Abies bracteata description

Cone of an old tree (2).

Cone and cone scale [L.A. Vorobik] (8).

Abies bracteata D. Don ex Poiteau 1845

Common Names

Santa Lucia, bristlecone, or silver fir; fringed spruce (4).

Taxonomic notes

Syn: A. religiosa sensu Hook. et Arn. 1833, A. venusta Douglas 1836, Pinus bracteata D. Don 1836, Picea bracteata (D. Don) Loud. 1838, A. bracteata (D. Don ) Hook. et Arn. 1841, Taxodium sempervirens Hook. et Arn. 1841, A. bracteata (D. Don) Nuttall 1849, Sequoia religiosa (Hook. et Arn.) Presl 1851 A. venusta (Douglas) K. Koch 1873 (4).

Description

A narrowly conical tree 12-30 m tall, 10-30(100) cm dbh, with a spire-like crown and with short, slightly drooping branchlets. Bark light red-brown, thin, smooth, with age becoming slightly fissured and broken into appressed scales. Branches diverging from trunk at right angles, the lower often drooping in age. Twigs smooth to somewhat pubescent, shiny light reddish-brown, purplish green or brown. Buds exposed, ovate to fusiform, pale yellowish-brown, sharp-pointed, 10-20 mm long, not resinous, apex pointed; basal scales short, broad, equilaterally triangular, glabrous, not resinous, margins entire, apex sharp-pointed. Needles 2-ranked to spiraled, flattened, stiff, with raised abaxial vein, pointing forwards, distinctly parted, shiny dark green above, (25)35-55(60)mm long by 2.5-3 mm wide, with 2 broad white bands below with with 8-10 stomatal rows on each side of midrib; odor pungent; base twisted; apex long-spined; cross section flat-convex; resin canals small, near margins and abaxial epidermal layer. Staminate cones at pollination pale yellow to yellow-green, 5-7 cm long by 2-3 cm wide. Ovulate cone ovoid, resinous, (6)7-10(14) cm long by 4-5.5cm wide, violet-brown to purple-brown, borne on stout peduncles; scales ca. 1.5-2 × 2-2.5 cm, glabrous, thin, rounded, finely serrulate; bracts long exserted, not reflexed, trilobed, yellowish-brown, extending 4-5 cm beyond the scales, resinous. Seeds shiny, deep red-brown, 5 mm long, wing 8-11 mm long; cotyledons ca. 7 (1, 7). Flowers bloom in early May, cones mature and disperse seed from late August to October (4).

Range

US: California: Santa Lucia Mountains. This area is a narrow coastal strip in the Los Padres National Forest (3). Climate is Mediterreanean with about 500-1300 mm annual precipitation. Found in moist canyon bottoms and rocky slopes where fuel accumulations do not permit fire. Latitude range is entirely between 36 and 37°N, and altitude varies from 600 to 914 m (atop Cone Peak) (4). Called the rarest fir in the world (5). See also (9).

Big Tree

No official champion as of 1996. Heights to 50 m and dbh to 100 cm (4).

Oldest

Dendrochronology

Ethnobotany

Aromatic resin was used as incense in the early Spanish mission nearby (3).

Observations

I have seen it in its home range, on Cone Peak near the southern end of the Santa Lucia Mountains. This site was formerly accessible by road, but now requires several miles of walking (or a mountain bike). Maps and directions are available from Los Padres National Forest. A popular ornamental, it can be seen in many arboreta.

Remarks

First found by Thomas Coulter in 1831 and afterwards collected by Douglas, Hartweg, and others. One of the handsomest trees in the genus. Common associates are Pinus coulteri, P. ponderosa, Pseudotsuga menziesii, and Quercus chrysolepis (4).

The following paragraphs are quoted verbatim from (7).

"Santa Lucia fir, Abies bracteata, is the rarest fir in the world, being endemic to California's Santa Lucia Mountains. Within these mountains it occurs in scattered groves ranging in elevation from 600 to 5150 feet, with most stands on north- and northeast-facing slopes. Above 4500 feet individuals will occasionally be found on south- and southeast-facing slopes; these trees can always be traced to relatively moist, sheltered microsites. Stands below 1700 feet are rare and are always at the bottom of a large canyon, where cold air drainage is important. The lowest stand ranges between 600 and 900 feet at Ventana Camp on the Big Sur River. This location lies at the bottom of a 300-foot-deep canyon, in the redwood belt, and is freqently foggy. These data suggest low water potentials [I suspect he means low in absolute value] as an important limiting factor in the trees' distribution. Site index of mature fir, needle dimensions, and seed and cone size all point toward this conclusion. There are no successful records of introduction for the eastern United States, while numerous groves thrive in Europe. This suggests that Santa Lucia fir may also require equable temperatures. Further evidence of a requirement for equable temperature can be seen in needle dimensions (relation of length to width), but this is still speculative. The role of water potential and temperature upon the growth and development of Santa Lucia fir is now being examined more closely in both the field (for mature trees and first season seedlings) and in the controlled environments of the Phytotron at Duke University.

"The widely scattered nature of fir groves within the Santa Lucia Mountains is primarily due to theis tree's susceptibility to fire injury, although competition with other vegetation and aspect are also important. Large stands of fir are always in regions of precipitous cliffs or steep-rugged canyons which are steep enough to prevent litter accumulation extensive enough to carry a strong fire. This also provides a mineral soil surface for germinating seed. Both influences are considered important. The Buckeye Canyon fire of Sep 1970 presented a vivid example of how this tree is restricted by fire. This fire was one of the hottest, certainly the largest, of several decades. Whole slopes were completely"cleaned off", while the two fir stands in the burn received only ground fires, or didn't burn at all. Santa Lucia fir not only appears to be restricted to generally fireproof topography, but may even be restricted to regions where the topography makes it impossible for a fire to enter a grove going uphill.

"There has been speculation that either fire or insects will eliminate this tree in the near future. While fire has certainly reduced the fir's potential range within the Santa Lucia Mountains, and two species of seed calcid (Megestigans (?)) normally inflict 100% mortality on the annual seed crop, and a green larva (probably a moth) severely defoliates the young shoots, the fir does not appear to be in any immediate danger of either extinction or further range restriction. Good seed crops are occasionally produced by the fir's ability to repond to climatic fluctuations with a dramatic fluctuation in annual cone production, thus literally swamping the wasps with more seed than they can parasitize in one year, and producing next to no cones the subsequent year. Quantitative data for this phenomenon are still being analyzed but tentative conclusions point directly for an interaction of climate and past cone production leading to cone production on much the same basis as wide versus narrow rings are produced in trees of semi-arid climates. As for the green larvae which defoliate both young and mature trees, the larvae will simply have to be raised and the life cycle reconstructed. As for the score of wood boring beetles that attack fir trunks and branches, their total impact is not alarming, and, like the other insects, appears to represent a stable equilibrium.

"For a fir, this tree has many unusual characters: large sharply tipped "xeromorphic" needles, thin bark (leading to fire susceptibility), persistent lower branches (even when trees are 4 feet DBH and 150 feet tall), an Indian club shaped crown, non-resinous buds and, of course, protruding cone scale bracts. These bracts have been found to merge imperceptibly into normal needles in mutant cones of one tree sampled in Tilden Regional Park, Oakland, 1971. However, the chromosome number is 24 like the rest of the Pinaceae except Pseudotsuga, and the karyotype is distinctly that of an Abies. The conclusion that this tree is a"strange" fir thus appears correct.

"Santa Lucia fir may also be resistant to air pollution as the Tilden Park grove is thriving, as are trees in San Francisco and Europe. With most of the range in the Los Padres National Forest (Monterey unit) and on the Heart Ranch there seems to be little daanger of this tree's habitat being disturbed. The only use the tree may find outside of watershed control and contributing to the beauty of the Santa Lucia Mountains is as an ornamental. With the Tilden Park grove now producing an abundance of pest-free seed more and more of these beautiful trees should be planted.

"There has been considerable conjecture as to this tree once having a wider range. The fossil record attributed to this tree in the past, however, is a series of misidentifications, and no sound evidence exists for this tree in any fossil flora, excepting one possible needle and seed from western Nevada, and this is still under study by Dr. Axelrod at U.C. Davis. We have no idea as to when the fir arrived in the Santa Lucia Mountains or where it came from. As to why it is not found elsewhere in the West today we can ask ourselves: Where else can high equability, heavy winter rains with long dry summers, and large areas of fireproof topography be found. The answer is nowhere but the Santa Lucia Mountains for all of western North America" (7).

Citations

(1) Silba 1986.

(2) van Gelderen et al. 1986.

(3) Little 1980.

(4) Liu 1971.

(5) Peattie 1950 (as A. venusta).

(6) Hunt, Richard S. at the Flora of North America web site.

(7) Talley, Steven N. 8 Jun 1972. Notes concerning the status of ecological studies on Santa Lucia fir, Abies bracteata. Not known to have been published; manuscript acquired in 1989 from a Los Padres NF district ranger office.

(8) Hickman 1993.

(9) Robert S. Thompson, Katherine H. Anderson and Patrick J. Bartlein. 1999. Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America. U.S. Geological Survey Professional Paper 1650 A&B. URL= http://greenwood.cr.usgs.gov/pub/ppapers/p1650-a/pages/conifers.html.