Giant Fir

Foodplant / false gall
Adelges piceae causes swelling of live, sometimes swollen branch of Abies grandis

Foodplant / saprobe
fruitbody of Exidiopsis grisea is saprobic on dead, decayed bark of Abies grandis
Other: major host/prey

Foodplant / parasite
hypophyllous, two irregular rows aecium of Milesina kriegeriana parasitises locally yellowed needle of Abies grandis
Remarks: season: 6-9

Foodplant / parasite
hypophyllous, in two rows aecium of Pucciniastrum epilobii parasitises needle of Abies grandis
Remarks: season: 6-7

In Great Britain and/or Ireland:
Foodplant / parasite
densely gregarious, linearly arranged, hypophyllous pycnidium of Rhizosphaera coelomycetous anamorph of Rhizosphaera pini parasitises live needle of Abies grandis
Remarks: season: 2

Foodplant / saprobe
effuse colony of Thysanophora dematiaceous anamorph of Thysanophora penicillioides is saprobic on dead, rotting, fallen needle of Abies grandis

Abies grandis is rather uniform morphologically and chemically. At its southern limit in southern Oregon and northern California, it introgresses with A . concolor (J.L. Hamrick and W.J. Libby 1972; E.Zavarin et al. 1975; D.B. Zobel 1973). In the area of introgression, specimens in lower, wetter habitats are best assigned to A . grandis ; those in higher, drier habitats, to A . concolor . Others are best considered to be A . concolor ´ grandis .

Trees to 75m; trunk to 1.55m diam.; crown conic, in age round topped or straggly. Bark gray, thin to thick, with age becoming brown, often with reddish periderm visible in furrows bounded by hard flat ridges. Branches spreading, drooping; twigs mostly opposite, light brown, pubescent. Buds exposed, purple, green, or brown, globose, small to moderately large, resinous, apex round; basal scales short, broad, equilaterally triangular, slightly pubescent or glabrous, resinous, margins entire, apex pointed or slightly rounded. Leaves (1--)2--6cm ´ l.5--2.5mm, 2-ranked, flexible, with leaves at center of branch segment longer than those near ends, or with distinct long and short leaves intermixed, proximal portion ± straight, leaves higher in tree spiraled and 1-ranked; cross section flat, grooved adaxially; odor pungent, faintly turpentinelike; abaxial surface with 5--7 stomatal rows on each side of midrib; adaxial surface light to dark lustrous green, lacking stomates or with a few stomates toward leaf apex; apex distinctly notched (rarely rounded); resin canals small, near margins and abaxial epidermal layer. Pollen cones at pollination bluish red, purple, orange, yellow, or ± green. Seed cones cylindric, (5--)6--7(--12) ´ 3--3.5cm, light green, dark blue, deep purple, or gray, sessile, apex rounded; scales ca. 2--2.5 ´ 2--2.5cm, densely pubescent; bracts included. Seeds 6--8 ´ 3--4mm, body tan; wing about 1.5 times as long as body, tan with rosy tinge; cotyledons (4--)5--6(--7). 2 n =24.

Moist, coastal coniferous forests and mountain slopes; 0--1500m; B.C.; Calif., Idaho, Mont., Oreg., Wash.

Pinus grandis Douglas ex D. Don in Lambert, Descr. Pinus [ed. 3] 2: unnumbered page between 144 and 145. 1832

Because grand fir wood does not contain decay-inhibiting properties nor exude pitch over wounds, trees that survive fire are susceptible to the entry of decay fungi through fire scars and stimulation of dormant decay by fire injury. The problem is more serious east of the Cascade Range crest because of the ubiquitousness of Indian paint fungus in the eastern portion of grand fir's range. [7,8,9,14,16,108,62].

More info for the terms: forest, low-severity fire, wildfire

In northeastern Oregon, 3 wildfire sites were selected to study fire's effects on late-seral grand fir/big huckleberry associations. Two sites were severely burned, and 1 site was lightly underburned. The severe fires killed all overstory and understory grand fir. The low-severity fire was continuous with fire scorching only the basal portion of the large-diameter (30-40 inch (76-102 cm)) trees. The low-severity fire reduced overstory grand fir coverage from 55 to 40%, and the understory was reduced from 10 to 5%. A thicket of grand fir saplings was reduced by 30% [109].

Fire may aid grand fir regeneration on most sites, but grand fir may regenerate poorly after fire on south-facing slopes or on dry sites [58,98]. In a grand fir/pachistima habitat in the Coeur d'Alene River drainage of northern Idaho, grand fir established readily on unburned sites following clearcutting, but required shade for regeneration on clearcut and burned sites [195].

A prescribed stand-replacment fire in a mixed lodgepole pine-subalpine fir-grand fir forest in eastern Washington. The fire was set to create summer elk range habitat. Image used with permission of James N. Long, Utah State University, Bugwood.org.

 

grand fir

lowland white fir

More info for the terms: cover, forest, tree

Grand fir provides good thermal and hiding cover, often close to water, for big game animals [108]. Young trees provide good cover for grouse and small mammals including squirrels, chipmunks, and pikas [127]. Grand fir's thick boughs provide shelter during rainstorms and provide roosting sites for grouse, pileated woodpecker, Williamson's sapsucker, pygmy nuthatch, Vaux's swift, and red crossbill [14,127,27,30]. Lists of bird and mammals that use grand fir in the Blue Mountains are available [180].

Old-growth live grand fir and grand fir snags provide nesting sites for woodpeckers, sapsuckers, deer mouse, bushy-tailed woodrat, American marten, fisher, spotted skunk, squirrels, and weasels [14,180,182]. Rats, mice, squirrels, weasels, and bears use downed grand fir logs and hollowed trunks as dens [14]. Pileated woodpecker and flammulated owl in the Blue Mountains of Oregon and Washington select large-diameter live grand fir, especially trees with broken tops that are extensively decayed by Indian paint fungus (Echinodontium tinctorium), for nesting [2,180,26,31,32]. Most grand fir may not attain a large enough girth to be preferred pileated woodpecker nesting sites, however. On the Coram Experimental Forest of northwestern Montana, pileated woodpecker preferred nesting in large-diameter, fungi-decayed western larch, Pacific ponderosa pine, western white pine, and black cottonwood (Populus trichocarpa) over grand fir, which was less common and generally smaller in dbh than the preferred nest tree species [129].

More info for the terms: forest, tree

Grand fir is a native tree. It characteristically has a wide crown, although there is considerable variation in crown width and continuity [14,57]. Heights of mature trees range from 140 to 200 feet (43-61 m) along the coast and from 131 to 164 feet (40-50 m) inland [71,104]. The bole of mature trees may reach 79 inches dbh (200 cm) on the Washington coast but usually ranges from 20 to 40 inches dbh (51-102 cm) [71]. Bark is thin on young trees (mean=0.9 cm for a 20-cm diameter tree) and moderately thick at maturity (m=1.7 cm for a 40-cm diameter tree) [14,144,169]. Finch [64] projected that the bark of a grand fir is 4.3% of the tree's dbh. (For comparison, western white pine and western larch are 1.8 and 7.4% of tree dbh, respectively).

Grand fir has a well-developed taproot [14,103,124,134]. On dry sites the taproot grows to moderate depths while on moist sites shallow lateral roots prevail, and the taproot may be absent [71]. Depth of horizontal roots is moderate compared to associated conifers [103,124,134].

Several morphological characteristics of grand fir lend to its relative flammability. Branching habit is low and dense; stands tend to be dense as well [169]. The foliage has a higher surface-to-volume ratio than that of associated conifers, and the needles are retained longer on the tree (m=7 years) [112]. On the Priest River Experimental Forest in northern Idaho, foliage comprised a greater proportion of total crown weight in grand fir than in 8 associated conifer species. Biomass allocation to smaller-diameter branchwood (< 2 inches (5 cm)) relative to larger-diameter branchwood was also greater in grand fir than most associated conifers [57].

Older grand fir support pervasive rotting fungi but frequently reach 250 years of age and occasionally exceed 300 years [14,71]. Camp [34] found that in the Cascade Range of Washington, grand fir in 21 late-successional stands ranged from 15 to 256 years of age, with a mean age of 83 years.

Grand fir is moderately drought tolerant [34].

Grand fir has a split distribution. Along the Pacific Coast it occurs from southern British Columbia south to Sonoma County, California, and east to the Cascade Range of central Oregon. In the continental interior it occurs from the Okanagan and Kootenay lakes region of British Columbia south to eastern Oregon, central Idaho, and west of the Continental Divide in Montana [71,174].

Grand fir is planted for lumber and as an ornamental in Hawaii [168] and Europe [141].

More info for the terms: climax, crown fire, extreme fire behavior, fern, fire cycle, fire regime, fire severity, forest, fuel, historical fire regime, lichen, low-severity fire, mixed-severity fire, series, severity, stand-replacing fire, surface fire

Adaptations to fire: Grand fir is moderately resistant to frequent surface fire. It has thin bark and is easily killed when young, but the bark is thick enough at maturity (about 2 inches (5 cm)) to provide resistance to low- and moderate-severity fires [3,169,44,50,69,89,92]. Compared to other Pacific Coast conifers, it is less fire resistant than coastal Douglas-fir but more so than western hemlock and Pacific silver fir [70]. Inland, it is less fire resistant than western larch, Pacific ponderosa pine, and Rocky Mountain Douglas-fir; about the same as white fir; and more fire resistant than western white pine, subalpine fir, Engelmann spruce (Picea engelmannii), and Rocky Mountain lodgepole pine [148,70]. Fire-scarred grand fir are susceptible to heart rot [7,9,14,108,62].

Grand fir does not survive crowning or severe fire. Its low, dense branching habit, flammable foliage, and tendency to develop dense stands with heavy lichen growth increase the likelihood of torching and mortality from crown fire [44,50,69,169].

Fire strongly influences grand fir's ecological niche and successional role [91,108]. In coastal British Columbia grand fir occurs in areas of relatively low summer rainfall and high summer temperatures, suggesting that its range may be restricted to sites with higher fire frequencies compared to moister surrounding forests with longer fire return intervals [155]. On many Pacific Northwest sites, however, grand fir only dominates sites where fire is excluded. Fire history studies show that Oregon white oak, Port-Orford-cedar (Chamaecyparis lawsoniana), Pacific ponderosa pine, western larch, and/or coastal Douglas-fir were maintained as site dominants by frequent surface fires that eliminated young grand fir [90,91,81]. After cessation of Native American burning in the Willamette Valley of Oregon (around 1850), grand fir has successionally replaced Oregon white oak and coastal Douglas-fir on most sites. Coastal Douglas-fir retains dominance only on the driest sites in the valley [42]. Although grand fir is not usually seral on sites with frequent fires, it may be either climax or seral on sites that experience infrequent crown fires [91].

FIRE REGIMES: Fires in grand fir types were historically of mixed severity, with fire behaviors ranging from frequent low-severity, nonlethal surface fire to infrequent, stand-replacing crown fire [9,3,5,18,139,12,166,19]. The grand fir series can roughly be divided into warm/dry types and warm/moist types. In warm/dry types, the historical fire regime was frequent (5-50 year), low-severity fire that favored Pacific ponderosa pine and western larch [11,34,170,190]. For example, a mean fire return interval of 47 years is reported for the Blue Mountains [190], with a range of 33 to 100 years [194]. Historically, fire severity in grand fir types of the Blue Mountains was often moderate, with a wider range of fire severities than Douglas-fir types [3]. Dry grand fir/graminoid types with understories of elk sedge or pinegrass typically experienced frequent surface fires (10- to 25-year intervals) [6,128,191].

FIRE REGIMES in northern Idaho and western Montana were historically similar to those in the Blue Mountains, but fire return intervals showed a wider range (3-200 years) [9,11]. On a dry site in the Bitterroot National Forest of western Montana, Arno [162,171] reported a mean fire return interval of 17 years between 1735 and 1900, with a range of 3 to 32 years. He attributed the short fire return interval to the relative scarcity of the grand fir series there, so that grand fir had "fire frequencies much like those in surrounding major series" such as Rocky Mountain Douglas-fir [16,12].

Mixed-severity fires with longer return intervals (25-100 years) were more common on cooler, moderately moist grand fir types with Rocky Mountain maple, Pacific yew, oak fern (Gymnocarpium dryoptera), or sword fern (Polystichum munitum) understories. FIRE REGIMES shifted to moderate severity on these wetter sites, and stand-replacement fires were more common [3,6,34,12,166,19]. Fire-scarred, mature grand fir trees in northern Idaho have withstood moderate-severity surface fires once or twice a century [18]. Camp [34] reported that fire history was complex on warm/moist forests of the eastern slope of the Cascade Range in Washington, with evidence of both frequent, low-severity fires and infrequent severe, stand-replacing fires. Sites experiencing severe fire often escaped fire through 2 to 3 surface fire cycles that occurred in surrounding forest. These long-unburned sites developed into multi-layered grand fir forest that functioned as old-growth fire refugia until the next severe fire cycle. Presettlement sites of fire refugia occurred most often on north-facing aspects, benches, valley bottoms, and stream confluences and headwalls [34,35].

Long-interval (> 100 years), severe fires were most common on wet grand fir habitat types [12,166,19]. Moist types are highly productive and have large fuel loads [94]. Barrett [18] found that fires in grand fir of the Clearwater National Forest in northern Idaho were usually large and exhibited behavior of (1) moderate to severe surface fires that killed the grand fir but left a few fire-resistant seral conifers, and (2) running crown fires (with individual runs of several hundred acres) that killed entire stands. Even given this extreme fire behavior, there was also evidence of low-severity surface fires, particularly on north slopes, that scarred but did not kill grand fir [18]. Barrett and Arno [19] found that patchy, stand-replacement fires with a mean return interval of 119 years typified FIRE REGIMES in Rocky Mountain Douglas-fir/grand fir habitats of the Selway-Bitterroot Wilderness in northern Idaho. A minority of stands experienced mixed-severity fire of nonuniform spread. Long-interval, stand-replacing fire also occurred historically in the relatively moist Swan Valley of western Montana. The Swan Valley also shows evidence of a mixed fire regime, with a mosaic of stands of varying age and composition [9]. Fire return intervals in the Swan Valley ranged from 20 to 300+ years, with a mean of 150 years [9,10].

FIRE REGIMES for plant communities and ecosystems where grand fir is a common associate are summarized below. Find further fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find FIRE REGIMES".

Community or Ecosystem Dominant Species Fire Return Interval Range in Years Pacific ponderosa pine* Pinus ponderosa var. ponderosa 1-47 [25] Rocky Mountain lodgepole pine* P. contorta var. latifolia 25-300+ [12,151] Rocky Mountain Douglas-fir* Pseudotsuga menziesii var. glauca 25-100 [25] coastal Douglas-fir* Pseudotsuga menziesii var. menziesii 95-242 [138,149] quaking aspen (west of the Great Plains) Populus tremuloides 7-100 [132,82] redwood Sequoia sempervirens 7-25 [66,178] *Fire-return interval varies widely; trends in variation are noted in the Species Review.  

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More info for the term: phanerophyte

RAUNKIAER [147] LIFE FORM:
Phanerophyte

More info for the term: mesic

Climate and moisture regime: Grand fir tends to dominate moderately moist habitats. In the northern Rocky Mountains, grand fir habitat types indicate areas where the climate is moderated by the Pacific maritime influence [43,145,171]. Generally, drier sites are occupied by Douglas-fir while western redcedar and western hemlock dominate wetter habitats [10,38,131]. Inland, grand fir is most abundant on sites averaging 25 inches (635 mm) or more annual precipitation that are either too dry for, or beyond the range of, western hemlock and western redcedar [14]. Habeck [84] found that in the Selway-Bitterroot Wilderness of northern Idaho and western Montana, grand fir forests were most extensive on mid-elevation (3,500-4,00 feet), mesic slopes. They fingered into wetter, western redcedar types and were scarce on drier types. Grand fir is a relatively minor stand component in wet, dense coastal forests [187]. In southern British Columbia, it is most common on moist soils and is infrequent on dry or wet soils [117]. Although it is the most drought-tolerant of the Pacific Northwest firs, moisture is limiting in grand fir's southernmost distribution. Grand fir occurs only on moist slopes in northeastern California [174]. West of the Cascade Range in Oregon and California, it occurs mainly on moist valley bottoms [14].

Grand fir is tolerant of fluctuating water tables and floods [117].

Soils: Soil parent materials in which grand fir grows include sandstone, pumice, weathered lava or granite, and gneiss [71,31]. Grand fir is not generally restricted by soil type but does best on streamside alluvium and deep, nutrient-rich valley bottoms [71,117,155,174]. If there is adequate moisture, grand fir in central and eastern Oregon grows on pumice and other shallow, exposed soils [71]. On the Mendocino Coast of California grand fir occurs on soils of pH 5 [107].

Elevation: Grand fir occurs at elevations up to 6,000 feet (1,830 m) in the Cascade Range and northern Rocky Mountains [14,71]. West of the Cascade Range, it is usually restricted to low-elevation valleys [14]. Elevations are listed below by region.

  Minimum feet (m) Maximum feet (m) western British Columbia   sea level 1000 (305) [14] California   sea level 5000 (1525) [14,71,102,174] Idaho   2000 (610) 6000 (1830) [122,19] western Montana   4300 (1290) 4700 (1410) [11] Oregon Cascades   ---- 6025 (1825) [14,71,174] western Oregon   sea level 3000 (915) [14] Washington Cascades   ---- 4000 (1220) [14,71,174] western Washington   590 (180) 1000 (305) [14,174]

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This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

More info for the term: cover

SAF COVER TYPES [56]:

206 Engelmann spruce-subalpine fir

207 Red fir

210 Interior Douglas-fir

211 White fir

212 Western larch

213 Grand fir

215 Western white pine

218 Lodgepole pine

221 Red alder

222 Black cottonwood-willow

224 Western hemlock

225 Western hemlock-Sitka spruce

226 Coastal true fir-hemlock

227 Western redcedar-western hemlock

228 Western redcedar

229 Pacific Douglas-fir

230 Douglas-fir-western hemlock

231 Port-Orford-cedar

232 Redwood

233 Oregon white oak

237 Interior ponderosa pine

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

ECOSYSTEMS [77]:

FRES20 Douglas-fir

FRES21 Ponderosa pine

FRES22 Western white pine

FRES23 Fir-spruce

FRES24 Hemlock-Sitka spruce

FRES25 Larch

FRES27 Redwood

FRES28 Western hardwoods

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This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

More info for the term: forest

KUCHLER [121] PLANT ASSOCIATIONS:

K001 Spruce-cedar-hemlock forest

K002 Cedar-hemlock-Douglas-fir forest

K003 Silver fir-Douglas-fir forest

K006 Redwood forest

K007 Red fir forest

K008 Lodgepole pine-subalpine forest

K011 Western ponderosa forest

K013 Cedar-hemlock-pine forest

K014 Grand fir-Douglas-fir forest

K015 Western spruce-fir forest

K025 Alder-ash forest

K026 Oregon oakwoods

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This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):

More info for the terms: cover, forb, shrubland

SRM (RANGELAND) COVER TYPES [163]:

109 Ponderosa pine shrubland

110 Ponderosa pine-grassland

409 Tall forb

422 Riparian

More info for the term: duff

Young grand fir have thin bark and are easily killed by fire [109,112]. Trees under 4 inches (10.2 cm) diameter at ground level are most susceptible to direct fire mortality [89,92]. The bark thickens as trees age, and mature trees are moderately resistant to fire [12,34]. Ground fires burning into the duff injure shallow roots and may kill even mature trees [44,67,71,108,164].

Baker [71] found that grand fir seedlings in the laboratory were killed by exposing the stems to temperatures of 121 degrees Fahrenheit (49oC) for 10 minutes.

More info for the terms: cover, forest, tree

Browsing: Livestock seldom browse grand fir but do use it for shade [108]. Deer, elk, and moose may resort to eating fir (Abies spp.) needles in winter [127]. Fir needles are a major part of the diet of blue, ruffed, and sharp-tailed grouse. Squirrels, other rodents, and some birds such as nuthatches and chickadees eat the seeds [127,179].

Habitat use: Mature grand fir provide nesting and feeding sites for a variety of arboreal animals [14]. Several species of owl including the flammulated [32] and northern spotted owl use grand fir habitats [36]. Marbled murrelet nest in old-growth grand fir-coastal Douglas-fir habitat in northern California [142]. Woodpeckers use grand fir habitats but often select other tree species within the type over grand fir for foraging and nesting [14,26,29,118,129]. In a study of woodpecker foraging activities in the Blue Mountains of Oregon, Bull and others [30] found that foraging among 8 species of woodpecker was consistently lower on grand fir than on Pacific ponderosa pine, Rocky Mountain lodgepole pine, western larch, and Rocky Mountain Douglas-fir.

Most big game species do not prefer mature grand fir forests, but they use seral-stage grand fir habitats. Irwin and Peek [105] found that elk in northern Idaho preferred early-seral, grass and shrub/grass stages of grand fir habitats, especially when foraging in spring. When seeking shade and resting cover, elk tended to use adjacent western hemlock and lodgepole pine over grand fir forest. In the Selway-Bitterroot Wilderness of northern Idaho, mule deer avoided mature grand fir/queencup beadlily habitat but used 3-year-old burns in grand fir/queencup beadlily in proportion to availability. White-tailed deer tended to avoid both mature and old-seral grand fir/queencup beadlily habitats [113].

Unlike most big game, moose prefer old-growth grand fir forest. Pierce and Peek [146] found that grand fir/Pacific yew was critical winter habitat for Shiras moose in north-central Idaho, with Pacific yew being their primary winter food item.

More info for the terms: association, climax, fern, ferns, fire regime, forest, habitat type, natural, shrub, succession

Grand fir is an indicator of productive forest sites [80,88,117]. Mature grand fir stands are usually floristically diverse [43,71]. Common plant community associates of grand fir are grouped below by region.

Western Montana and northern Idaho: In Montana, the grand fir habitat type is often bound by Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) habitats on warmer, drier sites and by subalpine fir (Abies lasiocarpa) on cooler sites. In northern Idaho, the grand fir type merges into western hemlock (Tsuga heterophylla) and western redcedar (Thuja plicata) on cooler sites [145]. Western larch (Larix occidentalis), Rocky Mountain lodgepole pine (Pinus contorta var. latifolia), and Pacific ponderosa pine (P. ponderosa var. ponderosa) are major seral species in climax interior grand fir habitats [49,74,145,172]. Understory associates are many: pachistima (Pachistima myrsinites), common snowberry (Symphoricarpos albus), Saskatoon serviceberry (Amelanchier alnifolia), baldhip rose (Rosa gymnocarpa), blue huckleberry (Vaccinium membranaceum), white spirea (Spiraea betufolia), twinflower (Linnea borealis), beargrass (Xerophyllum tenax), queencup beadlily (Clintonia uniflora), and wild ginger (Asarum caudatum) are among the most common [43,145,49].

Washington, Oregon, and California: Grand fir occurs on moist to dry sites in the Cascade Range. Overstory associates on moist sites may include western hemlock, western redcedar, Pacific silver fir (Abies amabilis), and Sitka spruce (Picea sitchensis)[46]. Mid- and understories are diverse and dense on moist sites and commonly include Pacific yew (Taxus brevifolia), red alder (Alnus rubra), Pacific dogwood (Cornus nuttallii), redstem ceanothus (Ceanothus sanguineus), shinyleaf ceanothus (C. velutinus), thimbleberry (Rubus parviflorus), huckleberries (Vaccinium spp.), pachistima, queencup beadlily, and/or vanillaleaf (Achlys triphylla). Hot, dry sites are usually open and less diverse, with Pacific ponderosa pine, Rocky Mountain Douglas-fir and western white pine (Pinus monticola) as common overstory associates. Understories are typically grassy and dominated by pinegrass (Calamagrostis rubescens) and elk sedge (Carex geyeri) [33,115,181].

Old-growth grand fir on the Umatilla National Forest, Oregon. Image used with permission of Dave Powell, USDA Forest Service (retired), Bugwood.org.

In the Willamette Valley of Oregon, associates of grand fir in coastal Douglas-fir-Oregon white oak (Pseudotsuga menziesii var. menziesii-Quercus garryana) include incense-cedar (Calocedrus decurrens), Pacific ponderosa pine, California black oak (Q. kelloggii), chinquapin (Chrysolepsis chrysophylla), Pacific madrone (Arbutus menziesii), and bigtooth maple (Acer macrophyllum) [42].

In southwestern Oregon and northwestern California, grand fir is common in mixed evergreen and conifer forests [102], where it is associated with Shasta red fir (Abies magnifica var. shastensis), noble fir (A. procera), redwood (Sequoia sempervirens), western hemlock, Sitka spruce, and coastal Douglas-fir [2,102]. Mid-story and shrub associates in redwood forest of Redwood National Park, California, include tanoak (Lithocarpus densiflorus), Pacific madrone, evergreen huckleberry (Vaccinium ovatum), red huckleberry (V. parvifolium), and Pursh's buckthorn (Frangula purshiana). Commonly associated ferns and herbs include western sword fern (Polystichum munitum), deer fern (Blechnum spicant), Oregon oxalis (Oxalis oregana), and salal (Gaultheria shallon) [125].

Hall [91] arranged grand fir plant associations by fire regime and grand fir's successional position in the plant community. Detailed lists of understory plants are included in habitat type and community type manuals for each region. Vegetation classifications describing plant communities in which grand fir is a dominant species are listed below.

Forest habitat types of northern Idaho: a second approximation [43]

Forest vegetation of eastern Washington and northern Idaho [49]

Classification of grand fir mosaic habitats [61]

Forest vegetation of the montane and subalpine zones, Olympic Mountains, Washington [72]

Natural vegetation of Oregon and Washington [74]

Plant communities of the Blue Mountains in eastern Oregon and southeastern Washington [88]

Classification and management of Montana's riparian and wetland sites [96]

Plant association and management guide: Willamette National Forest [101]

Riparian reference areas in Idaho: a catalog of plant associations and conservation sites [106]

Forest habitat types of Montana [145]

Major Douglas-fir habitat types of central Idaho: a summary of succession and management [173]

Plant association and management guide for the grand fir zone, Gifford Pinchot National Forest [181]

Forest plant associations of the Colville National Forest [193]

The redwood forest and associated north coast forests [197]

More info for the term: tree

Tree

More info for the terms: cover, fire exclusion, forest, prescribed fire, series, tree, tussock

Pests and diseases: Grand fir is susceptible to a variety of pathogens [16,22,71,189,139,174]. Fire exclusion and selective harvesting of pine and western larch that began at the turn of the century have resulted in an unprecedented abundance of grand fir in many areas of the interior West. Disease and mortality are greater in fir-dominated stands than in stands dominated by seral conifers. As a result, these late-successional stands are dominated by diseased, suppressed, and/or dead grand fir [63,139].



Grand fir is susceptible to heart- and root-decaying fungi because it does not exude heavy pitch over wounds or contain decay-inhibiting properties in its wood. Annosus (Fomes annosus), armillaria (Armillaria ostoyae), and Indian paint fungus (Echinodontium tinctorum) are among the most ubiquitous. Annosus gains entry through fire scars, dead branches, frost cracks, and mechanical injuries [7,8,16,71,62]. Armillaria infects roots by vegetative spread of mycelium across roots. Indian paint fungus infects small branchlet stubs. Fire injury to host trees may stimulate dormant Indian paint fungus to resume growth, accelerating decay [62].



Grand fir is susceptible to numerous insects. The most troublesome are
western spruce budworm, Douglas-fir tussock moth, western balsam bark beetle, and fir engraver beetle [71,80,117]. Timing of, and slash disposal following, thinning are important precautions in avoiding fir engraver attacks [189]. Several genera of moths, beetles, and flies eat the cones and seeds
[65,71]. A list of insecticides suitable for grand fir is available
[93].



Grand fir is the principal host of white fir dwarf-mistletoe (Arceuthobium abietinum f. sp. concoloris) in the Coast Ranges of Oregon and northern California and the Blue Mountains. Hemlock dwarf-mistletoe (A. tsugense) infects grand fir occasionally [86,99,100].



Silviculture: Grand fir can contribute considerable volume to forest stands [117,182], but its strong tendency to develop heart rot makes it less desirable as a leave tree than pines and western larch [9].
Hall [90] compared and summarized several
studies of grand fir productivity. Grand fir grows rapidly on cutover or burned
sites under favorable conditions [113]. Seedlings on Vancouver Island have grown as much as 3 feet (0.9 m) per year [14]. Grand fir may respond to release, but growth depends on prerelease vigor, site, and logging damage [60,80,117]. Older, low-vigor trees continue to
grow at a very slow rate while young, vigorous trees show rapid growth [60,117,159]. Stocking level recommendations for grand fir are available [40,159].



Recommendations for managing grand fir have been summarized for the eastern
Cascades of Washington [22], the Blue Mountains [150], and northern Idaho [189].



Harvesting for restoration: Restoring ponderosa pine, western larch, and other fire-dependent communities without the use of prescribed fire is difficult but possible. Mutch and others [139] recommend a series of stand entries, using selective harvesting of grand fir and other shade-tolerant species and mechanical treatment of fuels, where prescribed burning cannot be achieved. They caution, however, that soil productivity and general forest health are usually reduced, and exotic weed cover increased, under treatments other than prescribed fire.



Herbicides: Grand fir is rated intermediate in sensitivity to glyphosate [22].

Grand fir foliage (oven-dry weight) contains approximately 1.4% nitrogen, 0.20% phosphorus, and 0.7% potassium [55].

CA

HI

ID

MT

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BC

Grand fir is grown commercially for Christmas trees [71,175]. It is also planted as an ornamental [71,120].

The Salish of Vancouver Island, British Columbia, collected pitch from grand fir blisters, rubbed it into wooden implements, and scorched it to provide a varnished finish [184]. They made a decoction from the branches and cones to treat respiratory ailments; a poultice from the pitch to treat wounds, burns, and sore eyes; and a decoction of the bark, sap, and sapwood to treat gonorrhea [185].

Firs (Abies spp.) are generally unpalatable to big game animals. Deer, especially white-tailed deer, browse grand fir in winter when more palatable forage is unavailable [127].

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More info for the terms: phenology, seed

Time of grand fir budding varies over several months depending on early spring temperatures. Generally, budding occurs from late March to mid-May at low elevations and in June at higher elevations [71,75]. Shoot elongation follows bud burst; cones generally open for pollination during shoot elongation [54,75]. Cones ripen from August to September of the same year and begin to disintegrate and dispense seed about a month later [71,75].

Grand fir phenology in several locations is given below [179]:

Location Bud break Pollination Cones ripen Seeds disperse BC mid-March April August ---- (no data) northern ID mid-June ---- August early Sept. western OR and WA mid-April to mid-May ---- ---- mid-Sept. Linn Co., OR mid-June ---- ---- ---- Mendocino Co., CA early April ---- ---- ----
Phenological observations of grand fir made over an 8-year period in northern Idaho and western Montana are summarized below [157]:

  Earliest date Average date Latest date Shoots start April 19 May 18 June 25 Buds burst April 5 May 25 June 11 Pollen starts May 1 June 4 July 2 Pollen ends May 20 June 20 July 14 Shoot growth ends June 9 August 3 August 31 Winter buds formed June 16 August 14 October 11 Cones full size July 7 August 5 August 26 Cones open August 30 September 9 October 11

More info for the terms: association, fuel, seed, succession, tree, wildfire

Grand fir regeneration is common after fire [9,155]. Seedlings establish on burns mostly from off-site seed sources [8,109,182]. Mature grand fir that survive a fire provide an on-site seed source [8]. Fire provides a favorable seedbed. When different substrates were compared, grand fir germination was best on ash or mineral soil [69,162]; however, seedling mortality may be higher on burned soils due to higher surface temperatures on blackened compared to unburned soils [159]. Seedlings often establish in the 1st few postfire years. For example, following a severe wildfire in a mature grand fir/queencup beadlily association in the Blue Mountains of Oregon, grand fir seedlings were 1st noted in study plots at postfire year 5 [109]. Following the Sundance Fire in northern Idaho, grand fir seedlings were 1st noted in postfire years 4 to 9, with time of 1st emergence varying among study plots. [176]. Because grand fir seedlings are not as drought tolerant as many conifer associates, grand fir establishment is sometimes slow or delayed by drought, but grand fir is usually established as component of seral vegetation by 20 to 30 years after fire [133,196]. Grand fir regeneration is also common after fire thins a dense overstory [9]. As a shade-tolerant tree, grand fir continues to establish until canopy closure in late succession [112].

Low-severity fire may have little effect on grand fir. A "light" fire in an early-seral grand fir/twinflower association the Oregon Blue Mountains killed the pole-sized overstory conifers (grand fir, Rocky Mountain Douglas-fir, and Rocky Mountain lodgepole pine), but their relative coverage remained similar to prefire levels during early postfire seedling establishment. Prefire coverage of grand fir was 5% compared to 3% coverage at postfire year 5 [109].

FEIS provides these Fire Studies on plant communities in which grand fir is an important component of the vegetation:

• Research Project Summary: Prescribed and wildfire in clearcut mixed-conifer forests of Miller Creek and Newman Ridge, Montana
• Research Paper: A comparison of dry and moist fuel underburning in ponderosa pine shelterwood units in Idaho

More info for the terms: adventitious, crown residual colonizer, initial off-site colonizer, secondary colonizer, tree

POSTFIRE REGENERATION STRATEGY [177]:

Tree without adventitious bud/root crown
Initial off-site colonizer (off-site, initial community)
Crown residual colonizer (on-site, initial community)
Secondary colonizer - off-site seed

More info for the terms: cone, density, forest, frequency, habitat type, litter, presence, root crown, seed, tree

Grand fir cones. Image used with permission of Dave Powell, USDA Forest Service (retired), Bugwood.org.

Cones: Cone and seed production begins at 20 to 50 years of age, and cone productivity increases with age [54,174,183]. In a good year, an average grand fir tree produces over 40 cones [71]. A year of heavy cone production is typically followed by several years of light production [73,158,174,185,179]. Pollen and ovulate cones begin development during the summer and go through a period of winter dormancy before pollination, fertilization, and seed production the 2nd spring and summer [165]. Hard frosts may inhibit cone development [71].

Seeds: Trees in Oregon and Washington may produce over 200 seeds per cone [74]. The number of seeds produced annually on inland sites ranges from 12,800 per acre (31,600/ha) to 23,500 per acre (58,100/ha) [71]. The winged seeds are of medium weight compared to other conifers and are wind-dispersed a few hundred feet from the parent [14,183]. Over 4 years (1974-1977), grand fir seed rain in central Oregon ranged from 810 to 60,718 seeds per acre (2025-151,795/ha) per year; sound seed ranged from 4.5 to 33.3% [158]. Seeds stratify over winter and are not viable beyond the 1st spring [71,123,148,183]. Germination is extremely variable but is seldom over 50% [14,71,54]. Li and others [126] found that in collections from coastal British Columbia, light increased germination rates in unstratified seed (light/dark germination= 89/80%) but had no significant effect on germination rates of stratified seed (92/93%, p=0.05) [71].

Seedling establishment: Despite the perception of grand fir as a primarily late-successional species, it shows good establishment on recently disturbed sites [10,78], and mineral soil is the most favorable seedbed [78,158]. Grand fir also establishes in light to moderate understory shade and in small openings in mature forests [10]. Uneven-aged grand fir establishment may occur over an "extended period of years" [87].

Over 30% of grand fir seedlings die during the 1st year, and an additional 10% die their 2nd year. Biotic agents and drought usually cause early losses. Initial seedling root penetration is deep on sites exposed to full sunlight so that seedlings are relatively resistant to drought. However, on shaded sites root penetration is slow, and drought is the major cause of seedling mortality [71,45]. East of the Cascade crest, water deficits are seldom critical past the seedling stage [103,198].

Grand fir has shown good establishment after silvicultural treatments. After shelterwood cutting in grand fir-Shasta red fir in central Oregon, seedling establishment of both firs was best on mineral soil (created by bulldozing). Seedling density decreased as litter and slash depth increased [158]. In central Idaho, grand fir showed better seedling establishment than 5 associated conifers on logged sites, establishing on clearcuts or shelterwood cuts within an average of 7 years (range=0-30 yrs). It was less successful than most conifer associates on broadcast burned sites, but still showed 33% frequency on lightly scarified burns and 23% frequency on heavily scarified burns [78]. A western redcedar-western hemlock/pachistima habitat type on the Deception Creek Experimental Forest of northern Idaho was horse-logged (shelterwood cut or clearcut followed by broadcast burning). Four years after treatments, grand fir showed moderately good seedling establishment compared to 6 other conifer species; only western white pine and western hemlock established in greater densities. Density of grand fir averaged 1.4 seedlings/yd2 (1.8/m2) on the shelterwood site and 0.1 seedling/yd2 (0.2/m2) on the clearcut and broadcast burned site. Grand fir continued to establish during the 20-year study period. Twenty years after treatment, grand fir density was still moderate compared to other conifers, at 12.1 stems/yd2 (15.1/m2) on the shelterwood and 2.5 stems/yd2 (3.1/m2) on the clearcut [23].

Growth: Grand fir is the fastest growing of all North American firs. It may reach 140 feet (43 m) in 50 years on Coastal Range and interior northern California sites [156]. On the eastern slope of the Cascade Range, Washington, grand fir grew more rapidly in the absence of Douglas-fir but was not affected by presence or absence of lodgepole pine [39].

Vegetative reproduction: Grand fir reproduces solely from seed and does not sprout from the root crown [71,155]. It may produce epicormic branches on the lower bole if light and space become available. Epicormic sprouting may contribute considerable volume to a disturbed stand [14].

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This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

BLM PHYSIOGRAPHIC REGIONS [21]:

1 Northern Pacific Border

2 Cascade Mountains

3 Southern Pacific Border

5 Columbia Plateau

8 Northern Rocky Mountains

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More info for the terms: climax, fern, forest, seed, series, succession, tussock

Grand fir occurs in the overstory of both seral and late-successional forests [9,71,91,47,52,83,87]. It is climax throughout the grand fir series and is a major seral species in some western redcedar, western hemlock, subalpine fir, and Pacific silver fir habitat types [91]. It exhibits moderate growth in the open, yet is shade-tolerant enough to establish and grow beneath an open forest canopy [9,60,130,145,183]. Grand fir is not as shade-tolerant as western redcedar, hemlocks, or other firs and does not establish beneath a closed canopy [71,156,148,155,187,183]. Succession to a grand fir overstory is usually slower on shrubfields than on sites where grand fir developed beneath a forest canopy [10,49,157]. In grand fir habitats on Clearwater River drainages in northern Idaho, succession to a woody overstory was retarded by bracken fern (Pteridium aquilinum) or western coneflower (Rudbeckia occidentalis) invasion, and by northern pocket gopher browsing young grand fir and other conifer regeneration [59].

Grand fir does not require disturbance to establish and persist on most sites [15,188]; however, where western hemlock or western redcedar is the climax dominant, fire or other periodic disturbance is needed to maintain grand fir [14]. Grand fir may colonize a site soon after fire or other stand-replacing disturbance. Grand fir advance regeneration and seedling coverage were highest among 5 conifers following a severe Douglas-fir tussock moth outbreak that killed most of the grand fir-Douglas-fir overstory on the Wenaha-Tucannon Wilderness, Oregon. Although ponderosa pine seedlings showed faster growth rates than grand fir seedlings, the authors predicted that in the absence of fire, grand fir would continue to dominate the site despite repeated tussock moth outbreaks [192].

In the Swan Valley of western Montana, a grand fir understory usually developed in late succession beneath Douglas-fir that replaced early-succession lodgepole pine and western larch. Grand fir seedling establishment on early seral sites occurred mainly where lodgepole pine and western larch seed sources were lacking, such as the center of large, stand-replacement burns [9]. Descriptions of seral communities that occur in grand fir habitat types in Montana's Swan Valley and in central Idaho are available [9,43,171,172].

Dale and others [47] developed a model of long-term succession (500+ years) in western Washington and Oregon. The model predicts that in the absence of disturbance, grand fir is an early mid-seral species that is eventually replaced by Pacific silver fir, western hemlock, and mountain hemlock (Tsuga mertensiana). The model also predicts successional pathways after disturbance events including fire, windstorm, insect outbreak, and clearcutting.

The scientific name of grand fir is Abies grandis (Dougl.) Lindl. (Pinaceae) [104,110,102].



Grand fir hybridizes with white fir (A. concolor) [116,45]. A broad zone of intergraded grand × white fir populations occurs from northeastern Washington and Oregon south to northern California and east to west-central Idaho [174].

Since grand fir grows well in a variety of environments including riparian areas, it is a good candidate for planting on disturbed sites [91,95].

Grand fir is a commercially valuable timber species. The wood is compatible with adhesives, has low shrinkage, and is good for pulping and other light-duty uses [14,21,71,167]. It is lighter in weight and not as strong as the wood of most pines. The best commercial stands grow in the Nez Perce and Clearwater national forests of northern Idaho [71].

Grand fir is either a seral or climax species in different forest types within its range. On moist sites it grows rapidly enough to compete with other seral species in the dominant overstory. On dry sites it becomes a shade-tolerant understory and eventually assumes dominance as climax conditions are approached.

Grand fir is represented in 17 forest cover types of western North America: it is the predominant species in only one, Grand Fir (Society of American Foresters Type 213) (26). It is a major component of six other cover types: Western Larch (Type 212), Western White Pine (Type 215), Interior Douglas-Fir (Type 210), Western Hemlock (Type 224), Western Redcedar (Type 228), and Western Redcedar-Western Hemlock (Type 227). Grand fir appears sporadically in 10 other cover types.

In northern Idaho, grand fir is the major climax tree species in seven habitat types and is an important seral tree in the Thuja plicata, Tsuga heterophylla, and Abies lasciocarpa series of habitat types (5). The Montana forest ecological classification recognizes an Abies grandis series of three habitat types in which grand fir is the major climax tree (23). It is also a minor climax or seral tree in four other types in Montana. In central Idaho, Steele and others (28) described an Abies grandis series that includes nine habitat types and five phases in which grand fir is the climax tree.

The Abies grandis zone is the most extensive midslope forest zone in the Cascade Range of Oregon and southern Washington and the Blue Mountains of eastern Oregon. Grand fir is the climax tree species in 12 plant associations (15,18). It is also an important component of the mixed conifer communities in the Willamette Valley and Siskiyou Mountains of Oregon (16). In addition, grand fir grows sporadically in the Tsuga heterophylla, Picea sitchensis, and Abies amabilis zones in the coastal forests of Washington and Oregon (11).

Grand fir sometimes grows in pure stands but is much more common in mixed coniferous and hardwood forests. In forests east of the Cascade crest, it is associated with western white pine (Pinus monticola), western larch (Larix occidentalis), Douglas-fir (Pseudotsuga menziesii), western hemlock (Tsuga heterophylla), western redcedar (Thuja plicata), lodgepole pine (Pinus contorta), ponderosa pine (Pinus ponderosa), and in certain areas, Engelmann spruce (Picea engelmannii), subalpine fir (Abies lasiocarpa), black cottonwood (Populus trichocarpa), Pacific yew (Taxus brevifolia), white fir (Abies concolor), incense-cedar (Libocedrus decurrens), sugar pine (Pinus lambertiana), Shasta red fir (Abies magnifica var. shastensis), and Oregon white oak (Quercus garryana).

Associates of grand fir in northwestern Oregon, western Washington, and southwestern British Columbia include Sitka spruce (Picea sitchensis), Pacific silver fir (Abies amabilis), and Port-Orford-cedar (Chamaecyparis lawsoniana), in addition to western redcedar, western hemlock, western larch, and Douglas-fir. It also is associated with these coast hardwoods: bigleaf maple (Acer macrophyllum), Oregon ash (Fraxinus latifolia), red alder (Alnus rubra), black cottonwood, and Oregon white oak.

In southwestern Oregon and northwestern California, at the southern limits of the range, grand fir is found with redwood (Sequoia sempervirens), and at higher elevations with Shasta red fir, white fir, noble fir (Abies procera), subalpine fir, and western white pine.

Shrubs commonly associated with grand fir include pachistima (Pachistima myrsinites), bristly black currant (Ribes lacustre), Saskatoon serviceberry (Amelanchier alnifolia), Rocky Mountain maple (Acer glabrum), twinflower (Linnaea borealis), birchleaf spirea (Spiraea betulifolia), huckleberry (Vaccinium spp.), Utah honeysuckle (Lonicera utahensis), mallow ninebark (Physocarpus malvaceus), common snowberry (Symphoricarpos albus), baldhip rose (Rosa gymnocarpa), princes-pine (Chimaphila spp.), Spalding rose (Rosa nutkana var. hispida), oceanspray (Holodiscus discolor), creeping hollygrape (Berberis repens), willow (Salix spp.), thimbleberry (Rubus parviflorus), rustyleaf menziesia (Menziesia ferruginea), and pyrola (Pyrola spp.).

Herbaceous species commonly found in various associations with grand fir include queenscup (Clintonia uniflora), false solomons-seal (Smilacina stellata), goldthread (Coptis occidentalis), Pacific trillium (Trillium ovatum), sweetscented bedstraw (Galium triflorum), pathfinder (trailplant) (Adenocaulon bicolor), wildginger (Asarum caudatum), Piper anemone (Anemone piperi), violet (Viola spp.), sandwort (Arenaria macrophylla), heartleaf arnica (Arnica cordifolia), strawberry Fragaria spp.), rattlesnake plantain (Goodyera oblongifolia), western meadowrue (Thalictrum occidentale), coolwort (Tiarella spp.), fairybells (Disporum oreganum), white hawkweed (Hieracium albiflorum), and sweetroot (Osmorhiza spp.). Graminoids frequently associated with grand fir are Columbia brome (Bromus vulgaris), pinegrass (Calamagrostis rubescens), western fescue (Festuca occidentalis), and sedge (Carex spp.). Additional species are associated with grand fir in the coastal region, where it grows with western hemlock, coastal Douglas-fir, Sitka spruce, and redwood.

Grand fir is found on a wide variety of sites. Average annual precipitation in its territory ranges from 510 to more than 2540 mm (20 to 100 in) in western Washington and on Vancouver Island. Annual precipitation in the Blue Mountains of eastern Oregon averages 360 to 990 mm (14 to 39 in). In northern Idaho, average annual precipitation is 510 to 1270 mm (20 to 50 in). Most of this precipitation occurs during winter. Generally 15 to 25 percent of the annual precipitation occurs during the growing season, May through August. On Vancouver Island, where average annual precipitation ranges from 680 to 2820 mm (27 to 111 in), only 50 to 130 mm (2 to 5 in) of rain falls during June, July, and August. Average annual snowfall ranges from a few centimeters on some coastal sites to more than 1270 cm (500 in) in the mountains of the interior (9).

Average annual temperatures range from 6° to 10° C (43° to 50° F); the average growing season temperature is 14° to 19° C (57° to 66° F). The frost-free season varies, ranging from about 60 to more than 250 days, and is very irregular from year to year. Frosts may occur in any month in the interior. The average growing season ranges from only 100 to 140 days in northern Idaho, 185 days on the Olympic Peninsula in western Washington, and 250 or more days in northern California (9).

During the period of stand development from establishment to maturity, several factors influence stand growth and yield. Grand fir is rated medium in fire resistance among species of the western white pine type; it is less resistant than thick-barked western larch, ponderosa pine, and Douglas-fir but more resistant than subalpine fir, western hemlock, and Engelmann spruce. Fire resistance is influenced by habitat. For example, in moist creek bottoms grand fir succumbs rapidly to ground fires, but on dry hillsides it is more resistant, largely because of its deeper root system and thicker bark. The needles are quite resistant to cold during the severest part of the winter. Grand fir leaves have been subjected to temperatures of -55° C (-67° F) without damage. Sudden extreme drops of temperature in the fall occasionally damage needles, but seldom are they fatal. Frost cracks and lightning scars appear more frequently on grand fir, however, than on its associates in the Inland Empire. The cracks cause little direct mortality but contribute to the spread of infection by decay fungi. Often small patches of trees are uprooted or broken by the accumulation of snow in the crowns of dense immature stands in the Inland Empire (9). In England young grand firs from Vancouver Island and western Washington are reportedly susceptible to late spring frost and drought crack (2).

Susceptibility to heart rot and decay is one of the more important factors in the management of grand fir. Indian paint fungus (Echinodontium tinctorium) is the most destructive fungus in forests east of the Cascade crest (17). In the Blue Mountains of Oregon and Washington, decay was reported responsible for losses of 14 percent of the gross merchantable cubic-foot volume and 33 percent of the board-foot volume in sawtimber-size grand fir trees (1). Fungi enter the tree through small shade-killed branchlets in the lower crown. After closure of the branchlet stub, infections become dormant. Years later the infections are reactivated when mechanical injuries allow air to enter the heartwood where the dormant infections are located (7). Therefore, centers of decay are closely related to logging scars, frost cracks, broken tops, and other mechanical injuries (21).

Indian paint fungus is rare in grand fir west of the Cascade crest where rapid growth rates close branch stubs quickly (7). Armillaria spp. and Phellinus weiri are the two most important root rot fungi. Poria subacida and Heterobasidion annosum also attack grand fir (17).

Numerous insects attack grand fir. The western spruce budworm (Choristoneura occidentalis) and Douglas-fir tussock moth (Orgyia pseudotsugata) have caused widespread defoliation, top kill, and mortality. The western balsam bark beetle (Dryocoetes confusus) and the fir engraver (Scolytus

ventralis) are the principal bark beetles attacking grand fir. The fir cone moth (Barbara spp.), fir cone maggots (Earomyia spp.), and several seed chalcids destroy large numbers of grand fir cones and seeds. The balsam woolly adelgid (Adelges piceae), often called "gout disease of fir," has destroyed grand fir in western Oregon and Washington and is a serious threat in southwestern British Columbia (12).

Grand fir trees are monoecious; male and female flowers are borne in clusters on branchlets of the previous season's growth in different parts of the same tree. Female flowers, producing cones and seeds, are short, spherical to cylindrical, and stand singly and erect on the uppermost part of the crown. Male flowers, pollen-bearing only, are ovoid or cylindrical and hang singly from the lower side of branches below the female flowers. This arrangement favors cross-fertilization. The cones mature in one season. Time of flowering may vary over several months, depending on temperatures during the weeks preceding flowering. Flowering occurs from late March to mid-May at lower elevations of most coastal locations, and in June at the higher elevations of the inland locations. The cones, mostly yellowish-green and occasionally greenish-purple, ripen from August to September of the same year, and seeds are dispersed approximately 1 month later (32).

Extreme frosts may occasionally inhibit normal cone and seed development. Several species of insects feed on the buds, conelets, and seeds of grand fir, sometimes destroying 10 to 25 percent of the year's seed crop (9).

Population Differences There are no recognized varieties of grand fir, although a green coastal form and gray interior form are often recognized. Five fairly distinct climatic forms of grand fir have been identified. The differences are mainly physiological and ecological (9). Provenance trials with grand fir in Europe have resulted in ranking U.S. seed origins. Seed sources west of the Cascade crest are preferred for planting in England and the lowland sites in Europe (20). Significant differences in height growth between trees from sources east and west of the Cascade crest have been reported but average growth of westside and interior seedlings is generally about the same (29). Most of the genetic variation available for tree improvement appears to be among stands but genetic gains can also be made by selecting individuals within stands.

Hybrids Grand fir crosses with both the concolor and lowiana varieties of white fir. Several studies have shown hybridization and introgression between grand fir and white fir in a broad zone extending from the Klamath Mountains of northern California through southwestern Oregon and through the Oregon Cascade Range into northeastern Oregon and west-central Idaho (30). Grand fir has been crossed with several European and Asiatic species (19). Natural hybrids have been reported between grand fir and subalpine fir in northern Idaho (6).

Longevity of grand fir is intermediate among true firs; trees 250 years old are common and occasional trees may be more than 300 years old. On optimum sites in the coastal lowlands of Washington, mature grand firs reach heights of 43 to 61 m (140 to 200 ft) at 51 to 102 cm (20 to 40 in) d.b.h.; occasionally they reach 76 m (250 ft) in height and 152 cm (60 in) in d.b.h. (11). Grand fir in the redwood forests of California reaches d.b.h. and heights as great as those attained in the coast Douglas-fir region. In northern Idaho grand fir normally grows to 35 to 46 m (115 to 151 ft) in height at 64 to 102 cm (25 to 40 in) in d.b.h. On the pumice soils of eastern Oregon it attains height of 30 to 40 m (98 to 131 ft) with d.b.h. of 51 to 91 cm (20 to 36 in). On exposed ridges of the Inland Empire, heights of 15 to 21 m (49 to 69 ft) and d.b.h. of 30 to 36 cm (12 to 14 in) are common (9).

The rapid early height growth nearly equals that of Douglas-fir on the Pacific coast and western white pine in Idaho. On Vancouver Island and western Washington sites, growth of 79 to 89 cm (31 to 35 in) per year was reported. Trees 43 m (141 ft) tall at 50 years of age have been measured. In Idaho early height growth of 15 to 20 cm (6 to 8 in) on average sites and 30 to 36 cm (12 to 14 in) on optimum sites has been reported. In the dry pumice soils of eastern Oregon, average juvenile height growth up to 13 cm (5 in) per year has been reported. On these dry sites good height growth is delayed until the taproots reach ground water. At some time in the third decade, height growth receives considerable impetus and annual height growths of 51 to 89 cm (20 to 35 in) or more are common (9).

Among pole-size trees, growth is nearly equal to the more shade-intolerant western white pine and Douglas-fir with which it is commonly associated. Grand fir commonly outgrows the more tolerant western hemlock and western redcedar.

Grand fir has been planted successfully in many European countries, where it is considered one of the most potentially productive species (2). In England, growth of grand fir plantations was compared with that of neighboring plantations of other commonly planted species, and the rate of growth of grand fir at 40 years of age frequently equaled or exceeded that of other species such as Sitka spruce, Norway spruce (Picea abies), and Douglas-fir (2).

Grand fir seldom grows in pure stands except in areas of the Clearwater River drainage of north-central Idaho. Therefore, estimates of yields have value mainly in relation to mixed stands. Grand fir ranks among the most productive species in all the associations in which it grows. East of the Cascade crest in Oregon and Washington, yields of grand or white fir stands at age 100 years range from 476 to 1330 m³ /ha (6,800 to 19,000 ft³/acre) (4). In northern Idaho, where grand fir grows with western white pine, predicted yields of normal stands range from 470 to 1078 m/ha (6,720 to 15,400 W/acre) at age 100 (14). Estimates of mean annual growth range from 8 to 13 m³/ha (114 to 186 ft³/acre) in Idaho (27) and 6 to 10 m³/ha (86 to 143 ft³/acre) in Montana (23). On the more fertile soils of England, growth rates of 18 to 20 m³/ha (257 to 286 ft³/acre) to age 40 have been reported (2).

Grand fir is classed as shade-tolerant in all associations in which it occurs. In the Willamette Valley of Oregon, it is the climax type following Douglas-fir and Oregon white oak. In the Inland Empire it is more tolerant than any of its associates except western redcedar and western hemlock. It is the climax type on sites too dry for redcedar or hemlock. In coastal British Columbia, grand fir is similar to Sitka spruce in tolerance; that is, it is slightly more tolerant than Douglas-fir. It is the least shade-tolerant of the true firs in British Columbia and is much less tolerant than western hemlock, western redcedar, or Pacific silver fir. Grand fir is a versatile species that, although quite tolerant, has a growth rate nearly equal to that of western white pine.

Grand fir is a dominant climax species in some habitat types and a long-lived seral species in other types. It usually grows in mixed-species stands where either even-aged or uneven-aged silviculture is practiced. In the zone of genetic intergrade between grand and white fir, it is not possible to separate the two species and their hybrids visually. Silvicultural prescriptions and treatments are applied as if they were one species. Where grand fir is desired under even-aged management, shelterwood cuttings are preferred because regeneration and early growth are best in partial shade. It also regenerates satisfactorily on most sites, however, following seed tree or clearcutting (3,24). Following seedling establishment, the overstory should be removed to encourage rapid growth in height and diameter.

Under uneven-aged management, grand fir regenerates adequately and commonly outgrows the more tolerant western hemlock and western redcedar as an understory tree. Certain classes of understory grand fir saplings respond positively to release while others respond negatively (8,25). Pole-size and larger grand firs respond well to release by thinning and selection cuttings if the crowns are vigorous (13).

The grand fir root system is intermediate in development among its associated tree species. The anchoring taproot does not grow as rapidly nor as deeply as dry site associates such as ponderosa pine, Douglas-fir, and lodgepole pine, but it grows faster and deeper than wet site species such as western hemlock, western redcedar, and Engelmann spruce. Seedling roots penetrate the soil rapidly enough in full sunlight to survive drought conditions in duff and surface soil. Grand fir produces roots under shaded conditions, enabling it to survive in the understory. The adaptable root system contributes to the growth of grand fir over a wide range of sites and climatic conditions. A relatively deep taproot enables grand fir to survive and grow well on rather dry soils and exposed ridges. On moist sites, the taproot is largely replaced by more shallow lateral roots (9).

Seed production begins at about 20 years of age and increases with age, diameter, and vigor of the tree. Eight-year observations of permanent sample plots in Idaho show that grand fir produced the fewest seeds of the species associated with western white pine. Grand fir produced no good crops and only two fair crops, while western white pine produced two good crops and three fair crops. During the same 8-year period, western hemlock produced five good crops and two fair crops (9). In the coastal forests of Washington, grand fir ranked higher than western white pine and intermediate among upper slope species in number of seeds produced per tree (22). Other sources place the interval between good seed crops at 2 to 3 years (10,32).

In the Inland Empire, a good cone crop for grand fir is considered to be more than 40 cones per tree. A fair crop is 21 to 40 cones per tree. Grand fir seeds caught annually in seed traps on two sample plots averaged 42,000/ha (17,000 acre) on the Kaniksu National Forest and 58,100/ha (23,500 acre) on the Coeur d'Alene National Forest. Eight-year observations of seed traps under a 300-year-old stand on the Priest River Experimental Forest yielded 31,600 grand fir seeds per hectare (12,800 acre) annually (9). The yield of cleaned seeds ranges from 26,200 to 63,100/kg (11,900 to 28,700/lb) and averages 40,500/kg (18,400/lb) (32).

When the cones are ripe, the scales fall away and release the large-winged seeds, leaving only the central spike. Seeds are dispersed by the wind and rodents. Most of the seeds are disseminated in the early fall, about 5 percent falling before September 1 and 80 percent falling before the end of October. Seeds sufficient to produce adequate reproduction may be distributed up to 120 m (400 ft) from the parent tree, but the average distance is about 45 to 60 m (150 to 200 ft). Seeds in the duff remain viable through only one overwinter period (9).

Grand fir seeds germinate in the spring following one overwinter period on the ground. In natural stands, germination is quite variable but is seldom greater than 50 percent because of embryo dormancy, insect infestation, and the perishable nature of the seeds. Seeds are often so heavily infested with insects that an entire crop may be classed as a failure (9).

Stratification under cool, moist conditions speeds germination. Grand fir seeds are typically stratified at 1° to 5° C (34° to 41° F) for 14 to 42 days before nursery sowing in the spring. Results of greenhouse germination tests of grand fir seeds are highly variable. In three sandflat germination tests in the northern Rockies, grand fir had the lowest germination percentage among major associates of the western white pine type (9). Average percentages were grand fir, 12; western larch, 30; Douglas-fir, 41; western white pine, 44; western hemlock, 65; and western redcedar, 73. As with other true firs, germination is epigeal.

In reported tests, germinative capacity ranged from 0 to 93 percent and averaged 50 percent (32). The variability and average grand fir germination are about average for the true firs.

Grand fir seed germination begins in late April or early May on exposed sites and a month later on protected sites where snow lingers late. It is practically completed by July 1 on exposed sites and by August 15 on protected sites. Germination is best on mineral soil, but on seed-tree cuttings, grand fir germinates nearly as well on duff as on any other surface (9).

Studies of seedling survival indicate that more than 30 percent of grand fir seedlings die in the first season, and an additional 10 percent die in the second season. Losses drop off rapidly after the first 2 years, and seedlings 3 years old are fairly well established (9,24). Studies of mortality during the critical first year indicate that early season losses are due principally to biotic agents, especially damping-off fungi. Fungi-caused mortality is very irregular, however. Later in the season as the soil begins to dry and temperatures rise, mortality is due principally to heat from insolation and drought. Surface-soil temperatures are less important under shade or on sheltered sites, and under dense shade or on north slopes high temperatures do not cause death. Grand fir is relatively resistant to heat injury; it is equal to western white pine and Douglas-fir and more resistant than western larch, western hemlock, and western redcedar. Grand fir seedlings are relatively resistant to drought on areas exposed to full sun because deep initial root penetration protects them from drying of the surface soil. On heavily shaded, cool areas, drought is the most important physical cause of seedling mortality because initial root penetration is slow; even shallow drying of the surface soil may cause drought mortality despite ample soil moisture at deeper levels (9).

Initial survival and growth of grand fir are favored by a moderate overwood shade. Under full sun it is largely subordinate to faster growing, shade-intolerant species. Under partial overwood shade, grand fir is aggressive enough to form a dominant part of the reproduction. After 20 to 30 years, it makes most rapid growth in the open (9).

Grand fir seems to grow equally well on soils derived from a variety of parent materials, including sandstone, weathered lava (rock), or granite and gneiss. In the Pacific coast region and in the Willamette Valley of Oregon it grows most abundantly on deep, rich alluvial soils along streams and valley bottoms and on moist soils provided with seepage. In the inland regions it grows best on rich mineral soils of the valley bottoms, but it also grows well on shallow, exposed soils of mountain ridges and pure pumice soils in central and eastern Oregon, provided moisture is adequate (9). Most of the soils that support grand fir have been classified as Spodosols.

Grand fir grows on Vancouver Island and the adjacent mainland of British Columbia at elevations between sea level and 305 m (1,000 ft). In the southern interior of British Columbia it grows only in the moist valleys of such rivers as the Kootenay, Columbia, and Okanogan and their tributaries. Grand fir is predominantly a lowland species in western Washington, Oregon, and British Columbia. In western Washington it grows in valleys and stream bottoms having high ground-water levels. Elevations of these sites are usually between 180 and 305 m (590 and 1,000 ft). At elevations above 460 m (1,510 ft), grand fir is replaced by Pacific silver fir (Abies amabilis). Grand fir is found in western Oregon and in the lowlands of all the river regions, and in the lower west Cascades to an elevation of 915 m (3,000 ft). In northern California it grows from near sea level to about 1525 m (5,000 ft) (9).

In the eastern Cascades of Washington, 915 to 1220 m (3,000 to 4,000 ft) is the upper altitude limit for grand fir, while in the eastern Cascades of Oregon it grows at 1525 m (5,000 ft). In the Inland Empire, including the Blue Mountains of Oregon, it is found as high as 1830 m (6,000 ft) and as low as 460 m (1,500 ft), but usually between 610 and 1525 m (2,000 and 5,000 ft). In the Nez Perce region of central Idaho, it grows well at altitudes of 1220 to 1675 m (4,000 to 5,500 ft) (9).

The soft white wood of grand fir is a valued source of pulpwood. The wood also is commercially valuable as timber even though it is weaker and more prone to decay than many other species. The luxuriant foliage, symmetry, and deep green shiny color make grand fir one of the preferred species of Christmas trees grown in the Northwest. The attractive appearance of grand fir makes it valuable in recreation areas and urban plantings.

No information is currently available.

Grand fir grows in the stream bottoms, valleys, and mountain slopes of northwestern United States and southern British Columbia. Its wide geographical distribution is from latitude 51° to 39° N. and from longitude 125° to 114° W. In the Pacific coast region it grows in southern British Columbia mainly on the lee side of Vancouver Island and the adjacent mainland, in the interior valleys and lowlands of western Washington and Oregon, and in northwestern California as far south as Sonoma County. The range in the continental interior extends from the Okanogan and Kootenay Lakes in southern British Columbia south through eastern Washington, northern Idaho, western Montana west of the Continental Divide, and northeastern Oregon. The best commercial stands of grand fir are in the Nez Perce and Clearwater regions of northern Idaho (9).


- The native range of grand fir.

Pinaceae -- Pine family

Marvin W. Foiles, Russel T. Graham, and David F. Olson, Jr.

Grand fir (Abies grandis), also called lowland white fir, balsam fir, or yellow fir, is a rapid-growing tree that reaches its largest size in the rain forest of the Olympic Peninsula of Washington. One tree in that area measures 200 cm (78.9 in) in d.b.h., 70.4 m (231 ft) tall, and has a crown spread of 14 m (46 ft). The species also has historic significance. The famous Barlow Road snub-trees on the south side of Mount Hood in Oregon were grand firs. They were used by early settlers to control the rate of descent of their covered wagons on a particularly steep slope in their trek from east to west. Some of the rope-burned trees are still standing after 150 years.

Tree, Evergreen, Monoecious, Habit erect, Trees without or rarely having knees, Primary plant stem smooth, Tree with bark smooth, Tree with bark rough or scaly, Young shoots 3-dimensional, Buds resinous, Leaves needle-like, Leaves alternate, Needle-like leaf margins entire (use magnification), Leaf apex mucronulate, Leaves < 5 cm long, Leaves > 5 cm long, Leaves < 10 cm long, Leaves not blue-green, Leaves white-striped, Needle-like leaves flat, Needle-like leaves not twisted, Needle-like leaf habit erect, Needle-like leaf habit drooping, Needle-like leaves per fascicle mostly 1, Needle-like leaf sheath early deciduous, Needle-like leaf sheath persistent, Twigs pubescent, Twigs not viscid, Twigs without peg-like projections or large fascicles after needles fall, Berry-like cones orange, Woody seed cones > 5 cm long, Bracts of seed cone included, Seeds tan, Seeds winged, Seeds unequally winged, Seed wings prominent, Seed wings equal to or broader than body.

Abies grandis (grand fir, giant fir, lowland white fir, great silver fir, western white fir, Vancouver fir, or Oregon fir) is a fir native to the Pacific Northwest and Northern California of North America, occurring at altitudes of sea level to 1,700 metres (5,600 ft). It is a major constituent of the Grand Fir/Douglas Fir Ecoregion of the Cascade Range.

The tree typically grows to 40–70 m (130–230 ft) in height, and may be the tallest Abies species in the world. There are two varieties, the taller coast grand fir, found west of the Cascade Mountains, and the shorter interior grand fir, found east of the Cascades. It was first described in 1831 by David Douglas.

It is closely related to white fir. The bark was historically believed to have medicinal properties, and it is popular in the United States as a Christmas tree. Its lumber is a softwood, and it is harvested as a hem fir. It is used in paper-making, as well as construction for framing and flooring, where it is desired for its resistance to splitting and splintering.