Abies concolor
Abies concolor, the white fir, is a coniferous tree in the pine family Pinaceae. 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; east through parts of southern Idaho, to Wyoming; 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. White fir live over 300-years and naturally occur at an elevation between 900–3,400 m.
It is popular as an ornamental landscaping tree and as a Christmas tree.
The specific epithet concolor means "all one color".
Description
Size
This large evergreen coniferous tree grows best in the central Sierra Nevada of California, where the record specimen was recorded as 74.9 m tall and measured 4.6 m in diameter at breast height in Yosemite National Park. The typical size of white fir ranges from 25–60 m tall and up to 2.7 m dbh. The largest specimens are found in the central Sierra Nevada, where the largest diameter recorded was found in Sierra National Forest at 58.5 x 8.5 m .Rocky mountain white fir rarely exceed 38 m tall or 0.9 m dbh. Large but not huge trees, in good soil, range from 40 to 60 m tall and from 99 to 165 cm dbh in California and southwestern Oregon and to 41 m tall and 124 cm dbh in Arizona and New Mexico.Leaves and Cones
The leaves are needle-like, flattened, long and wide by thick, green to glaucous blue-green above, 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.The cones are long and 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.
Subspecies
As treated here, there are two subspecies; these are also variously treated at either the lower rank of variety by some authors, or as distinct species by others:''Abies concolor'' subsp. ''concolor''
- Abies concolor subsp. concolor — Colorado white fir or Rocky Mountains white fir. In the United States, at altitudes of in the Rocky Mountains from southern Idaho, south through Utah and Colorado, to New Mexico and Arizona, and on the higher Great Basin mountains of Nevada and extreme southeastern California, and a short distance into northern Sonora, Mexico. A smaller tree to tall, rarely. Foliage strongly upcurved to erect on all except weak shaded shoots in the lower crown; leaves mostly, and strongly glaucous on the upper side with numerous stomata. Tolerates winter temperatures down to about.
''Abies concolor'' subsp. ''lowiana''
- Abies concolor subsp. lowiana — Low's white fir or Sierra Nevada white fir. In the United States, at altitudes of from the Cascades of central Oregon south through California to northern Baja California, Mexico. A larger tree to 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, and only weakly glaucous on the upper side with few or no stomata. Tolerates winter temperatures down to about. The United States Department of Agriculture plants database describes this subspecies as the full species Sierra white fir - Abies lowiana A. Murray bis.
Related species
Forest succession
White fir is a shade tolerant, climax species, which means the forest has reached complex maturity in forest succession in western coniferous forests of the United States. White fir and yellow 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. 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.The white fir trait of retaining lower limbs creates an escape route for medium to small forest birds from larger flying predators and provides a drip zone around the roots for collecting moisture. The retained limbs can become a fire ladder that allow flames to climb up to the canopy. 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. 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.
Botanical Collection
White fir was first collected by Augustus Fendler on his expedition to the Santa Fe area of New Mexico in 1846–1847. Fender's patron George Engelmann, a St. Louis area physician and botanist, then described the plant. 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 1825-27 expedition to the Pacific coast region.Ecology
This tree is host to fir mistletoe, a parasitic plant. It is attacked by many types of insects, such as the fir engraver.Dependent species
Mature white fir–yellow pine forests support old-growth dependent wildlife species such as California spotted owl, Mount Pinos sooty grouse, and Pacific fisher. The spotted owl and fisher utilize cavities in decadent large diameter white fir for nesting and denning. 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. Squirrel also frequent the tree's branches.Deer browse the foliage of this species and porcupines chew the bark. Songbirds, grouse, and various mammals eat the seeds.
Uses
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.White fir 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.