Index of Species Information

SPECIES:  Abies amabilis


Introductory

SPECIES: Abies amabilis
AUTHORSHIP AND CITATION : Cope, Amy B. 1992. Abies amabilis. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [].

ABBREVIATION : ABIAMA SYNONYMS : NO-ENTRY SCS PLANT CODE : ABAM COMMON NAMES : Pacific silver fir amabilis fir Cascades fir lovely fir silver fir TAXONOMY : The currently accepted scientific name for Pacific silver fir is Abies amabilis (Doug) ex. Loud. Pacific silver fir does not hybridize with its true fir associates. Some morphological intermediates of Pacific silver fir and subalpine fir (Abies lasiocarpa) have been reported [42], but these have proved not to be hybrids [14]. LIFE FORM : Tree FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


DISTRIBUTION AND OCCURRENCE

SPECIES: Abies amabilis
GENERAL DISTRIBUTION : Pacific silver fir occurs from extreme southeastern Alaska south through western British Columbia, the Cascade Range of Washington and Oregon, to northwestern California [6,7,51,55,60]. Pacific silver fir is also found in the Olympic Mountains of Washington [6,7,38]. ECOSYSTEMS : FRES20 Douglas-fir FRES22 Western white pine FRES23 Fir - spruce FRES24 Hemlock - Sitka spruce STATES : AK CA OR WA BC BLM PHYSIOGRAPHIC REGIONS : 1 Northern Pacific Border 2 Cascade Mountains 4 Sierra Mountains KUCHLER PLANT ASSOCIATIONS : K001 Spruce - cedar - hemlock forest K002 Cedar - hemlock - Douglas-fir forest K003 Silver fir - Douglas-fir forest K004 Fir - hemlock forest K005 Mixed conifer forest K012 Douglas-fir forest K013 Cedar - hemlock - pine forest K014 Grand fir - Douglas-fir forest K015 Western spruce - fir forest SAF COVER TYPES : 205 Mountain hemlock 206 Engelmann spruce - subalpine fir 213 Grand fir 215 Western white pine 221 Red alder 223 Sitka spruce 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 SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Pacific silver fir commonly occurs in late seral or climax mixed-conifer stands [52]. Throughout its range the most commonly associated conifer is western hemlock (Tsuga heterophylla). Pacific silver fir also reportedly grows in extensive pure stands in parts of the southern Washington Cascade Range [14]. Below are publications in which Pacific silver fir is listed as a dominant or codominant species: Preliminary plant associations of the southern Oregon Cascade Province [9] Preliminary classification of forest communities in the central portion of the western Cascades in Oregon [16] Forest communities of Mount Rainier National Park [28] Plant association of Mount Hood and Willamette National Forests of Oregon [35] Forest communities of northern California [55] Plant associations for the western hemlock zone [64] Preliminary classification systems for the vegetation of Alaska [68].

MANAGEMENT CONSIDERATIONS

SPECIES: Abies amabilis
WOOD PRODUCTS VALUE : The wood of Pacific silver fir is soft, light in weight and color, and has little odor or resin [14,26]. The wood is weak and has low durability [26]. The most common uses of Pacific silver fir are light construction frames, subfloor, construction plywood, sheaths, container veneer, and pulpwood [14,24,26]. As a "white wood", Pacific silver fir is a major export to Japan for business construction [24]. It is used for Christmas trees and decorative greenery [14,24,26]. IMPORTANCE TO LIVESTOCK AND WILDLIFE : Old-growth stands provide good mountain goat habitat [70]. Northern spotted owls are dependent on the availability of old-growth stands for nest site selection and sufficient prey [54]. Other species with a preference for old-growth stands include Vaux's swift, fisher, western red-backed vole, and Olympic salamander [60]. Small nongame birds prefer late seral or old-growth Pacific silver fir stands [39]. The seeds of Pacific silver fir are eaten by birds, rodents, and squirrels [59,63]. Pacific silver fir is the least preferred of trees browsed by elk [33]. PALATABILITY : NO-ENTRY NUTRITIONAL VALUE : NO-ENTRY COVER VALUE : The dense growth of Pacific silver fir provides hiding, cover, and thermal protection for wildlife [22]. VALUE FOR REHABILITATION OF DISTURBED SITES : Pacific silver fir is a good choice among tree species for planting in watersheds and locations with large amounts of mountain snowpack [22,24,26,41]. It is also well suited for developments such as campgrounds and trails [28]. OTHER USES AND VALUES : Pacific silver fir is grown as an ornamental [51]. It is a major component of recreational and wilderness areas [14]. OTHER MANAGEMENT CONSIDERATIONS : Rotation periods for Pacific silver fir vary, depending on management objectives. For mountain goat habitat, the recommended rotation period is 90 to 110 years [70]. For other nontimber (i.e. recreational, etc.) benefits, the suggested rotation period is 150 to 200 years. Commercial rotations are seldom longer than 110 years [70]. After release by logging or windfall, suppressed trees respond with immediate and substantial growth [59]. At lower elevations in the Pacific silver fir zone, Pacific silver fir usually sun scalds when used as leave tree in shelterwood cuttings [26]. Sudden exposure to sunlight temporarily reduces growth. By the third season, the exposed trees are growing faster than those trees at the stand edge. As many as seven growing seasons may be needed for Pacific silver fir to reach maximum rates of branch and height growth [65]. The shade tolerance of Pacific silver fir makes it a good choice for the selection method. The disadvantage of this practice is that it appears to encourage disease [36]. The timing of cone collection (mid to late August) is important because cones disintegrate as they mature. Felling and topping are not successful collection methods. The cones are susceptible to molding and heat build-up if sacked when wet [18]. Calcid flies (Pregastigmus spp.) infect cones of Pacific silver fir [59]. Franklin [24] discusses a cone drying schedule and seed storage conditions. Seeds are delicate and their coats may be damaged when drying [16]. Edwards [17] reviews techniques of seed extraction, viability, and germination testing. Cleaned seeds range from 17,200 to 45,860 seeds per pound (7,800-20,800 seeds/kg) [14], and average 11,000 to 13,800 seeds per pound (4,590-6,210 seeds/kg) [24]. A stratification period of 21 to 28 days is required. Seeds should be sown in spring at a density of 62.5 to 125 per acre (25-50 per ha) and approximately 0.25 inch (0.64 cm) deep, depending on the site [24]. Arnott and Mathews [7] discuss nursery practice for Pacific silver fir. Highest stocking can be achieved on bare soil [34]. Seedlings planted in logged areas have done poorly [6]. Gessel and Klock [31] report that fertilizer contributes significantly to growth of Pacific silver fir on poor sites, but Packee and others [51] disagree. During the seedling stage when growth is slow, fertilizer may be more effective than during other stages [52]. The application of nitrates are more beneficial to Pacific silver fir than ammonia compounds [31,42,51]. Fertilizer combined with thinning results in accelerated volume and radial growth [31]. Herbicides have various effects on Pacific silver fir. The effect of glyphosate and granular and liquid hexazinone had little effect. 2,4-D ester, when applied at maximum rates in spring and late summer, had a moderate effect on Pacific silver fir. Triclopyr ester had no effect when applied in summer [10]. Pacific silver fir is damaged by mountain beaver, black bear, and porcupine, which increases susceptibility to pathogens [56]. Wounds result in wetwood, circular or radial shake, and frost cracks [3]. Pacific silver fir is among those species that are most seriously affected by annosus root disease (Heterobasidion annosum). The incidence of fungal infestations is higher in stands 200 years or older than in younger stands [14]. Often a rotation of 40 to 120 years and minimization of wounding trees will reduce intermediate entry of the pathogen [22]. Airborne infection of Pacific silver fir is high year-round [14]. Annosus root disease infects trees when roots grow in contact with infected fungus food base. Other trees become infected through root contacts. Air-borne spores colonize wounds up to 1 month old [62]. Trees with this fungus show butt rot, retarded leader growth, sparse and chloritic foliage, and distress cone crops; mortality may occur [22,55]. Young stands can have high infection levels with low severity damage [70]. The fungus and tree can "wall off" each other, but once the tree becomes weakened, the fungus will invade [22]. After being weakened by annosus root disease, infestation by fir-engraver beetle (Scolylus ventralis), silver fir beetle (Pseudohylesinus sericeus), or fir root bark beetle (Pseudohylesinus granulalus) is frequent [14,22,55]. When beetle populations are high, Pacific silver fir may be attacked and killed before symptoms of infection are found. These effects are enhanced during a drought [55]. Annosus root disease also causes stem decay [22]. The most reliable way to diagnose Annosus root disease is by the presence of conks, or fruiting bodies, found in the duff layer at the root collar on the outer bark. Ectotrophic mycelium on the roots cannot be used in diagnosing annosus root disease [55]. To prevent damage to trees during logging, options include using rubber-tired skidders, working with a proven crew, and afterwards, treating remaining stumps with a registered pesticide to prevent its use as a food source [62]. At the time of logging, stump removal to reduce innoculum in the soil is useful in preventing further contamination [62]. Borax application can be part of timber sales contracts when this treatment is considered appropriate [70]. Saplings and pole-sized trees are too small to be effective innoculum sources. Management should involve reducing mortality, thinning fir trees at least 25 feet (7.5 m) from dead trees, and minimizing wounding during salvage logging [22]. Armillaria (Armillaria ostoyae) is often a secondary pathogen of trees infected with annosus root disease [55]. Pacific silver fir is moderately susceptible to Armillaria. In stands with smaller trees, thinning those within 25 feet (7.5 m) of dead trees, reducing mortality, and minimizing wounding is helpful. Prescribed burning may slow Armillaria growth [22]. Shoestring rot (Armillaria mellea) is also detrimental to Pacific silver fir [14]. Fungi found in advance regeneration of Pacific silver fir are Indian paint fungus (Echinodontium tinctorium) and Stereum sanguinolentum [20]. Indian paint fungus has been located on healthy stems and encased branch piths of suppressed Pacific silver fir. Decay is commonly found near wounds [4]. Infection sites include small diameter branch stubs between 50 and 60 years of age [4]. Indian paint fungus has a dormant phase, which occurs when wounded tissues heal [4]. When trees receive a new injury, the fungus resumes growth [3]. Indian paint fungus is most easily recognized by the presence of conks or slow decay in old large wounds [22]. Stand rotation should be 150 years or less and wound reduction activities should be practiced [22]. Filip and Schmitt [2] discuss color recognition of Indian paint fungus and planning and operational activities. Pacific silver fir is moderately susceptible to laminated root rot (Phellinus weirii), which creates forest patches of damaged or dead trees when abundant [15]. Infected trees in sawtimber-sized stands should be removed, followed with stump removal or replacement with disease-tolerant species. Air-drying the stumps kills the fungi. Fire is ineffective against annosus root disease, Armillaria, and laminated root rot [56]. Potebniamyces dieback (Phacidium balsamicola) causes small branch dieback and swelling at the girdling point but does not cause significant losses. Treatment involves spacing severely infected trees at precommercial thinning levels. For white-spored rusts (Uredinopsis spp.), site preparation procedures should avoid encouraging the growth of alternate hosts. In severe cases, it may be necessary to apply herbicide to alternate hosts. There is no management practice known for Virgilla robusta and Abies rust (Pucciniatrum spp.), except to minimize the number of alternate hosts of Abies rust during site preparation. Other fungi prevalent in fir stands include Caloscypha fulgens, Sirococcus blight, and Sirococcus strobilinus [62]. Pacific silver fir is also susceptible to western spruce budworm (Choristeneura occidentalis), Douglas-fir tussock moth (Orygia pseudotsugata), and fir-engraver beetle [22,35]. The effects of these pests can be alleviated by the application of fertilizer, and minimized by variation of stand structure and by planting pest-tolerant species [22]. At sites of western spruce budworm infestation, treatment should decrease the number of vulnerable trees and should increase the number of young trees by lowering maximum tree sizes. Ambrosia beetles (Trypodendron lineatum and Gnathotrichus sulcatus) can be captured with pheromone, multifunnel traps in late June when the beetles are flying. Harvesting should be planned so that logs are not left on the ground to be attacked by ambrosia beetles [45]. One of the most devastating pests to Pacific silver fir is balsam woolly aphid (Adelges piceae) [14,57]. Infested trees appear swollen, with gouty twigs, poor crowns, and little growth; death occurs within 2 to 3 years [22]. Infested trees have mottled-red foliage, distinct "crown lean", and appear to die from the top down. Trees greater than 28 inches (71 cm) in d.b.h. sustain the most damage among the dominant crown classes [29]. In order to protect nearby stands, the advance regeneration must be destroyed and the site should be returned to a seral habitat, such as western hemlock [56]. Pacific silver fir is a secondary host for dwarf mistletoe (Arceuthobium tsugense and Arceuthobium abietinum) [14]. Dwarf mistletoes cause growth loss and tree mortality when in association with canker fungi (Cytospora abietis). The key management practices should be detection, evaluation, prevention, and suppression. Living infected residues should be killed before susceptible regeneration reaches 3 feet (0.9 m) or 10 years of age [22]. Ruth [57] suggests removing the overstory and burning seedlings and other residue material in seedling infected stands. Slash burning may be one of the most effective tools to eliminate dwarf mistletoe. Special site preparation and herbicides may also be useful tools for treatment [56].

BOTANICAL AND ECOLOGICAL CHARACTERISTICS

SPECIES: Abies amabilis
GENERAL BOTANICAL CHARACTERISTICS : Pacific silver fir is a monoecious, long-lived, native conifer [14,24,38,66,68]. At maturity, it can reach heights of 100 to 230 feet (30-70 m) and diameters of 36 to 44 inches (90-110 cm) [24,26,38]. The average maximum age for Pacific silver fir is 400 to 500 years on good sites, and 250 to 350 years on more adverse sites. The maximum recorded age is 540 years [14,59]. As Pacific silver fir becomes older, growth is commonly deformed [57]. The crown is rigid and symmetrical with lateral branches perpendicular to the stem [14]. Young trees have resin-filled blisters protruding from the smooth, thin bark. The bark of older trees is rough textured and flaky [6]. The needles grow from opposite sides of the branch, spreading horizontally or brushed forward. The top is flat, grooved, and "lustrous green", and the underside is stomatiferous and silvery white [6,38]. Pacific silver fir has a second type of foliage on the uppermost, cone-bearing branches. These needles are very sharp and curved. The cones are stiffly erect, barrel shaped, and 3.5 to 6 inches (8.9-15.2 cm) long [6]. RAUNKIAER LIFE FORM : Phanerophyte REGENERATION PROCESSES : Pacific silver fir reproduces only from seed [14]. Seed production begins at 20 to 30 years of age [14]. There are approximately 400 seeds per cone; percentage of sound seed ranges from 6.3 to 35 percent [14,24]. Good seed crops are generally produced every 2 to 3 years [14,59], but intervals between good seed crops may be as long as 6 years according to some reports [17,25]. Production of seed is poor due to the high frequency of low pollen production years [14]. Complete crop failures sometimes occur [59]. Pacific silver fir requires 2 years to complete its reproductive cycle [63]. It is capable of self-fertilization [14,38]. Wind dispersion of seed is inefficient because of seed size and cone disintegration [59]. Germination occurs in the spring. Germination can occur on a variety of substrates such as litter, rotten wood, moss, organic and mineral soils, and fresh volcanic tephra. Cool, moist sites are optimal for germination, but full sunlight produces maximum growth [14]. Pacific silver fir takes 9 years to reach breast height on average sites [14], 5 to 9 years on more favorable sites, and up to 80 years when severely suppressed [36]. SITE CHARACTERISTICS : The climate throughout the range of Pacific silver fir is maritime to submaritime [14,41]. Pacific silver fir is usually submontane to subalpine [27,41]. It thrives in areas that receive a great deal of precipitation. Average annual precipitation ranges between 38 and 262 inches (965-6650 mm), mostly in the form of snow [14,22,27,42]. The average winter temperature is 26 to 29.8 degrees Fahrenheit (-3.2 to -1.7 deg C), and the average summer temperature is 57.2 to 58.8 degrees Fahrenheit (14-14.9 deg C) [14,71]. Pacific silver fir is absent in coastal areas with dry summers [59]. There is a correlation between growth, snow-free period, days above a certain temperature, absence of frost pockets, and preferable sites for Pacific silver fir [32]. Pacific silver fir has a mild frost tolerance and poor frozen soil tolerance because of its need for water during the winter [22,51]. Pacific silver fir is an indicator of very moist soils. It occurs on soils in the orders Alfisols, Entisols, Inceptisols, Histosols, and Spodosols [51,67]. Soil parent materials include basalt, glacial till, volcanic ash, pumice, and sedimentary rock [31,51,52]. Pacific silver fir can grow where the water table is near the surface during the growing season if the soil is well aerated, thick, and/or with wood accumulations on top of the mineral soil [59]. Growth is successful with thick humus present [59]. Soils are generally shallow, but soil depth varies from 1.2 to 12 inches (3-30 cm) [27]. Soils are acidic in the rooting zone (pH 5) [41]. Whatever the soil type, an adequate, year-round water supply is very important. Often nitrogen and occassionally sulfur are limiting elements in soils [32]. Soils rich in magnesium and calcium indicate good sites for Pacific silver fir [42]. The elevation at which Pacific silver fir grows is quite variable. It is more common at higher elevations but grows faster at lower elevations [59]. Pacific silver fir occurs at a maximum of 7,000 feet (2,120 m) in the southern part of its range and at a maximum of 1,000 feet (330 m) in the northern part of its range [14,22,24,27,51]. Overstory associates not mentioned in Distribution and Occurrence include noble fir (Abies procera), Alaska cedar (Chamaecyparis nootkatensis), Shasta red fir (Abies magnifica var. shastensis), and western larch (Larix occidentalis) [9.14,27,51,60]. Shrub understory includes huckleberry (Vaccinium spp.), Cascades azalea (Rhododendron albiflorum), devils club (Oplopanax horridum), copper bush (Cladothanus pyrolaeflorus), rustyleaf menziesia (Menziesia ferruginea), salal (Gaultheria shallon), vine maple (Acer circatum), and Oregon-grape (Berberis nervosa) [9,12,15,28,52]. Herbaceous species are beargrass (Xerophyllum tenax), bunchberry (Cornus canadensis), twinflower (Linnea borealis), queenscup beadlily (Clintonia uniflora), dwarf blackberry (Rubus lasiococcus), rosy twistedstalk (Streptopus roseus), coolwort foamflower (Tiarella unifoliata), deer fern (Blechnum spicant), salmonberry (Rubus spectabilis), vanillaleaf (Achlys spp.), and evergreen violet (Viola sempervirens) [9,12,14,28,52]. SUCCESSIONAL STATUS : Obligate Climax Species Pacific silver fir is a late seral or climax species in most habitats [41]. In the mountain hemlock zone, Pacific silver fir succeeds species such as Shasta red fir, subalpine fir, and grand fir [27]. Pacific silver fir is very shade tolerant and has low spatial requirements [14,15,22,26,71]. Pacific silver fir can survive in the shade and emerge in stands that are uneven-aged [51]. Due to ineffecient dispersion of seed by wind, migration is slow [56]. Following disturbance, Douglas-fir and noble fir become established. Pacific silver fir is the last to invade, sometimes 400 to 500 years after the disturbance. After extensive forest fires, Pacific silver fir may not become important among the large trees for 700 to 800 years [61,69]. Eventually, Douglas-fir and noble fir fail to reproduce [27]. Often, almost all understory species are eliminated by shade, resulting in an open forest floor [51]. Pacific silver fir is common in mixed stands and rare in even-aged stands [59]. SEASONAL DEVELOPMENT : Pacific silver fir has a 2-year reproductive cycle. In May of the first year, buds are initiated; differentiation follows in July. Megagametophytes and ovuliferous scales are initiated in mid-July and mid-August, respectively. Both are dormant by November and remain dormant until April of the second year, at which time development of the pollen-cone and seed-cone buds is resumed [63]. Pollination occurs in May and is well synchronized with female receptivity [14,63]. Fertilization occurs in early July, 4 to 5 weeks after pollination. In early August, meristems and cotyledons of embryos develop and mature by the end of the month. Cones change from green to purple at maturity [6,63]. As cones mature, they disintegrate before the seed can be dispersed, which occurs in September and October [24,63]. Germination occurs in the spring [14]. Juvenile growth ranges from 4 to 16 inches (10-40 cm) per year [14]. Advance regeneration is quite sturdy but grows slowly. Terminal growth averages 19.9 (49.7 cm) per year [14].

FIRE ECOLOGY

SPECIES: Abies amabilis
FIRE ECOLOGY OR ADAPTATIONS : In the Pacific silver fir zone, fires are infrequent (fire interval is 500 years) because of the humidity and the high levels of precipitation. Surface fires are usually of low severity [69]. Some stands of Pacific silver fir show no evidence of having burned. Fire frequency is a limiting factor in the range of Pacific silver fir [69]. Pacific silver fir is a fire-avoiding species throughout all stages of its life [72]. It is extremely fire sensitive primarily because its thin bark and shallow roots [26]. Its foliage is highly flammable [50]. The mean fire interval for Pacific silver fir as a primary dominant is 192 years [1]. FIRE REGIMES : Find 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". POSTFIRE REGENERATION STRATEGY : Tree without adventitious-bud root crown Secondary colonizer - off-site seed

FIRE EFFECTS

SPECIES: Abies amabilis
IMMEDIATE FIRE EFFECT ON PLANT : Pacific silver fir has a low fire tolerance and is usually killed by any forest fire [6,50,69]. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : Pacific silver fir germinates on exposed mineral soils, but its seed often travels only a short distance onto the site [56]. Burned soils have radical temperature fluctuations, which may prevent Pacific silver fir from establishing on burned sites. One year after the 1978 Hoh fire in the Olyumpic Mountains, Pacific silver fir seedlings were found at a great concentration, but they did not appear as healthy as other seedlings [2]. Slash burning increases the time for Pacific silver fir to reach 60 percent stocking rate [23]. DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : NO-ENTRY FIRE MANAGEMENT CONSIDERATIONS : Slash burning and stump removal decrease site preparation cost [56] but have considerable repercussions. Slash burning has negative effects on higher elevation ecosystems because of their low productivity and the difficulty of replanting [57]. It also destroys advance regeneration and delays natural regeneration [23]. Ruth [57] states, "it is good insurance" to protect advance regeneration in these higher elevation stands. These areas have a short burning season. Miller and Bigley [46] found that slash burning decreases the number of conifers, including Pacific silver fir. Logging of Pacific silver fir leaves a high residue volume which can become a high fire hazard. Some ways to reduce slash loadings and fire hazard are to cut lower volume or younger stands, and use more volume or yard cull logs to encourage utilization (which is currently practiced on federal lands). These practices may reduce the effects of slash burning on site productivity and stand development [46].

REFERENCES

SPECIES: Abies amabilis
REFERENCES : 1. Agee, James K.; Finney, Mark; DeGouvenain, Roland. 1990. Forest fire history of Desolation Peak, Washington. Canadian Journal of Forest Research. 20: 350-356. [11035] 2. Agee, James K.; Smith, Larry. 1984. Subalpine tree reestablishment after fire in the Olympic Mountains, Washington. Ecology. 65(3): 810-819. [6102] 3. Aho, Paul E. 1982. Decay problems in true fir stands. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest symposium; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 203-207. [6866] 4. Aho, P. E.; Filip, G. M. 1982. Incidence of wounding and Echinodontium tinctorium infection in advanced white fir regeneration. Canadian Journal of Forest Research. 12(3): 705-708. [7919] 5. Aller, Alvin R. 1956. A taxonomic and ecological study of the flora of Monument Peak, Oregon. American Midland Naturalist. 56(2): 454-472. [6385] 6. Arno, Stephen F.; Hammerly, Ramona P. 1977. Northwest trees. Seattle, WA: The Mountaineers. 222 p. [4208] 7. Arno, Stephen F.; Hammerly, Ramona P. 1984. Timberline: Mountain and arctic forest frontiers. Seattle, WA: The Mountaineers. 304 p. [339] 8. Arnott, J. T.; Matthews, R. G. 1982. Nursery production of true firs in British Columbia. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest symposium; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 195-201. [6865] 9. Atzet, Thomas; McCrimmon, Lisa A. 1990. Preliminary plant associations of the southern Oregon Cascade Mountain Province. Grants Pass, OR: U.S. Department of Agriculture, Forest Service, Siskiyou National Forest. 330 p. [12977] 10. Balfour, Patty M. 1989. Effects of forest herbicides on some important wildlife forage species. Victoria, BC: British Columbia Ministry of Forests, Research Branch. 58 p. [12148] 11. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434] 12. Brockway, Dale G.; Topik, Christopher; Hemstrom, Miles A.; Emmingham, William H. 1985. Plant association and management guide for the Pacific silver fir zone: Gifford Pinchot National Forest. R6-Ecol-130a. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 122 p. [525] 13. Carkin, Richard E.; Franklin, Jerry F.; Booth, Jack; Smith, Clark E. 1978. Seeding habits of upper-slope tree species. IV. Seed flight of noble fir and Pacific silver fir. Res. Note PNW-312. Portland, OR: U.S. Department of Agriculture, Forest Service. 10 p. [7520] 14. Lane, Richard D. 1959. Managing young stands for quality production. In: What's known about managing eastern white pine. Stn. Pap. No. 121. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station: 45-55. [13664] 15. Dickman, Alan; Cook, Stanton. 1989. Fire and fungus in a mountain hemlock forest. Canadian Journal of Botany. 67(7): 2005-2016. [13015] 16. Dyrness, C. T.; Franklin, J. F.; Moir, W. H. 1974. A preliminary classification of forest communities in the central portion of the western Cascades in Oregon. Bulletin No. 4. Seattle, WA: University of Washington, Ecosystem Analysis Studies, Coniferous Forest Biome. 123 p. [8480] 17. Edwards, D. G. W. 1986. Cone prediction, collection, and processing. In: Shearer, Raymond C., compiler. Proceedings--conifer tree seed in the Inland Mountain West symposium; 1985 August 5-6; Missoula, MT. Gen. Tech. Rep. INT-203. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 78-102. [12784] 18. Ryan, Michael G.; Covington, W. Wallace. 1986. Effect of a prescribed burn in ponderosa pine on inorganic nitrogen concentrations of mineral soil. Res. Note RM-464. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 5 p. [11984] 19. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905] 20. Filip, Gregory M. 1989. A model for estimating current & future timber vol. loss from stem decay caused by Heterobasidion annosum and other fungi in stands of true fir. In: Otrosina, William J.; Scharpf, Robert F., technical coordinators. Proceedings of the symposium on research and management of annosus root disease (Heterobasidion annosum) in western North America; 1989 April 18-21; Monterey, CA. Gen. Tech. Rep. PSW-116. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 123-128. [11331] 21. Filip, Gregory M.; Hoffman, James T. 1991. Root disease management in western-montane forest soils. In: Harvey, Alan E.; Neuenschwander, Leon F., compilers. Proceedings--management and productivity of western-montane forest soils; 1990 April 10-12; Boise, ID. Gen. Tech. Rep. INT-280. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 167-170. [15981] 22. Filip, Gregory M.; Schmitt, Craig L. 1990. Rx for Abies: silvicultural options for diseased firs in Oregon and Washington. Gen. Tech. Rep. PNW-GTR-252. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 34 p. [15181] 23. Feller, M. C. 1983. Impacts of prescribed fire (slashburning) on forest productivity, soil erosion, and water quality on the coast. In: Trowbridge, R. L.; Macadam, A, eds. Prescribed fire- forest soils, symposium proceedings; 1982 March 2-3; Smithers, BC. Land Management Report Number 16. Victoria, BC: Province of British Columbia, Ministry of Forests: 57-91. [8852] 24. Franklin, Jerry F. 1974. Abies Mill. fir. In: Schopmeyer, C. S., technical coordinator. Seeds of woody plants in the United States. Agric. Handb. 450. Washington, DC: U.S. Department of Agriculture, Forest Service: 168-183. [7566] 25. Franklin, Jerry Forest. 1966. Vegetation and soils in the subalpine forests of the southern Washington Cascade Range. Pullman, WA: Washington State University. 132 p. Thesis. [10392] 26. Franklin, Jerry F. 1982. The true fir resource. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 1-6. [6600] 27. Franklin, Jerry F.; Dyrness, C. T. 1973. Natural vegetation of Oregon and Washington. Gen. Tech. Rep. PNW-8. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 417 p. [961] 28. Baker, Frederick S. 1944. Mountain climates of the western United States. Ecological Monographs. 14(2): 223-254. [12932] 29. Gara, Robert I. 1982. Insect pests of true firs in the Pacific Northwest. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest symposium; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 157-159. [6771] 30. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998] 31. Gessel, S. P.; Klock, G. O. 1983. Mineral nutrition of true fir. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest symposium; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 77-83. [6764] 32. Gessel, Stanley P.; Oliver, Chadwick Dearing. 1982. Soil-site relationships and productivity of true firs. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest symposium; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 177-184. [6864] 33. Gockerell, E. C. 1966. Plantations on burned versus unburned areas. Journal of Forestry. 64(6): 392-394. [6430] 34. Halverson, Nancy M.; Emmingham, William H. 1982. Reforestation in the Cascades Pacific silver fir zone; a survey of sites and management experiences on the Gifford Pinchot, Mt. Hood and Willame. U.S. Department of Agriculture Forest Service R-6 Area Guide R6-ECOL-091-1982. Pacific Northwest Region, Portland, Oregon 37 p. [12491] 35. Hemstrom, Miles A.; Franklin, Jerry F. 1982. Fire and other disturbances of the forests in Mount Rainier National Park. Quaternary Research. 18: 32-51. [6747] 36. Stanek, W.; Alexander, K.; Simmons, C. S. 1981. Reconnaissance of vegetation and soils along the Dempster Highway, Yukon Territory: I. Vegetation types. BC-X-217. Victoria, BC: Environment Canada, Canadian Forestry Service, Pacific Forest Research Centre. 32 p. [16526] 37. Vogt, Kristiina; Grier, Charles. 1983. Root growth and mycorrhizae in true firs. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest symposium; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 97-101. [6767] 38. Hitchcock, C. Leo; Cronquist, Arthur. 1973. Flora of the Pacific Northwest. Seattle, WA: University of Washington Press. 730 p. [1168] 39. Huff, Mark H.; Manuwal, David A.; Putera, Judy A. 1991. Winter bird communities in the southern Washington Cascade Range. In: Ruggiero, Leonard F.; Aubry, Keith B.; Carey, Andrew B.; Huff, Mark H., technical coordinators. Wildlife and vegetation of unmanaged Douglas-fir forests. Gen. Tech. Rep. PNW-GTR-285. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: 207-218. [17314] 40. Klaehn, F. U.; Winieski, J. A. 1962. Interspecific hybridization in the genus Abies. Silvae Genetica. 11: 130-142. [13494] 41. Klinka, K.; Krajina, V. J.; Ceska, A.; Scagel, A. M. 1989. Indicator plants of coastal British Columbia. Vancouver, BC: University of British Columbia Press. 288 p. [10703] 42. Krajina, V. J.; Klinka, K.; Worrall, J. 1982. Distribution and ecological characteristics of trees and shrubs of British Columbia. Vancouver, BC: University of British Columbia, Department of Botany and Faculty of Forestry. 131 p. [6728] 43. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384] 44. Lyon, L. Jack; Stickney, Peter F. 1976. Early vegetal succession following large northern Rocky Mountain wildfires. In: Proceedings, Tall Timbers fire ecology conference and Intermountain Fire Research Council fire and land management symposium; 1974 October 8-10; Missoula, MT. No. 14. Tallahassee, FL: Tall Timbers Research Station: 355-373. [1496] 45. McLean, John A.; Salom, Scott M. 1989. Relative abundance of ambrosia beetles in an old-growth western hemlock/ Pacific silver fir forest and adjacent harvesting areas. Western Journal of Applied Forestry. 4(4): 132-136. [9235] 46. Miller, Richard E.; Bigley, Richard E. 1990. Effects of burning Douglas-fir logging slash on stand development and site productivity. In: Gessel, S. P.; Lacate, D. S.; Weetman, G. F.; Powers, R. F, eds. Sustained productivity of forest soils: Proceedings, 7th North American soils conference; [Date of conference unknown]; [Location of conference unknown]. Vancouver, BC: University of British Columbia, Faculty of Forestry: 362-375. [15431] 47. Minore, Don. 1986. Germination, survival, and early growth of conifer seedlings in two habitat types. PNW-348. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 25 p. [12490] 48. Minore, Don;Dubrasich, Michael E. 1981. Regeneration after clearcutting in subalpine stands near Windigo Pass, Oregon. Journal of Forestry. September: 619-621. [6239] 49. Morris, William G. 1958. Influence of slash burning on regeneration, other plant cover, and fire hazard in the Douglas-fir region (A progress report). Res. Pap. PNW-29. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 49 p. [4803] 50. Parminter, John. 1983. Fire history and fire ecology in the Prince Rupert Forest region. In: Trowbridge, R. L.; Macadam, A., eds. Prescribed fire--forest soils: Symposium proceedings; 1982 March 2-3; Smithers, BC. Land Management Report Number 16. Victoria, BC: Province of British Columbia, Ministry of Forests: 1-35. [8849] 51. Packee, Edward C.; Oliver, Chadwick Dearing; Crawford, Peggy D. 1983. Ecology of Pacific silver fir. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest symposium; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 19-34. [6754] 52. Radwan, M. A.; Murray, M. D.; Kraft, J. M. 1989. Growth and foliar nutrient concentrations of Pacific silver fir. Canadian Journal of Forest Research. 19: 1429-1435. [9847] 53. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843] 54. Ripple, William J.; Johnson, David H.; Hershey, K. T.; Meslow, E. Charles. 1991. Old-growth and mature forests near spotted owl nests in western Oregon. Journal of Wildlife Management. 55(2): 316-318. [15164] 55. Aho, Paul E. 1977. Decay of grand fir in the Blue Mountains of Oregon and Washington. Res. Pap. PNW-229. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 18 p. [14235] 56. Russell, Kenelm W.; Thies, Walter G.; Campbell, Dan L.; [and others]. 1989. Effects of slash burning on forest damage from animals, insects, diseases, and adverse environment. In: Hanley, Donald P.; Kammenga, Jerry J.; Oliver, Chadwick D., eds. The burning decision: Regional perspectives on slash: Proceedings of the symposium; 1988 April 5-7; Seattle, WA. Contribution No. 66. Seattle, WA: University of Washington, College of Forest Research: 95-112. [11926] 57. Ruth, Robert H. 1974. Regeneration and growth of west-side mixed conifers. In: Camer, Owen P., ed. Environmental effects of forest residues in the Pacific Northwest: A state-of-knowledge compendium. Gen. Tech. Rep. PNW-24. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific NorthwestForest and Range Experiment Station: K-1 to K-21. [6381] 58. Schmitt, Craig L. 1989. Diagnosis of annosus root disease in mixed conifer forests in the northwestern United States. In: Otrosina, William J.; Scharpf, Robert F., technical coordinators. Proceedings of the symposium on research and management of annosus root disease (Heterobasidion annosum) in western North America; 1989 April 18-21; Monterey, CA. Gen. Tech. Rep. PSW-116. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 40-42. [11320] 59. Schmidt, R. G. 1957. The silvics and plant geography of the genus Abies in the coastal forests of British Columbia. Tech. Publ. T.46. Victoria, BC: British Columbia Department of Lands and Forests, British Columbia Forest Service. 31 p. [14237] 60. Spies, Thomas A.; Franklin, Jerry F. 1988. Old growth and forest dynamics in the Douglas-fir region of western Oregon and Washington. Natural Areas Journal. 8(3): 190-201. [7248] 61. Spies, Thomas A; Franklin, Jerry F. 1989. Gap characteristics and vegetation response in coniferous forests of the Pacific northwest. Ecology. 70(3): 543-545. [11395] 62. Sutherland, J. R.; Hunt, R. S. 1990. Diseases in reforestation. In: Lavender, D. P.; Parish, R.; Johnson, C. M.; [and others], eds. Regenerating British Columbia's forests. Vancouver, BC: University of British Columbia Press: 267-278. [10720] 63. Tanaka, Yasuomi. 1982. Biology of Abies seed production. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest symposium; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 103-111. [6768] 64. Topik, Christopher; Halverson, Nancy M.; Brockway, Dale G. 1986. Plant association and management guide for the western hemlock zone: Gifford Pichot National Forest. R6-ECOL-230A. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 132 p. [2351] 65. Tucker, Gabriel, F.; Hinckley, Thomas M.; Leverenz, Jerry; Jiang, Shi-Mei. 1987. Adjustments of foliar morphology in the acclimation of understory Pacific silver fir following clearcutting. Forest Ecology and Management. 21: 249-268. [11050] 66. U.S. Department of Agriculture, Soil Conservation Service. 1982. National list of scientific plant names. Vol. 1. List of plant names. SCS-TP-159. Washington, DC. 416 p. [11573] 67. Ugolini, F. C. 1982. Soil development in the Abies amabilis zone of the central Cascades, Washington. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest symposium; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 165-173. [6863] 68. Viereck, L. A.; Dyrness, C. T.; Batten, A. R.; Wenzlick, K. J. 1992. The Alaska vegetation classification. Gen. Tech. Rep. PNW-GTR-286. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 278 p. [2431] 69. Houston, C. Stuart; Scott, Frank. 1992. The effect of man-made platforms on osprey reproduction at Loon Lake, Saskatchewan. Journal of Raptor Research. 26(3): 152-158. [18439] 70. Young, Elvira. 1989. Management of westside Washington conifer stands infected with Heterobasidion annosum. In: Otrosina, William J.; Scharpf, Robert F., technical coordinators. Proceedings of the symposium on research and management of annosus root disease (Heterobasidion annosum) in western North America; 1989 April 18-21; Monterey, CA. Gen. Tech. Rep. PSW-116. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 150-152. [11334] 71. Zobel, Donald B.; Antos, Joseph A. 1991. Growth and development of natural seedlings of Abies and Tsuga in old-growth forest. Journal of Ecology. 70: 985-998. [18363] 72. Agee, James K. 1991. Fire history of Douglas-fir forests in the Pacific Northwest. In: Ruggiero, Leonard F.; Aubry, Keith B.; Carey, Andrew B.; Huff, Mark H., technical coordinators. Wildlife and vegetation of unmanaged Douglas-fir forests. Gen. Tech. Rep. PNW-GTR-285. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: 25-33. [17303]