White fir (Abies concolor): what the agencies record

This page reports what US federal publications say about one tree. It does not identify trees from descriptions or photos and does not say what should be done with any tree. The family overview, tree species in the agency records, explains the sources and holds the comparison table.

At a glance

Item	What the source records
Scientific name	Abies concolor (Gord. & Glend.) Lindl. ex Hildebr., pine family; two varieties, var. concolor and var. lowiana
Other names	Rocky Mountain white fir for var. concolor and California white fir for var. lowiana (Silvics)
Native status, USDA PLANTS	Native in the lower 48 states
Size, Silvics	Best development in the central Sierra Nevada of California, where the record specimen is 58.5 m (192 ft) tall and 271 cm (106.6 in) in diameter; large but not exceptional specimens on good sites are 40 to 55 m (131 to 180 ft) tall and 99 to 165 cm (39 to 65 in) across in California and southwestern Oregon, and to 41 m (134 ft) tall and 124 cm (49 in) across in Arizona and New Mexico
Green weight of the wood, NRS-38	47 lb per cubic foot, without bark

Native range and varieties

The Silvics of North America handbook (Agriculture Handbook 654, volume 1, 1990) says the native range of white fir extends from the mountainous regions of the Pacific coast to central Colorado, and from central Oregon and southeastern Idaho to northern Mexico. It separates two varieties because needle form and terpene content vary across the range: the typical variety, often called Rocky Mountain white fir, occupies the eastern and southwestern part of the range, and California white fir grows in the western part. The handbook describes Rocky Mountain white fir as growing on high mountains with long winters, moderate to heavy snowpacks and short growing seasons. It says the species was long considered undesirable for timber, and in 1962 was regarded as undesirable in forests managed for timber, but is recognised as highly productive because it can grow in stands of high basal area.

Cones

Silvics describes white fir as monoecious, with reddish male strobili generally under 1.6 cm (0.6 in) long grouped on the underside of one-year-old twigs about mid-crown, and female cones borne erect on one-year-old branches, usually in the uppermost crown. California white fir flowers in May or June, and Rocky Mountain white fir at higher elevations may flower into July. Female cones reach full size, 7.5 to 13 cm (3 to 5 in) long, in late summer and turn from greenish or purplish to brown when mature, and the seed matures in September, up to 3 weeks before seedfall.

Roots

The handbook says root systems of mature forest trees have not been much studied and what is known comes from observation of windthrown trees. Mature white fir rooting appears fairly adaptable, deep and intensive where soil permits or shallow and widespread where rocks or seasonal water tables limit soil depth, with no strong tendency to keep a single deep taproot, although rapid taproot development is critical for new germinants in the dry summer climate. It says white fir is susceptible to windthrow following partial cutting.

Wood

The Wood Handbook (FPL-GTR-282, 2021) groups white fir with the six commercial western true firs (subalpine fir, California red fir, grand fir, noble fir, Pacific silver fir and white fir), which it says are cut for lumber primarily in Washington, Oregon, California, western Montana and northern Idaho and marketed as white fir throughout the United States. It says it is not possible to distinguish among the true fir species by examining the wood alone, that the woods are light in weight and, apart from subalpine fir, somewhat higher in strength than balsam fir, with low to moderately high shrinkage. The lumber is used primarily for building construction, boxes and crates, planing-mill products, sashes, doors and general millwork, and in house construction for framing, subflooring and sheathing. Silvics calls white fir a general, all-purpose, construction-grade wood used extensively for framing and plywood, and says a significant portion of the Christmas trees used in California are young white fir.

Wood Handbook Table 5-3b	Specific gravity	Modulus of rupture (lbf per square inch)	Side hardness (lbf)
Green	0.37	5,900	340
At 12% moisture content	0.39	9,800	480

The Wood Handbook states that specific gravity is based on oven-dry weight and the volume when green or at 12% moisture content. The green weight of the wood without bark is in the NRS-38 table, the same figure used in the log weight calculator.

Parasites, decay and damage the handbook names

Silvics (1990) names these agents by the names it used.

Mistletoes. Two parasitic plants, white fir mistletoe (a true mistletoe) and white fir dwarf mistletoe, which the handbook says cause major damage. It records white fir mistletoe as a serious problem on large old trees in Arizona, Mexico and the central to southern Sierra Nevada, with heavy infections causing spike tops and loss of vigour, and dwarf mistletoe as a major problem from the southern Sierra Nevada north into Oregon, with one-third of California white fir stands severely infested. Heavily infected trees are described as more prone to bark beetle attack, to a branch-killing Cytospora fungus and to heart rots. The guide mistletoe on the tree covers the mistletoes in general.
Annosus root rot. Heterobasidion annosum, present in all conifer stands, spread through root contacts, with new infection centres beginning from spores landing on basal wounds and freshly cut stumps. The handbook says in true fir it usually does not kill directly but causes moisture stress and loss of vigour that predispose trees to bark beetles such as Scolytus, and heart rot of the butt and major roots leading to windthrow and stem breakage.
Other rots. Yellow cap fungus (a butt rot entering through fire scars and basal wounds), Indian paint fungus (a major heart rot) and white pocket rot (Phellinus pini).
Fire and logging wounds. Saplings and poles are susceptible to fire damage or death and trees become more resistant with age and size. Fire scars in old-growth stands provide an entry for disease and decay organisms. The handbook says studies in Oregon and California found conventional thinning or partial cutting damaged 22 to 50 percent of the residual stand, three-quarters of the wounds at ground level.
Frost, heat and pollution. White fir is sensitive to spring and fall frosts, which kill developing buds and foliage, and frost cracks and ring shake are associated with some rot. It is rated moderately susceptible to ozone damage and more resistant to fluoride damage than Douglas-fir or ponderosa pine.

The guide on reporting a pest in the United States and the Canada reporting page give the offices that take sightings of regulated pests. Who may apply pesticides is in pesticide licences by country.