Abies concolor

Abies concolor, the white fir, concolor fir, or Colorado fir, is a coniferous tree in the pine family Pinaceae. This tree is native to the mountains of western North America, including the Sierra Nevada and southern Rocky Mountains, and into the isolated mountain ranges of southern Arizona, New Mexico, and Northern Mexico. It naturally occurs at elevations between Template:Convert.

It is popular as an ornamental landscaping tree and as a Christmas tree.

Description

This large evergreen conifer grows best in the central Sierra Nevada of California, where the record specimen was recorded as Template:Convert tall and measured Template:Convert in diameter at breast height (dbh) in Yosemite National Park.<ref name="AmericanForestryAssociation1978">American Forestry Association. 1978. National register of big trees. American Forests 84(4):19-47</ref> The typical size of white fir ranges from Template:Convert tall and up to Template:Convert dbh. The largest specimens are found in the central Sierra Nevada, where the largest diameter recorded was found in Sierra National Forest at Template:Convert (1972);<ref name="AmericanForestryAssociation1978" /> the west slope of the Sierra Nevada is also home to the tallest specimen on record, Template:Convert in height.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Abies concolor subsp. concolor (Rocky mountain white fir) rarely exceeds Template:Convert tall or Template:Convert dbh. Large (but not huge) trees in good soil range from Template:Convert tall and from Template:Convert dbh in California and southwestern Oregon and to Template:Convert tall and Template:Convert dbh in Arizona and New Mexico.<ref>Jones, John R. 1974. Silviculture of southwestern mixed conifers and aspen: the status of our knowledge. USDA Forest Service, Research Paper RM-122. Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 44 p.</ref> The dead tree tops sometimes fork into new growth.<ref name="Arno-2020" />

The gray bark is usually at least Template:Convert thick, and brown-hued inside.<ref name="Arno-2020">Template:Cite book</ref> The leaves are needle-like, flattened, Template:Convert long and Template:Convert wide by Template:Convert thick, green to glaucous blue-green above,<ref name="Arno-2020" /> 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.Template:Citation needed

The cones are Template:Convert long and Template:Convert broad, green or purple ripening pale brown, with about 100–150 scales; the scale bracts are short, and hidden in the closed cone. The winged seeds are released when the cones disintegrate at maturity about 6 months after pollination.<ref>Template:EFloras</ref>

White fir can live over 300 years.<ref name="USDA-2016">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Subspecies

As treated here, there are two subspecies;Template:Citation needed these are also variously treated at either the lower rank of variety by some authors, or as distinct species by others:

Image	Name	Description	Distribution
File:Abies concolor cones.jpg	Abies concolor subsp. concolor — Colorado white fir or Rocky Mountain white fir	A smaller tree to Template:Convert tall, rarely Template:Convert. Foliage blue-green,<ref name="Arno-2020" /> strongly upcurved to erect on all except weak, shaded shoots in the lower crown; leaves mostly Template:Convert, and strongly glaucous on the upper side with numerous stomata. Tolerates winter temperatures down to about Template:Convert.	In the United States, at altitudes of Template:Convert in the Rocky Mountains through Utah, Colorado, Arizona, and New Mexico.<ref name="Arno-2020" /> and on the higher Great Basin mountains of Nevada and extreme southeastern California, and a short distance into northern Sonora, Mexico.
File:Abies concolor 8065.jpg	Abies concolor subsp. lowiana (syn. Abies lowiana) — Low's white fir or Sierra Nevada white fir	A larger tree growing to Template:Convert 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 Template:Convert, and only weakly glaucous on the upper side with few or no stomata. Tolerates winter temperatures down to about Template:Convert. The United States Department of Agriculture plants database describes this subspecies as the full species Sierra white fir – Abies lowiana (Gordon & Glend.) A. Murray bis.<ref>Template:PLANTS</ref>	In the United States, at altitudes of Template:Convert<ref>Template:EFloras</ref> from the Cascades of Central Oregon south through California (Klamath Mountains, Sierra Nevada) to northern Baja California, Mexico.

Botanical collection

White fir was first collected by Augustus Fendler on his expedition to the Santa Fe area of New Mexico in 1846–1847. Fendler's patron George Engelmann, a St. Louis area physician and botanist, then described the plant.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> This tree was first collected in California by William Lobb on his expedition to California of 1849–1853, after it was overlooked by David Douglas in his 1825–1827 expedition to the Pacific coast region.<ref>Template:Cite book</ref><ref>Gordon, George, & Glendinning, Robert. Pinetum 155. 1858.</ref>

The specific epithet concolor means "all one color".<ref name="RHSLG">Template:Cite book</ref>

Distribution

This tree is native to the mountains of western North America from the southern Cascade Range in Oregon, south throughout California and into the Sierra de San Pedro Mártir in northern Baja California, and south throughout the Colorado Plateau and southern Rocky Mountains in Utah and Colorado, and into the isolated mountain ranges of southern Arizona, New Mexico, and Northern Mexico. It naturally occurs between Template:Convert above sea level.<ref name="USDA-2016" />

Ecology

White fir is very closely related to grand 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.<ref>Template:Cite journal</ref> 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.<ref name="Arno-2020" /> In Mexico, it is replaced by further close relatives, Durango fir (A. durangensis) and Mexican fir (A. mexicana).Template:Citation needed

Like grand fir, white fir is more shade tolerant than Douglas fir, but less so than western hemlock and western redcedar.<ref name="Arno-2020" /> White fir is a climax species, which means the forest has reached complex maturity in forest succession in western coniferous forests of the U.S. White fir and yellow 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.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> 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.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

The white fir trait of retaining lower limbs creates an escape route for medium-to-small forest birds (such as spotted owl) from larger flying predators and provides a drip zone around the roots for collecting moisture. The retained limbs can become a fuel ladder that allows flames to climb up to the canopy.<ref name="Arno-2020" /> 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. While sequoia 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.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Giant Sequoia's cones release seeds when the heat of fire triggers them to open while the thick bark protects the inner cambium from fire damage.<ref>The Giant Sequoia of the Sierra Nevada</ref>

This tree is host to fir mistletoe (Phoradendron pauciflorum), a parasitic plant. It is attacked by many types of insects, such as the fir engraver (Scolytus ventralis).<ref>Maloney P. E. & D. M. Rizzo. (2002). Pathogens and insects in a pristine forest ecosystem: the Sierra San Pedro Martir, Baja, Mexico. Canadian Journal of Forest Research 32:3 448-57.</ref>

Dependent species

Mature white fir–yellow pine forests support old-growth dependent wildlife species such as California spotted owl (Strix occidentalis occidentalis), Mount Pinos sooty grouse (Dendragapus fuliginosus howardi), and Pacific fisher (Pekania pennanti). The spotted owl and fisher utilize cavities in decadent large-diameter white fir for nesting and denning.<ref>Template:Cite journal</ref> 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.<ref>Template:Cite journal</ref> Squirrel also frequent the tree's branches.<ref name=Peattie>Template:Cite book</ref>

Deer browse the foliage of this species and porcupines chew the bark. Songbirds, grouse, and various mammals eat the seeds.<ref name=Peattie/><ref>Template:Cite book</ref>

Uses

White fir and grand fir were used by Native Americans for medicinal use involving powdered bark or pitch to treat tuberculosis or skin ailments. The Nlaka'pamux used the bark to cover lodges and make canoes. Branches were also used as bedding.<ref name="Arno-2020" />

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.<ref>Western Wood Products Association (WWPA)</ref>

It is popular as a Christmas tree and for Christmas decoration owing to its soft needles, generally excellent needle retention and abundance. It is often marketed as concolor or white fir.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Cultivation

White fir is widely planted as an ornamental tree in parks and larger gardens, particularly some cultivars 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 Template:Convert, has gained the Royal Horticultural Society's Award of Garden Merit.<ref name = RHSPF>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Gallery

• Abies concolor 8076.jpg

  A. concolor subsp. lowiana foliage upperside

• Abies concolor 8065.jpg

  A. concolor subsp. lowiana foliage underside

• Baby whitefir.jpg

  A young sapling of subsp. lowiana on Mount Whitney

• White fir MN 2007.JPG

  White fir in garden environment at Minnesota Landscape Arboretum

• Young Abies concolor.jpg

  Small stand of young white firs on Cuyamaca Peak, California

• Toro Peak 537.jpg

  White firs at Toro Peak, California

• Arceuthobium abietinum 1.jpg

  Foliage, with Arceuthobium abietinum infestation

Further reading

• Template:Cite book
• Template:Silvics

External links

• Template:Commons category-inline
• Jepson eFlora Treatment - Abies concolor
• Gymnosperm Database: Abies concolor — (treated as varieties of one species).
• Interactive Distribution Map of Abies concolor
• USDA Plants Profile for Abies concolor (white fir)
• Conifers Around the World: Abies concolor - Rocky Mountain White Fir.
• Conifer Database