concern".[1]
Fire ecology
The tree is extremely susceptible to fire, and is damaged by even low-intensity burns. The resinous bark is capable of igniting quickly, and a crown fire will almost certainly kill the tree. However, populations of Pinus longaeva are known to be extremely resilient, and as a primary succession species, it is believed that populations of the tree would reestablish itself quickly after a fire. That said, large-scale fires are extremely uncommon where the species grows, and are not a major factor in the species' long-term viability.[2] Historically, Pinus longaeva stands experienced low to high severity fires, and fuels structures changed considerably across elevational gradients. In low elevation, mixed species stands, fuels are often heavy and in close proximity to anthropogenic ignition sources. Yet at high elevations near treeline, Pinus longaeva typically grow on limestone outcroppings that provide little or no surface fuels to propagate a wildfire. However, warmer temperatures will likely increase the duration of fire season, and thus the frequency of fire in Pinus longeava systems at low and mid elevations could increase where stands are typically denser and surface fuel is greatest. While rare, wild fires such as The Carpenter 1 fire in southern Nevada (July 2013) and the Phillips Fire in Great Basin National Park, (September 2000) that started in lower elevation fuel types and moved through the crowns of trees with the aid of extreme fire weather, could become more likely.[12]
Age
A specimen located in the
The confirmed oldest tree of this species, "Methuselah", is also located in the Ancient Bristlecone Pine Forest of the White Mountains. Methuselah is 4,855 years old, as measured by annual ring count on a small core taken with an increment borer. Its exact location is kept secret.[citation needed][15]
Among the White Mountain specimens, the oldest trees are found on north-facing slopes, with an average of 2,000 years, as compared to the 1,000 year average on the southern slopes. The climate and the durability of their wood can preserve them long after death, with dead trees as old as 7,000 years persisting next to live ones.[16]
See also
References
This article incorporates text from the
- ^ . Retrieved 12 November 2021.
- ^ a b c d e f Howard, JL (2004). "Pinus longaeva". Fire Effects Information System. USDA. Archived from the original on 2008-12-18. Retrieved 2008-12-02.
- ISBN 978-1-4027-3875-3.
- ^ a b "Oldlist". Rocky Mountain Tree Ring Research. Archived from the original on 2013-04-12. Retrieved 2013-01-08.
- ^ "Nevada Facts and State Emblems". State of Nevada. Archived from the original on 2014-03-27. Retrieved 2016-02-04.
- ^ "The Gymnosperm Database". March 2008. Archived from the original on 27 June 2011. Retrieved 30 July 2011.
- ^ a b "The Ancient Bristlecone Pine". August 2003. Archived from the original on 6 August 2011. Retrieved 30 July 2011.
- ^ a b Gray, Curtis (2017). Impact of Climate Variability on the Frequency and Severity of Ecological Disturbances in Great Basin Bristlecone Pine Sky Island Ecosystems (Thesis). Utah State University. Archived from the original on 2018-12-07. Retrieved 2018-11-01.
- ^ a b "Global Trees Campaign". March 2008. Archived from the original on 11 July 2011. Retrieved 30 July 2011.
- JSTOR 41712083.
- ^ JSTOR 1551268.
- ISSN 0378-1127.
- ^ Oatman-Stanford, Hunter. "Read My Rings: The Oldest Living Tree Tells All". Collectors Weekly. Archived from the original on 2014-07-29. Retrieved 2014-07-27.
- ^ "RMTRR OLDLIST". www.rmtrr.org. Retrieved 2020-08-22.
- ^ Dr. Peter M. Brown (January 2013). "OldList, a database of ancient trees". Rocky Mountain Tree-Ring Research. Archived from the original on 2013-04-12. Retrieved 2013-01-22.
- ISBN 1-85585-704-9.
- Ewers, F. W.; Schmid, R. (1981). "Longevity of needle fascicles of Pinus longaeva (bristlecone pine) and other North American pines". S2CID 19465953.
- Lewington, A.; Parker, E. (1999). Ancient Trees: Trees that Live for a Thousand Years. London: Collins & Brown Ltd. ISBN 1-85585-704-9.