Faul Preserve | Abies concolor | white fir

Botanical Family: Pinaceae

Scientific Name: Abies concolor

Common Names: white fir

Botanical Description:

Abies concolor is a large, narrowly pyramidal (or conical), symmetrical (when young), evergreen conifer, typically growing 10 to 40 meters tall, and becoming more irregularly shaped and rounded with age (1,2). The branches grow perpendicular to the trunk, with lower branches tending to droop downwards, although the lower half of the trunk is often bare in crowded forest areas (1,2). The bark is white to gray, thin and smooth, becoming thicker, darker in color, and breaking into deep longitudinal furrows with age (1,3). The furrows sometimes reveal the slightly yellow, corky, inner layer of the periderm (1,3). Young branches tend to be glabrous, but occasionally exhibit yellowish pubescence (1). The leaves are flattened needles which are flexible, 2-3 inches long, silvery, gray blue to green in color, and often 2-ranked (appearing on opposite sides of the stem) (1,2,3). White fir is monoecious, with 6-9 mm long pollen-bearing cones (strobili) that are dark red or yellow in color, appearing in dense clusters on the undersides of 1-year old twigs around the mid-crown, and seed-bearing cones that are 7-12 cm long, broadly winged, cylindrical, yellow green at first, becoming brown or purplish at maturity, and appearing on 1-year old branches at the uppermost sections of the crown (1,4,5). White fir trees begin producing cones at about 40 years of age, the cones emerging mid-spring to early summer, from April to June, with the seeds maturing in September (2,4,5).

Ecological Significance:

Abies concolor is widespread in mountain ranges across western North America, with communities occupying a broad range of elevations, from 3,000 to 12,000 feet depending on the climate and region (1,5). In Arizona, white fir typically occurs from 5,500 to 9,000 feet, with communities in the mountains of southern Arizona occurring at the highest elevations (1,5). Abies concolor prefers semi-arid climates, and it tolerates a wide range of soil conditions, with growth and development positively affected on deep and well-draining sandy-loam to clay-loam soil types (5). White fir is a climax species; it steadily gains dominance as succession occurs in mixed conifer-deciduous forests (5). Shade is needed for survival of seedlings, with the young trees being susceptible to drought, sun scald, and heat (5). Some plants that typically grow in association with white fir, such as snowbush ceanothus and bracken fern, produce allelopathic chemicals in their foliage that suppresses radicle (embryonic root) growth in white firs, but it is thought that mycorrhizal associations can protect the roots of white fir from the effects of these chemicals (5). Abies concolor is a source of food, cover and nesting sites for various mammals, birds, and even some reptiles (1,5). In the southwest, the foliage is grazed by bighorn sheep and deer, while the bark is gnawed by porcupines (1,2,5). White fir provides habitat for the likes of black bears, mountain lions, deer, elk, river otters, Arizona gray squirrels, bald eagles, Mexican spotted owls, goshawks, zone-tailed hawk, common black hawk, tanagers, dippers, orioles, warblers, woodpeckers, Arizona alligator lizards, and Sonoran mud turtles (5). The critically endangered, thick-billed parrot utilizes conifers such as white fir, and pine (Pinus spp.) for nesting, and food; it is the only surviving parrot species native to North America, however, attempts to reintroduce the thick-billed parrot to the mountains of southeastern Arizona have been so far unsuccessful (5,6).

Ethnobotanical Value: 

Abies concolor is valued as an ornamental tree for its beauty, and frost tolerance and it is grown commercially for use as a Christmas tree (1,5). The wood is used for fuel, lumber, and paper pulp (1,2,5). The Hopi consider white fir important for various medicinal purposes (1). The pitch has been used for its antiseptic properties, to create a poultice for cuts and wounds, and as an infusion with the bark to treat Tuberculosis (7). Infusions of foliage in a bath have been used to relieve rheumatism (7). The resin has also been used to treat venereal disease (1). Decoctions of needles and bark resin have been used to treat pulmonary issues (1,7).

Distribution:

Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon, Utah, Wyoming, and Mexico

Photos (click for attribution):

Branches | Bark | Needles | Seed Cones