Abies lasiocarpa

Subalpine Fir (Abies lasiocarpa )

The Subalpine Fir or rock - fir ( Abies lasiocarpa ) is a coniferous tree from the kind of fir (Abies ). The home of this type lies in the western North America, where it occurs from Arizona north to the tree line Südalaskas.

• 6.1 Notes and references

Description

Habit and foliage

The Subalpine Fir is an evergreen tree. You can plant height to good 20 meters, rarely reach even 40 to 50 meters; the trunk diameter can reach up to 1 meter, exceptionally up to 2 meters ( BHD). Often, however, the conifer grows well as a broad shrub. Looking at the average height, so it is the smallest of the eight native to the western U.S. pine species.

Due to the adaptation to the different environmental conditions of the natural habitats five growth forms can be distinguished:

• Very narrow cone-shaped, upright habit with short, stiff branches. This is the typical form in most deposits in the subalpine zone. Trees in the open state retain their lower branches, which often bend at the age down to the ground. Sealing standing trees are knotless to about quarter of the total height.
• A wider, rounded treetop can be found in old copies dryer locations.
• Full-grown trees that form a ground- mat, are rarely encountered in some areas.
• At high altitudes near the tree line there is often a flag -like crown structure. An upright stem protrudes beyond a krummholz -like mat that spreads to the leeward side.
• Above the tree line the curved wood is the typical growth form. Due to the cold temperatures and harsh winds the Subalpine fir grows here in miniature form ground-level mats and is often much wider than high.

The first of typical form with conical crown usually reaches heights of growth between 18 and 30 meters and trunk diameter of 46-61 centimeters. Larger specimens are rare.

The Subalpine Fir grows slowly; Specimens between 150 and 200 years of age usually have only 25 to 50 inches trunk diameter. The trees are rarely older than about 250 years, as they are very susceptible to stem rot caused by fungal infestation.

The Subalpine fir is predominantly a shallow roots; However, depending on the terrain they can also root deeper.

The bark of young trees is gray and smooth with resin blisters. On old trees the bark is rough and furrowed or scaly. In the cork tree, the variety arizonica, the bark of which is deviating off-white, thick and corky. The bark of the stiff twigs are greenish gray to light brown and only slightly hairy brownish. The buds are hidden partly under the needle dress. The small, almost spherical buds are tan to dark brown and resinous. The basal bud scales are triangular to spatulate.

The needle-like leaves are flat, 1.5 to 3 inches long and 1.25 to 2 millimeters wide; they end blunt. In cross-section, the needles are flat with a notch on the upper side. They are shiny green on top with a wide Stomastreifen, under hand, they have two bluish-white Stomastreifen on. The needles are spirally around the twig, but the leaf bases arise while predominantly the side of the branch. The needles are seated tightly and are part of each other. Fresh leaf scars show a reddish periderm. Grated needles give off a pungent odor by β - Phellandrene.

Flowers, cones, Other

The Subalpine fir is monoecious. The cone production begins approximately after 20 years in the cork pine (variety arizonica ) only after about 50 years.

The male cones are tightly clustered in the lower part of the tree crown on the underside of one-year branches. You are to maturity purple to purple - greenish.

The female cones are available individually or in smaller groups in the upper part of the tree crown. They are cylindrical in shape with a rounded tip, 6-12 cm long and 2-4 inches wide. They are dark colored purple; the 1.5 to 2.5 cm long bracts are densely hairy yellow-brown. The cones stand upright on the branch (as with all pines ). When ripe in early autumn they turn brown; by the scales fall from the spindle, the winged seeds are released. The seeds are 6-7 mm long, 2-3 mm thick and brown; they wear a light brown, about an inch long wings. The seeds of the cork pine (variety arizonica ) point notwithstanding, the 1.7 times life size.

The number of cotyledons ( cotyledons ) can vary from 3 to 6; there are usually 4 or 5, the chromosome number is 2n = 24

Distinguish the varieties

Southeast of the natural range, the nominate form is partly due to their variety Abies lasiocarpa var arizonica replaced. This has a corky, thick and bright blue-gray bark and needles.

The variety bifolia differs from the nominate form in chemical wood properties, the lack of crystals in certain parenchyma, lack of Lasiocarpenonol and in the different composition of terpenes. Also, other features such as the color of the periderm and the shape of the basal bud scales are different. Fresh leaf scars show a yellow to lohbarbenes periderm ( at lasiocarpa is reddish). The basal bud scales are narrow - triangular to spatulate ( at lasiocarpa they are equilateral triangular). Grated leaves smell slightly camphor ( at lasiocarpa: pungent odor by β - Phellandrene ). The needles are 11 to 25 millimeters in length and 1.25 to 1.5 millimeter width smaller than lasiocarpa with 18 to 31 millimeters in length and 1.5 to 2 millimeters wide.

The delineation of the variety arizonica occurs most clearly about her rather off-white, thick korkige bark that is furrowed dark gray and deep. Their foliage is bluer and brighter than the nominate lasiocarpa.

Between the type and the variety bifolia takes place in central British Columbia and northern Washington introgression. In north central Alberta (Abies balsamea ) is observed introgression of the variety bifolia with the balsam fir. The nominate lasiocarpa hybridized probably in the southern part of its range with Abies procera. Hybridization with the purple - fir ( Abies amabilis ), however, apparently does not take place in spite of a large common area of ​​distribution.

Distribution and location

The entire area of ​​distribution extends from southern Alaska through Canada ( Yukon, Northwest Territories, British Columbia and Alberta) in the U.S. states of Washington, Oregon, California, Idaho, Montana, Wyoming, Colorado, New Mexico, Arizona, Utah and Nevada. Thus, it is in North America, of fir with the broadest distribution in north-south direction.

The nominate Abies lasiocarpa var lasiocarpa is native to southern Alaska, Yukon, British Columbia and Alberta and is spread even further south in the Rocky Mountains and the Cascade Mountains and the Olympic Mountains in Washington before. The deposits are located mainly at altitudes 1100-2300 m in subalpine coniferous forests near the coast; at most of their locations they encountered at altitude prior to the tree line. Often it is with Abies amabilis, Pinus albicaulisund Tsuga mertensiana socialized.

The variety Abies lasiocarpa var arizonica is native to the southern Rocky Mountains in the U.S. states of Arizona, Colorado and New Mexico. They inhabited altitudes 2400-3400 m and is associated engelmannii in many parts of its range with Picea.

The occurrence of the variety Abies lasiocarpa var bifolia extend from the southern Yukon, the Northwest Territories, Alberta and British Columbia in Canada south in the U.S. states of Washington, Oregon, Idaho, Montana, Wyoming, Colorado, New Mexico, Arizona, Utah and Nevada. They inhabited altitudes 600-3700 m in subalpine coniferous forests. Similar to the nominate form also meets this variety in the majority of their locations before up to the tree line. In many areas it is associated with Picea engelmannii.

System

The Subalpine fir is classified within the genus of fir (Abies ) in the sub-section within the Lateral section Balsamea.

The description under the taxon Pinus lasiocarpa by the British botanist William Jackson Hooker goes back to the year 1839. The English botanist Thomas Nuttall ordered the species under the taxon Abies lasiocarpa in the genus Abies one; this currently valid description was published in 1849.

It can be distinguished in addition to the nominate two varieties; in part, the variety is bifolia also as a separate species Abies bifolia viewed:

• Abies lasiocarpa var arizonica ( Merriam ) Lemmon (also called cork - fir)
• Abies lasiocarpa var bifolia (A. Murray ) Eckenw.
• Abies lasiocarpa var lasiocarpa

The description of the variety arizonica by John Gill Lemmon was published in 1898; this was based on the published description in 1896 by Clinton Hart Merriam under the taxon Abies arizonica.

A synonym for the nominate form is Pinus lasiocarpa Hooker 1838; for the variety bifolia Abies Subalpina Engelmann is a synonym.

Use

The tree is sometimes planted as an ornamental because of its bluish foliage tree and cultivated as a Christmas tree.

The wood of the Subalpine fir is of low density, soft, odorless and easy to work with. It is used for paper manufacturing or as a timber. The wood is not weather resistant.

Threats and conservation

The Subalpine Fir is " not threatened " on the Red List of IUCN. It is noted, however, that a re-evaluation of risks is required.

Swell

• Christopher J. Earle: Abies lasiocarpa. In: The Gymnosperm Database. Accessed on 2 February 2011 ( English).
• Richard S. Hunt: Abies lasiocarpa. In: Flora of North America Editorial Committee ( eds.): Flora of North America North of Mexico. Volume 2: pteridophytes and Gymnosperms, Oxford University Press, New York / Oxford et al, 1993, ISBN 0-19-508242-7.
• Richard S. Hunt: Abies bifolia. In: Flora of North America Editorial Committee ( eds.): Flora of North America North of Mexico. Volume 2: pteridophytes and Gymnosperms, Oxford University Press, New York / Oxford et al, 1993, ISBN 0-19-508242-7.
• Ronald J. Uchytil: Abies lasiocarpa. In: Fire Effects Information System. U.S. Department of Agriculture, accessed 2 February 2011 (English).