Index of Species Information

SPECIES:  Abies balsamea


SPECIES: Abies balsamea
AUTHORSHIP AND CITATION : Uchytil, Ronald J. 1991. Abies balsamea. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [].
ABBREVIATION : ABIBAL SYNONYMS : NO-ENTRY SCS PLANT CODE : ABBA COMMON NAMES : balsam fir balsam Canadian balsam Canada balsam eastern fir bracted balsam fir blister fir TAXONOMY : The currently accepted scientific name of balsam fir is Abies balsamea (L.) Mill [32]. The genus Abies consists of about 40 species of evergreen trees found in the Northern Hemisphere. Nine Abies species, including balsam fir, are native to the United States. Balsam fir is widely distributed and exhibits geographic variation. Two varieties based on morphological differences are recognized [47]: var. balsamea var. phanerolepis Fern. Balsam fir is closely related to Fraser fir (A. fraseri). These species are probably relicts of an ancestral taxon which exhibited north-south clinal variation [24]. Trees in Virginia and West Virginia are possibly hybrids between these two species [32]. Some authorities recognize Fraser fir as a variety of balsam fir: A. b. var. fraseri [21]. Balsam fir hybridizes with subalpine fir (A. lasiocarpa) where their ranges overlap in the Canadian Rockies [24]. LIFE FORM : Tree FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


SPECIES: Abies balsamea
GENERAL DISTRIBUTION : Balsam fir is widely distributed in northeastern North America. It occurs from Newfoundland west across northern Quebec, northern Ontario, central Manitoba, and Saskatchewan to northwestern Alberta, south about 400 miles (640 km) to central Alberta, southeast to northern Minnesota and Wisconsin, and east to New England [21]. In the United States, scattered populations occur in southern Minnesota, southern Wisconsin, northeastern Iowa, Pennsylvania, West Virginia, and northern Virginia. The two varieties are distributed as follows [5]: var. balsamea - from Newfoundland and Labrador west to northeastern Alberta and south to Minnesota, Wisconsin, southern Ontario, northern Pennsylvania, New York, and New England. It is local in northeastern Iowa. var. phanerolepis - from Newfoundland and Labrador to Ontario and Maine and in the high mountains of New Hampshire, Vermont, and New York. It is also common in the higher mountains of Virginia and West Virginia. ECOSYSTEMS : FRES10 White - red - jack pine FRES11 Spruce - fir FRES18 Maple - beech - birch FRES19 Aspen - birch STATES : CT IA ME MA MI MN NH NY PA VT VA WV WI AB LB MB NB NF NS ON PE PQ SK BLM PHYSIOGRAPHIC REGIONS : NO-ENTRY KUCHLER PLANT ASSOCIATIONS : K093 Great Lakes spruce - fir forest K095 Great Lakes pine forest K096 Northeastern spruce - fir forest K107 Northern hardwoods - fir forest K108 Northern hardwoods - spruce forest SAF COVER TYPES : 1 Jack pine 5 Balsam fir 12 Black spruce 13 Black spruce - tamarack 15 Red pine 16 Aspen 17 Pin cherry 18 Paper birch 21 Eastern white pine 22 White pine - hemlock 23 Eastern hemlock 24 Hemlock - yellow birch 25 Sugar maple - beech - yellow birch 26 Sugar maple - basswood 30 Red spruce - yellow birch 31 Red spruce - sugar maple - beech 32 Red spruce 33 Red spruce - balsam fir 35 Paper birch - red spruce - balsam fir 37 Northern white cedar 38 Tamarack 39 Black ash - American elm - red maple 60 Beech - sugar maple 107 White spruce 108 Red maple 201 White spruce 202 White spruce - paper birch 204 Black spruce 251 White spruce - aspen 253 Black spruce - white spruce SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Balsam fir is more commonly found in mixed than in pure stands. It does occurs as a dominant species in pure stands in Newfoundland, Ontario, and Quebec. Its importance as a major forest tree declines west of Manitoba [5]. Balsam fir is a principal tree of boreal mixed stands in Canada, where it occurs with paper birch (Betula papyrifera), aspen (Populus tremuloides), black spruce (Picea mariana), and white spruce (P. glauca) [46]. In the Lake States, climax stands of balsam fir are relatively uncommon [21,45]. In Maine, balsam fir forms pure stands on flats between swamps and uplands [5]. In the Adirondacks, balsam fir sometimes dominates upper slopes above 3,200 feet (975 m) [5]. In New England and the Lake States, balsam fir is more commonly found in mixed stands, especially in forests dominated by black spruce, red spruce (Picea rubens), white spruce, eastern hemlock (Tsuga canadensis), northern white-cedar (Thuja occidentalis), paper birch, aspen, and red maple (Acer rubrum) [5,30,45]. Balsam fir is listed as a dominant part of the vegetation in the following community type (cts) and ecosystem (eas) classifications: Area Classification Authority PQ: Gaspe Peninsula forest veg. cts Zoladeski 1988 ON forest eas Jones & others 1983


SPECIES: Abies balsamea
WOOD PRODUCTS VALUE : Balsam fir wood is used primarily for pulpwood and lumber for light frame construction. It is also used extensively for cabin logs. The wood is lightweight, relatively soft, low in shock resistance, and has good splitting resistance. Balsam fir is not well suited for use as posts and poles because it decays rapidly. Minor wood products include paneling, crates, and other products not requiring high structural strength [5,21]. IMPORTANCE TO LIVESTOCK AND WILDLIFE : Balsam fir is a major food of moose during winter. It tends to be utilized more when snow is deep and moose populations are high [41]. Moose may browse balsam fir in winter to save energy because the twigs weigh 8 to 13 times more than deciduous twigs of similar length and therefore it requires less time and effort to consume equivalent amounts [41]. Balsam fir is unimportant in the diets of caribou and white-tailed deer. Spruce and ruffed grouse feed on balsam fir needles, tips, and buds, which often make up 5 to 10 percent of the fall and winter diet. Red squirrels feed on balsam fir male flower buds, and less frequently on leader and lateral buds in late winter and spring when other foods are scarce [5]. Stands attacked by the spruce budworm attract numerous insect-eating birds, especially warblers and woodpeckers [30]. PALATABILITY : Balsam fir is moderately to highly palatable to moose in winter. Palatability varies between individual plants. Green-foliaged individuals are often browsed heavily, while chlorotic plants are avoided [5]. This is attributed to the higher nutrient content of healthy plants with dark green foliage. The palatability of balsam fir to white-tailed deer and caribou is low [5]. White-tailed deer may eat small amounts of balsam fir due to its abundance, but it is not a preferred food [51]. In laboratory experiments, mice and voles preferred the seeds of pines (Pinus spp.), spruces (Picea spp.), and eastern hemlock over balsam fir seeds [5]. NUTRITIONAL VALUE : In Newfoundland, healthy balsam fir plants with dark blue-green foliage are more nutritious than plants with yellow or light green foliage. Chemical analysis of balsam fir browse during the growing season varied according to color as follows [8]: (percent composition on dry matter basis) foliage color protein fat fiber ash N-free Mg K Extract very yellow 4.65 7.54 25.2 2.1 60.60 0.12 0.32 yellow 5.49 8.29 22.01 2.49 61.72 0.18 0.15 light green 6.33 7.71 22.83 2.44 60.69 0.13 0.27 green 6.89 8.08 21.36 3.24 60.43 0.13 0.42 dark green 8.59 7.88 20.67 3.54 59.41 0.09 0.44 dark blue-green 13.54 5.55 26.24 3.68 50.99 0.13 1.01 On logged-over land in Newfoundland, twigs from balsam fir saplings in thinned stands contained 33 percent more protein and 17 percent more crude fat than those from unthinned stands [53]. COVER VALUE : Balsam fir provides important winter cover for white-tailed deer and moose. Balsam fir stands attract ungulates because snow is not as deep as in adjacent hardwood stands [30]. Lowland balsam fir stands are used extensively by white-tailed deer as winter yarding areas [21], and by moose with calves during severe winters [30]. During summer, deer, bear, and moose often rest under the shade of balsam fir trees [30]. Young balsam firs provide cover for small mammals and birds. Martens, hares, songbirds, and even deer hide from predators in balsam fir thickets [30]. Grouse and songbirds seek shelter during winter within the evergreen foliage [5]. In Maine, fishers often nest in witches brooms in balsam fir trees [4]. VALUE FOR REHABILITATION OF DISTURBED SITES : The use of balsam fir for rehabilitation purposes is largely unexplored. It is probably best suited for long-term revegetation. Nursery-grown stock is available for outplanting. Methods for collecting, processing, testing, storing, and sowing balsam fir seed, as well as nursery practices for seedling production, have been outlined in the literature [5,16,24]. OTHER USES AND VALUES : Balsam fir is a popular Christmas tree in the East and grown on plantations for this purpose. The branches are used to make Christmas wreaths. The fragrant needles are used as a stuffing in souvenir pillows sold in New England [21]. Balsam fir is occasionally used in landscaping. It can be used in screenings, mass plantings, and windbreaks but requires abundant soil moisture for these purposes [21]. Bark blisters contain oleoresin, which is used in the optics industry as a medium for mounting microscope specimens and as a cement for various parts of optical systems [21]. OTHER MANAGEMENT CONSIDERATIONS : Silviculture: Balsam fir is managed under both even- and uneven-aged silvicultural systems [22,23,30]. Balsam fir types are usually converted to other forest types because of their susceptibility to spruce budworm outbreaks and because of the relatively low value of the timber [30]. Wildlife damage: White-tailed deer, snowshoe hares, and especially moose browse balsam fir reproduction on cutovers. This often retards growth but is seldom fatal [30]. In Newfoundland, 4-foot-tall (1.2 m) balsam fir survived up to 12 years of heavy moose browsing [8]. Release: Several herbicides are used to release balsam fir from competing hardwoods. Balsam fir is resistant to 2,4-D, 2,4,5-T, glyphosate, and hexazinone [30,40]. Insects: The spruce budworm is the most serious damaging agent of balsam fir. Historically, cyclical spruce budworm epidemics have killed trees over vast areas [55]. The most susceptible stands are those with the following characteristics [30]: (1) High basal area or percentage of stand in balsam fir and/or white spruce; (2) Mature stands (50 years or older), especially if extensive; (3) Open stands with tops of balsam fir and/or white spruce protruding above the canopy; (4) Stands on poorly drained soils that are extremely wet or dry; and (5) Stands downwind of a budworm outbreak area. Once an outbreak begins, trees usually die after 3 to 5 years of continuous defoliation. Johnston [30] has outlined management principles for spruce-budworm-infested balsam fir. Other serious insect pests include the hemlock looper and blackheaded budworm, defoliators primarily associated with mature and overmature stands [30]. The introduced balsam wooly adelgid, which occurs in southeastern Canada and the northeastern United States, attacks stems, twigs, and buds and can kill trees within 3 years [21]. Rots: Several heart, butt, and root rots cause much decay in living trees. Heart rots often infect more than 50 percent of 70-year-old trees [6].


SPECIES: Abies balsamea
GENERAL BOTANICAL CHARACTERISTICS : Balsam fir is a native, coniferous, evergreen, small to medium-sized, upright tree. At maturity it may reach a height of 40 to 90 feet (12-27 m) and a d.b.h. of 12 to 30 inches (30-75 cm) [5]. Maximum age is about 200 years. Balsam fir has a dense, narrowly pyrimidal crown terminating in a slender, spirelike top. Open-grown trees may have live branches extending to the ground, but trees in well-stocked stands have dead, persistent lower branches [29]. The needles are flat, resinous, and 0.4 to 1.2 inches (1-3 cm) long [5]. Erect cones occur on the upper side of 1-year-old branches in the upper crown. The bark is gray and smooth and contains numerous raised resin blisters. On older trees the bark becomes brown and scaly but is less than 0.5 inch (1.2 cm) thick [5]. Balsam fir has a shallow root system that is mostly confined to duff and upper mineral soil layers. Roots rarely penetrate more than 30 inches (75 cm) below the ground surface, except in sandy soils [21]. RAUNKIAER LIFE FORM : Phanerophyte REGENERATION PROCESSES : Seed production and dispersal: Balsam fir is a prolific seed producer. Seed production begins when plants are about 20 years old or 15 feet tall [5], and regular seed production occurs after trees are about 30 years old. Some seed is produced every year, with heavy seed crops occurring at 2- to 4-year intervals [21]. Most seeds are shed in autumn, but small amounts fall throughout the winter and into spring [21]. The winged seeds are primarily dispersed by wind. Most fall within 80 to 200 feet (25-60 m) of the tree, but some travel up to 525 feet from the tree (160 m) [21]. Some seed is dispersed by small mammals. Only about 50 percent of balsam fir seeds are sound [24]. Germinative capacity is relatively low, ranging from about 20 to 50 percent [5]. Seeds remain viable for less than 1 year under natural conditions [21]. Germination and seedling establishment: Most seeds germinate between late May and early July [21]. If moisture is sufficient, seedlings will establish on almost any substrate, but establishment is generally best on mineral soil. Other good seedbeds include rotting wood embedded in humus because it can remain moist even during prolonged drought, and rotting logs and stumps because they have a tendency to shed hardwood leaf litter which can smother seedlings [36]. Hardwood leaf litter is a poor seedbed; seedlings on deep layers of hardwood litter usually die within a few weeks of germination [5]. However, balsam fir establishes more readily on shallow litter (less than 3 inches [7.5 cm]) than other conifers because seedlings quickly develop a deep root system [21]. Seedlings are very shade tolerant. Once established they can withstand many years of suppression. Vegetative reproduction: Layering occurs in swamps and mossy areas, and under white and jack pine (Pinus strobus, P. banksiana) overstories [5]. In the White Mountains of New Hampshire, prostrate balsam fir above 5,500 feet (1,700 m) in elevation reproduce almost entirely by layering [5]. SITE CHARACTERISTICS : Balsam fir grows on a wide variety of upland and lowland sites. It occurs on mountain slopes and glaciated uplands as well as on alluvial flats, peatlands, and swamps. It is found in pure, mixed coniferous, and mixed coniferous-deciduous stands. Soils: Balsam fir grows on sites underlain by a variety of parent materials, including gneiss, schist, anorthosite, diabase, slate, sandstone, and limestone. It grows mostly on acid Spodosol, Inceptisol, and Histisol soil orders [21]. It grows on all soil textures, from heavy clay to rocky. It tolerates a wide range of soil acidity. In the Lake States, balsam fir is most common on cool, wet-mesic sites with soil pH values between 5.1 and 6.0 [21]. In northeast Wisconsin it commonly grows on limestone outcrops [45]. Associated trees: Associated trees of uplands include white spruce, red spruce, paper birch, aspen, white ash (Fraxinus americana), yellow birch (Betula alleghaniensis), American beech (Fagus grandifolia), red maple, sugar maple (Acer saccharum), eastern hemlock, and white pine. Lowland associates are black spruce, white spruce, tamarack (Larix laricina), red maple, black ash (Fraxinus nigra), and northern white-cedar [17]. Understory: Common shrub associates include beaked hazel (Corylus cornuta), bog Labrador-tea (Ledum groenlandicum), mountain maple (Acer spicatum), Canada yew (Taxus canadensis), red raspberry (Rubus idaeus), sheep laurel (Kalmia angustifolia), and hobblebush (Viburnum lantanoides) [21]. Elevation: Balsam fir grows from near sea level along the Atlantic seaboard to timberline at 5,600 feet (1,700 m) in the Appalachian Mountains, and to 6,200 feet (1,890 m) in the White Mountains in New Hampshire [21]. SUCCESSIONAL STATUS : Balsam fir is a late successional or climax species. Following fire, it is replaced by pioneering hardwoods and conifers, such as aspen, paper birch, balsam poplar (Populus balsamifera), jack pine, and black spruce. Except for scattered survivors, it is mostly absent for the first few postfire decades. In Ontario, balsam fir seedlings often first appear under aspen-birch-spruce types 30 to 50 years after fire [5,36]. Balsam fir seedlings are shade tolerant and less exacting in seedbed requirements than many associates. It readily establishes under a canopy of hardwoods and conifers. In the Lake States, an understory of balsam fir seedlings is almost ubiquitous in several upland and lowland forests [30]. In boreal forests, it is usually a common understory component beneath pines, aspen, and paper birch [7,15,28]. In the continued absence of fire, balsam fir may assume dominance as the canopy of the pioneering trees begins to break up. In the Lake States, balsam fir can become climax on poorly drained clay soils. It often succeeds aspen, paper birch, and sometimes black spruce [17]. On mesic sites, it is often replaced by shade-tolerant hardwoods such as sugar maple [30]. SEASONAL DEVELOPMENT : Phenological events proceed as follows [5]: Event Southern part of range Northern part of range flowering begins early May early June seeds ripen late August-early Sept. October seedfall begins early September October


SPECIES: Abies balsamea
FIRE ECOLOGY OR ADAPTATIONS : Balsam fir is easily killed by fire. Seedlings establish after fire only if surviving seed trees are present. Balsam fir is therefore a rare postfire pioneer [14]. 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


SPECIES: Abies balsamea
IMMEDIATE FIRE EFFECT ON PLANT : Balsam fir is the least fire-resistant conifer in the northeastern United States [48]. Most fires kill balsam fir trees and destroy the seeds [14]. Trees have thin, resinous, easily ignitable bark and shallow roots [1,21]. Seeds have no endosperm to protect them from high temperatures. Cones are not necessarily destroyed by fire, but immature seeds will not ripen on fire-killed trees. If balsam fir trees are killed over extensive areas by summer fires, no seed will be available to revegetate the burned area. This occurred following the 1936 wildfire on Isle Royale which burned 26,000 acres (10,500 ha). Most of the balsam fir trees were killed, and for 30 years after the fire, balsam fir was largely absent from the burned area [27]. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : Balsam fir is generally slow to reestablish after fire. Because most trees are killed by fire, it relies on rare survivors found in protected pockets within the burn or trees from adjacent unburned areas to provide seed for postfire seedling establishment. Associates such as aspen, paper birch, black spruce, and jack pine usually seed in aggressively following fire and quickly dominate the site. Balsam fir is usually rare or absent for the first 30 to 50 years after fire, but thereafter gradually establishes under the canopy of its seral associates [2,14,20]. DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : Fire creates seedbeds favorable for balsam fir germination and establishment. If seed is available, balsam fir readily establishes on burned sites. In northern Minnesota, balsam fir seedlings were established within 5 years of a stand-destroying fire; seed originated from an unburned mixed-conifer stand across a river [28]. Balsam fir seedlings establish after fall fires that occur when seed is ripe and still on the tree [11]. FIRE MANAGEMENT CONSIDERATIONS : Prescribed fire: Prescribed fire can be used to convert balsam fir forests to other species. It is an important silvicultural tool in spruce budworm-infested stands. Burning infested stands eliminates the unaffected balsam fir understory and prepares the site for other commercial species, particularly black spruce [25]. In northern Ontario, prescribed burning on sites pretreated by tramping (leveling the dead trees with bulldozers) successfully prepared a spruce budworm-killed balsam fir stand for planting [38]. Tramping aided fire spread in this summer burn, when green herbaceous plants might otherwise have hindered it. The standing dead trees were dry before tramping. Some large balsam fir boles were completely consumed and 55 percent of balsam fir slash between 2.75 and 5 inches (7-13 cm) in diameter were consumed. Prescribed fires can also be used to kill balsam fir seedlings and saplings in pine and mixed-wood types. In these types, low-intensity surface fires are sufficient to kill balsam fir saplings [37]. Fire behavior: Balsam fir tree mortality is often between 70 and 100 percent after the collapse of a spruce budworm outbreak [25]. These altered forests are more flammable because the dead trees provide dry aerial fuel and the newly exposed understory is drier than normal. Fire suppression in spruce budworm-killed stands is extremely difficult [25]. Experimental burns in spruce budworm-killed stands have been explosive. In balsam fir stands with 30- to 90-year-old dead trees averaging 23 to 39 feet (7-12 m) in height, spring fires (before flushing of understory vegetation), under conditions of high but not extreme fire danger, burned with intensities as high as 38,000 KW/m and spread rates in excess of 148 feet/minute (45 m/min.) [50]. Tree crown and surface fuel consumption were nearly complete, and standing tree boles smoldered for hours after the passage of the fire front. These hot fires transport large amounts of peeling bark, fine twigs, and branchlets in convection columns which start spot fires downwind [49]. Decay after fire: Fire-killed balsam fir deteriorates rather slowly. Commercial salvage operations are possible for a number of years after stand-killing fires [5]. However, budworm-killed trees quickly succumb to wood-rotting fungi and are largely unusable after 1 to 3 years [34].


SPECIES: Abies balsamea
REFERENCES : 1. A. D. Revill Associates. 1978. Ecological eff. of fire and its mgmt. in Canada's national parks: a synthesis of the literature. Vols 1&2. Lit. Rev. & Annot. Bibliography. Ottawa, ON: Parks Canada, National Parks Branch, Natural Resources Division. 345 p. [3416] 2. Apfelbaum, Steven; Haney, Alan. 1981. Bird populations before and after wildfire in a Great Lakes pine forest. Condor. 83: 347-354. [8556] 3. Armson, K. A. 1988. The boreal mixedwood forests of Ontario: past, present, and future. In: Samoil, J. K., ed. Management and utilization of northern mixedwoods: Proceedings of a symposium; 1988 April 11-14; Edmonton, AB. Inf. Rep. NOR-X-296. Edmonton, AB: Canadian Forestry Service, Northern Forestrty Centre: 13-17. [13041] 4. Arthur, Stephen M.; Krohn, William B.; Gilbert, James R. 1989. Habitat use and diet of fishers. Journal of Wildlife Management. 53(3): 680-688. [8671] 5. Bakuzis, E. V.; Hansen, H. L.; with contrib. by Kaufert, F. H.; Lawrence, D. B.; Duncan, D. P.; [and others]. 1965. Balsam fir, Abies balsamea (Linnaeus) Miller; a monographic review. Minneapolis, MN: The University of Minnesota Press. 445 p. [8432] 6. Frank, Robert M. 1990. Abies balsamea (L.) Mill. balsam fir. In: Burns, Russell M.; Honkala, Barbara H., technical coordinators. Silvics of North America. Volume 1. Conifers. Agric. Handb. 654. Washington, DC: U.S. Department of Agriculture, Forest Service: 26-35. [13365] 7. Bergeron, Yves; Dubuc, Michelle. 1989. Succession in the southern part of the Canadian boreal forest. Vegetatio. 79: 51-63. [5042] 8. Bergerud, Arthur T.; Manuel, Frank. 1968. Moose damage to balsam fir-white birch forests in central Newfoundland. Journal of Wildlife Management. 32(4): 729-746. [14203] 9. 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] 10. Crete, Michel; Jordan, Peter A. 1982. Production and quality of forage available to moose in southwestern Quebec. Canadian Journal of Forest Research. 12: 151-159. [8229] 11. Damman, A. W. H. 1964. Some forest types of central Newfoundland and their relation to environmental factors. Forest Science Monograph 8. Washington, DC: Society of American Foresters. 62 p. [14281] 12. Dansereau, Pierre. 1959. The principal plant associations of the Saint Lawrence Valley. No. 75. Montreal, Canada: Contrib. Inst. Bot. Univ. Montreal. 147 p. [8925] 13. Day, R. J.; Bell, F. W. 1988. Development of crop plans for hardwood and conifer stands on boreal mixedwood sites. In: Samoil, J. K., ed. Management and utilization of northern mixedwoods: Proceedings of a symposium; 1988 April 11-14; Edmonton, AB. Inf. Rep. NOR-X-296. Edmonton, AB: Canadian Forestry Service, Northern Forestrty Centre: 87-98. [13050] 14. Day, R. J.; Harvey, E. M. 1981. Forest dynamics in boreal mixedwood. In: Whitney, R. D.; McClain, K. M., compilers. Boreal mixedwood: Proceedings of a symposium; [Date of conference unknown]; [Location of conference unknown]. COJFRC Symp. Proc. O-P-9. Sault Ste. Marie, ON: Environment Canada, Canadian Forestry Service, Great Lakes Forestry Research Centre: 29-41. [14204] 15. Dix, R. L.; Swan, J. M. A. 1971. The roles of disturbance and succession in upland forest at Candle Lake, Saskatchewan. Canadian Journal of Botany. 49: 657-676. [12808] 16. Edwards, D. G. W. 1982. Collection, processing, testing, and storage of true fir seeds--a review. 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; Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station: 113-137. [11894] 17. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905] 18. Foster, David R. 1983. The history and pattern of fire in the boreal forest of southeastern Labrador. Canadian Journal of Botany. 61: 2459-2471. [9683] 19. Foster, David R. 1985. Vegetation development following fire in Picea mariana (black spruce) - Pleurozium forests of south-eastern Labrador, Canada. Journal of Ecology. 73: 517-534. [7222] 20. Foster, D. R.; King, G. A. 1986. Vegetation pattern and diversity in southeastern Labrador, Canada: Betula papyrifera (birch) forest development in relation to fire history and physiography. Journal of Ecology. 74: 465-483. [14651] 21. Frank, Robert M. 1990. Abies balsamea (L.) Mill. balsam fir. In: Burns, Russell M.; Honkala, Barbara H., technical coordinators. Silvics of North America. Volume 1. Conifers. Agric. Handb. 654. Washington, DC: U.S. Department of Agriculture, Forest Service: 26-35. [13365] 22. Frank, Robert M.; Bjorkbom, John C. 1973. A silvicultural guide for spruce-fir in the northeast. NE-6. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 29 p. [8686] 23. Frank, Robert M.; Blum, Barton M. 1978. The selection system of silviculture in spruce-fir stands--procedures, early results, and comparisons with unmanaged stands. Res. Pap. NE-425. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 15 p. [8772] 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. Furyaev, V. V.; Wein, Ross W.; MacLean, David A. 1983. Fire influences in Abies-dominated forests. In: Wein, Ross W.; MacLean, David A., eds. The role of fire in northern circumpolar ecosystems. Scope 18. Chichester; New York: John Wiley & Sons: 221-234. [14610] 26. 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] 27. Hansen, H. L.; Krefting, L. W.; Kurmis, V. 1973. The forest of Isle Royale in relation to fire history and wildlife. Tech. Bull. 294; Forestry Series 13. Minneapolis, MN: University of Minnesota, Agricultural Experiment Station. 44 p. [8120] 28. Heinselman, Miron L. 1973. Fire in the virgin forests of the Boundary Waters Canoe Area, Minnesota. Quaternary Research. 3: 329-382. [282] 29. Hosie, R. C. 1969. Native trees of Canada. 7th ed. Ottawa, ON: Canadian Forestry Service, Department of Fisheries and Forestry. 380 p. [3375] 30. Johnston, William F. 1986. Manager's handbook for balsam fir in the North Central States. Gen. Tech. Rep. NC-111. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station. 27 p. [9219] 31. 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] 32. Little, Elbert L., Jr. 1979. Checklist of United States trees (native and naturalized). Agric. Handb. 541. Washington, DC: U.S. Department of Agriculture, Forest Service. 375 p. [2952] 33. 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] 34. MacLean, David A. 1980. Vulnerability of fir-spruce stands during uncontrolled spruce budworm outbreaks: a review and discussion. Forestry Chronicle. 56: 213-221. [14609] 35. MacLean, D. W. 1949. Forest development on the Goulais River watershed, 1910-1946. Silvicultural Res. Note No. 94. Ottawa, Canada: Department of Mines and Resources, Mines, Forests and Scientific Services Branch, Dominion Forest Service. 54 p. [14607] 36. MacLean, D. W. 1960. Some aspects of the aspen-birch-spruce-fir type in Ontario. Tech. Note No. 94. Ottawa, Canada: Department of Forestry, Forest Research Division. 24 p. [14608] 37. Methven, Ian R.; Murray, W. G. 1974. Using fire to eliminate understory balsam fir in pine management. Forestry Chronicle. 50(2): 77-79. [7631] 38. McRae, D. J. 1986. Prescribed burning for stand conversion in budworm-killed balsam fir: an Ontario case history. Forestry Chronicle. 62(2): 96-100. [12379] 39. Ohmann, Lewis F.; Ream, Robert R. 1971. Wilderness ecology: virgin plant communities of the Boundary Waters Canoe Area. Res. Pap. NC-63. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station. 55 p. [9271] 40. Parker, Robert, compiler. 1982. Reaction of various plants to 2,4-D, MCPA, 2,4,5-T, silvex and 2,4-DB. Pullman, WA: Washington State University, College of Agriculture, Cooperative Extension. 61 p. In cooperation with: U.S. Department of Agriculture. [1817] 41. Peek, J. M. 1974. A review of moose food habits studies in North America. Le Naturaliste Canadien. 101: 195-215. [7420] 42. Place, I. C. M. 1955. The influence of seed-bed conditions on the regeneration of spruce and balsam fir. Bulletin 117. Ottawa, Canada: Department of Northern Affairs and National Resources, Forestry Branch, Forest Research Division. 87 p. [14274] 43. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843] 44. Rowe, J. S.; Scotter, G. W. 1973. Fire in the boreal forest. Quaternary Research. 3: 444-464. [72] 45. Rudolf, Paul O. 1966. Botanical and commercial range of balsam fir in the Lake States. Res. Note NC-16. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station. 4 p. [9196] 46. Samoil, J. K., ed. 1988. Management and utilization of northern mixedwoods: Proceedings of a symposium; 1988 April 11-14; Edmonton, AB. Inf. Rep. NOR-X-296. Edmonton, AB: Canadian Forestry Service, Northern ForestryCentre. 163 p. [13039] 47. Seymour, Frank Conkling. 1982. The flora of New England. 2d ed. Phytologia Memoirs 5. Plainfield, NJ: Harold N. Moldenke and Alma L. Moldenke. 611 p. [7604] 48. Starker, T. J. 1932. Fire resistance of trees of northeast United States. Forest Worker. 8(3): 8-9. [81] 49. Stocks, B. J. 1987. Fire potential in the spruce budworm-damaged forests of Ontario. Forestry Chronicle. 63(1): 8-14. [12369] 50. Stocks, Brian J.; Alexander, Martin E. 1980. Forest fire behaviour and effects research in northern Ontario: a field oriented program. In: Martin, Robert E.; Edmonds, Robert L.; Faulkner, Donald A.; [and others], eds. Proceedings, 6th conference on fire and forest meteorology; 1980 April 22-24; Seattle, WA. Washington, DC: Society of American Foresters: 18-24. [10291] 51. Telfer, Edmund S. 1972. Browse selection by deer and hares. Journal of Wildlife Management. 36(4): 1344-1349. [12455] 52. Thomas, P. A.; Wein, Ross W. 1985. The influence of shelter and the hypothetical effect of fire severity on the postfire establishment of conifers from seed. Canadian Journal of Forest Research. 15: 148-155. [7291] 53. Thompson, Ian D.; Curran, William J. 1989. Moose damage to pre-commercially thinned balsam fir stands: review of research and management implications. Inf. Rep. N-X-272. St. John's, NF: Forestry Canada, Newfoundland and Labrador Region. 17 p. [13648] 54. 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] 55. Weetman, G. F. 1983. Management of balsam fir in eastern North America. 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: 221-225. [14523] 56. Zoladeski, C. A. 1988. Classification and gradient analysis of forest vegetation of Cape Enrage, Bic Park, Quebec. Le Naturaliste Canadien. 115(1): 9-18. [13610] 57. Jones, R. Keith; Pierpoint, Geoffrey; Wickware, Gregory M.; [and others]. 1983. Field guide to forest ecosystem classification for the Clay Belt, site region 3e. Maple, Ontario: Ministry of Natural Resources, Ontario Forest Research Institute. 160 p. [16163]