| Abies concolor White fir | |
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| Sierra Nevada white fir inYosemite National Park | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Pinales |
| Family: | Pinaceae |
| Genus: | Abies |
| Species: | A. concolor |
| Binomial name | |
| Abies concolor | |
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| Natural range ofAbies concolor green -A. concolor var.concolor blue -A. concolor var.lowiana | |
| Synonyms[3][4] | |
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Abies concolor, thewhite fir,concolor fir, orColorado fir, is aconiferous tree in the pine familyPinaceae. This tree is native to the mountains of western North America, including theSierra Nevada and southernRocky Mountains, and into theisolated mountain ranges of southernArizona,New Mexico, andNorthern Mexico. It naturally occurs at elevations between 900 and 3,400 metres (3,000 and 11,200 ft).
It is popular as an ornamental landscaping tree and as aChristmas tree.
This large evergreen conifer grows best in the centralSierra Nevada of California, where the record specimen was recorded as 74.9 metres (246 feet) tall and measured 4.6 m (15 ft) indiameter at breast height (dbh) inYosemite National Park.[5] The typical size of white fir ranges from 25–60 m (82–197 ft) tall and up to 2.7 m (8 ft 10 in) dbh. The largest specimens are found in the central Sierra Nevada, where the largest diameter recorded was found inSierra National Forest at 58.5 m × 8.5 m (192 ft × 28 ft) (1972);[5] the west slope of the Sierra Nevada is also home to the tallest specimen on record, 78.8 m (259 ft) in height.[6]Abies concolor subsp.concolor (Rocky mountain white fir) rarely exceeds 38 m (125 ft) tall or 0.9 m (3 ft) dbh. Large (but not huge) trees in good soil range from 40 to 60 m (130 to 200 ft) tall and from 99 to 165 centimetres (39 to 65 in) dbh in California and southwestern Oregon and to 41 m (135 ft) tall and 124 cm (49 in) dbh inArizona and New Mexico.[7] The dead tree tops sometimes fork into new growth.[8]
The gray bark is usually at least 10 cm (4 in) thick, and brown-hued inside.[8] Theleaves are needle-like, flattened, 2.5–8 cm (1–3+1⁄8 in) long and2 millimetres (3⁄32 in) wide by0.5–1 mm (1⁄64–3⁄64 in) thick, green to glaucous blue-green above,[8] and with two glaucous blue-white bands of stomatal bloom below, and slightly notched to bluntly pointed at the tip. The leaf arrangement is spiral on the shoot, but with each leaf variably twisted at the base so they all lie in either two more-or-less flat ranks on either side of the shoot, or upswept across the top of the shoot but not below the shoot.[citation needed]
Thecones are6–12 cm (2+1⁄4–4+3⁄4 in) long and4–4.5 cm (1+5⁄8–1+3⁄4 in) broad, green or purple ripening pale brown, with about 100–150 scales; the scale bracts are short, and hidden in the closed cone. The wingedseeds are released when the cones disintegrate at maturity about 6 months after pollination.[9]
White fir can live over 300 years.[10]
As treated here, there are twosubspecies;[citation needed] these are also variously treated at either the lower rank ofvariety by some authors, or as distinct species by others:
| Image | Name | Description | Distribution |
|---|---|---|---|
 | Abies concolor subsp.concolor —Colorado white fir orRocky Mountain white fir | A smaller tree to 25–35 m (80–115 ft) tall, rarely 45 m (150 ft). Foliage blue-green,[8] strongly upcurved to erect on all except weak, shaded shoots in the lower crown; leaves mostly3.5–6 cm (1+3⁄8–2+3⁄8 in), and strongly glaucous on the upper side with numerousstomata. Tolerates wintertemperatures down to about −40 °C (−40 °F). | In the United States, at altitudes of 1,700–3,400 m (5,600–11,200 ft) in the Rocky Mountains through Utah, Colorado, Arizona, and New Mexico.[8] and on the higherGreat Basin mountains ofNevada and extreme southeastern California, and a short distance into northernSonora, Mexico. |
 | Abies concolor subsp.lowiana (syn.Abies lowiana) —Low's white fir orSierra Nevada white fir | A larger tree growing to 40–60 m (130–195 ft) tall. Foliage flattened on lower crown shoots, the leaves often raised above the shoot on upper crown shoots but not often strongly upcurved; leaves mostly 2.5–5 cm (1–2 in), and only weakly glaucous on the upper side with few or no stomata. Tolerates winter temperatures down to about −30 °C (−22 °F). The United States Department of Agriculture plants database describes this subspecies as the full speciesSierra white fir –Abies lowiana (Gordon & Glend.) A. Murray bis.[11] | In the United States, at altitudes of 900–2,300 m (3,000–7,500 ft)[12] from theCascades ofCentral Oregon south through California (Klamath Mountains, Sierra Nevada) to northern Baja California, Mexico. |
White fir was first collected byAugustus Fendler on his expedition to theSanta Fe area ofNew Mexico in 1846–1847. Fendler's patron George Engelmann, a St. Louis area physician and botanist, then described the plant.[13] This tree was first collected in California byWilliam Lobb on his expedition to California of 1849–1853, after it was overlooked byDavid Douglas in his 1825–1827 expedition to the Pacific coast region.[14][15]
The specific epithetconcolor means "all one color".[16]
This tree is native to the mountains of western North America from the southern Cascade Range inOregon, south throughoutCalifornia and into theSierra de San Pedro Mártir in northernBaja California, and south throughout theColorado Plateau and southernRocky Mountains inUtah andColorado, and into theisolated mountain ranges of southernArizona, New Mexico, andNorthern Mexico. It naturally occurs between 900 and 3,400 m (3,000 and 11,200 ft) above sea level.[10]
White fir is very closely related togrand fir (Abies grandis), and intergrades with it in central Oregon. It is also suggested that all of subspecies lowiana has experienced genetic introgression from grand fir.[17] White fir occupies a different niche than grand fir, including dryer and higher elevation sites, being more drought tolerant and having thicker,fire-resistant bark.[8] In Mexico, it is replaced by further close relatives,Durango fir (A. durangensis) andMexican fir (A. mexicana).[citation needed]
Like grand fir, white fir is moreshade tolerant thanDouglas fir, but less so thanwestern hemlock andwestern redcedar.[8] White fir is aclimax species, which means the forest has reached complex maturity inforest succession in western coniferous forests of the U.S. White fir andyellow pine (ponderosa pine/Jeffrey pine) have co-existed for millennia in old growth forests throughout their range. In the presence of logging of large diameter trees and exclusion of cleansing wildfires, young trees have become abundant over the past two centuries.[18] White fir had been regarded as a pest in the past by those in the lumber industry, but this opinion has changed. White fir is now one of the most important of all commercial softwoods according to the Western Wood Products Association.[19]
The white fir trait of retaining lower limbs creates an escape route for medium-to-small forest birds (such asspotted owl) from larger flying predators and provides a drip zone around the roots for collecting moisture. The retained limbs can become afuel ladder that allows flames to climb up to the canopy.[8] Limbing-up white fir, instead of removing medium to large diameter trees, in areas where the public is more likely to start fires can help keep other trees and specifically giant sequoia from experiencing canopy fire. Recent concern for sequoia groves has caused agencies to call for removal of white fir in the Sierra Nevada. Whilesequoia seedlings and young saplings are highly susceptible to mortality or serious injury by fire; mature sequoias are fire adapted with: fire-resistant bark, elevated canopies, self-pruning lower branches, latent buds, and serotinous cones. The sequoia ecosystem is incomplete without the mixed pine/fir and oak that make up the mid and understory.[20]Giant Sequoia's cones release seeds when the heat of fire triggers them to open while the thick bark protects the innercambium from fire damage.[21]
This tree is host tofir mistletoe (Phoradendron pauciflorum), aparasitic plant. It is attacked by many types of insects, such as thefir engraver (Scolytus ventralis).[22]
Mature white fir–yellow pine forests supportold-growth dependent wildlife species such as Californiaspotted owl (Strix occidentalis occidentalis), Mount Pinossooty grouse (Dendragapus fuliginosus howardi), andPacific fisher (Pekania pennanti). The spotted owl and fisher utilize cavities indecadent large-diameter white fir for nesting and denning.[23] The Mount Pinos sooty grouse requires large diameter trees for thermal cover and its winter diet consists of mostly white fir and yellow pine needles. This subspecies of sooty grouse has been extirpated along with a significant number of large diameter white fir from much of its range. Other subspecies of sooty grouse also utilize Douglas fir, which does not occur in the range of Mount Pinos sooty grouse.[24] Squirrel also frequent the tree's branches.[25]
Deer browse the foliage of this species and porcupines chew the bark. Songbirds, grouse, and various mammals eat the seeds.[25][26]
White fir and grand fir were used by Native Americans for medicinal use involving powdered bark or pitch to treat tuberculosis or skin ailments. TheNlaka'pamux used the bark to cover lodges and make canoes. Branches were also used as bedding.[8]
White fir is a preferred construction species because of its nail-holding ability, lightness in weight, and resistance to split, twist, and pitch. It is straight-grained, non-resinous, fine-textured, stiff, and strong.[27]
It is popular as aChristmas tree and forChristmas decoration owing to its soft needles, generally excellent needle retention and abundance. It is often marketed as concolor or white fir.[28]
White fir is widely planted as anornamental tree in parks and largergardens, particularly somecultivars of subsp.concolor selected for very bright glaucous blue foliage, such as cv. 'Violacea'. The dwarf cultivar 'Compacta', growing to a maximum height and spread of 2.5 m (8.2 ft), has gained theRoyal Horticultural Society'sAward of Garden Merit.[29][30]
Media related toAbies concolor at Wikimedia CommonsAuthority control databases: National |
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