dcsimg
542.3204604531.130x130
Life » » Plants »

Abies lasiocarpa (Hook.) Nutt.

Distribution

    Distribution
    provided by Fire Effects Information System Plants
    Subalpine fir is the mostly widely distributed fir in North America,
    spanning more than 32 degrees of latitude [11].  It occurs chiefly in
    mountainous areas from the Yukon interior near treeline and along the
    coast of southeastern Alaska south through western Alberta and British
    Columbia to southern Colorado and scattered mountain ranges of Arizona
    and New Mexico [54,75].  In the western portion of its range, subalpine
    fir does not occur along the western slope of the Coast Range in
    southern British Columbia or along the Coast Ranges of Washington and
    Oregon but does occur on Vancouver Island and in the Olympic Mountains
    of Washington [11].  It occurs on both slopes of the Cascade Mountains
    as far south as southern Oregon [11].  The two varieties are distributed
    as follows [11,75]:

    A. l. var. lasiocarpa (typical variety) - almost the same as the species,
    but not in central and southeastern Arizona. 

    A. l. var. arizonica - from central Colorado to southwestern New Mexico, and
    in southeastern and central Arizona. 

    Subalpine fir and corkbark fir occur together in scattered mountain
    ranges in southwestern Colorado, northern, western, and southwestern New
    Mexico, and in the high mountains of Arizona [11].


     
    Distributions of corkbark fir (A) and the typical variety (B). Maps courtesy of USDA, NRCS. 2018. The PLANTS Database.
    National Plant Data Team, Greensboro, NC [117] [2018, March 22].

    Occurrence in North America
    provided by Fire Effects Information System Plants
         AK  AZ  CO  ID  MT  NV  NM  OR  UT  WA
         WY  AB  BC  YT
    Regional Distribution in the Western United States
    provided by Fire Effects Information System Plants
    More info on this topic.

    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):

        1  Northern Pacific Border
        2  Cascade Mountains
        5  Columbia Plateau
        6  Upper Basin and Range
        8  Northern Rocky Mountains
        9  Middle Rocky Mountains
       11  Southern Rocky Mountains
       12  Colorado Plateau

Morphology

    Description
    provided by Fire Effects Information System Plants
    More info for the terms: monoecious, tree

    Subalpine fir is a native, coniferous, evergreen tree.  It is the
    smallest of the eight species of fir native to the western United
    States.  Five growth forms, each apparently an adaptation to a
    particular environment, are described below [9,54]:

    1.  The typical form is found throughout much of the subalpine zone.
    These trees have an extremely narrow and dense crown with short
    branches.  Trees growing in openings retain their lower branches, which
    often droop and extend down to the ground.  Trees growing in the
    overstory may be clear of lower branches for 20 to 30 percent of the
    tree's height.

    2.  A somewhat broad-crowned, bullet-shaped tree is more typical of
    older specimens and drier climates. 

    3.  A mature tree with a layered apron is occasionally found in some
    areas.

    4.  A flag form tree often occurs at timberline.  These individuals are
    characterized by an upright trunk that extends above a krummholzlike
    mat.  Branches on the trunk generally grow only along the leeward side
    of the trunk, giving the plant a flaglike appearance.

    5.  The krummholz form is typical of alpine areas above timberline.  In
    these areas, because of cold temperatures and severe winds, subalpine
    fir grows in dwarfed, shrubby mats along the ground, and is often much
    broader than it is tall.

    The typical form often grows to heights of 60 to 100 feet (18-30 m), and
    trunk diameters reach 18 to 24 inches (46-61 cm) [39].  Trees up to 130
    feet (40 m) tall and 30 inches (76 cm) in diameter have been found but
    are rare [39].  Subalpine fir grows very slowly; 150- to 200-year-old
    trees are usually only 10 to 20 inches (25-50 cm) in diameter [39].
    Trees seldom live more than 250 years because they are very susceptible
    to heart rots [9].

    Needles are blunt tipped, flattened, and 1 to 1.2 inches (2.5-3 cm) long
    [25,57].  Bark on young trees is thin, gray, and smooth, with numerous
    resin vesicles; on older trees it is shallowly fissured and scaly [9].
    Corkbark fir is generally recognized by its creamy-white, thick, corky
    bark [25].  The root system generally is shallow but under favorable
    conditions may develop relatively deep laterals [9].

    Subalpine fir is monoecious.  Single or small bunches of erect female
    cones occur in the upper part of the crown on the upper side of young
    branches.  Dense clusters of the smaller male cones occur lower on the
    crown on the underside of 1-year-old twigs.  Subalpine fir seeds are
    0.23 to 0.28 inch (6-7 mm) long and have broad wings about 0.4 inch (1
    cm) long [25,121].  Corkbark fir seeds are about 70 percent larger than
    subalpine fir seeds [39].

Habitat

    Habitat characteristics
    provided by Fire Effects Information System Plants
    More info for the terms: association, climax, habitat type, tundra

    Subalpine fir is a middle to upper elevation mountain conifer.  It
    generally occupies sites with a short growing season caused by cold
    winters, cool summers, frequent summer frosts, and heavy snowpack.  It
    forms extensive forests between warm and dry lower elevation forests of
    Douglas-fir, white fir (Abies concolor), grand fir, lodgepole pine, or
    blue spruce (Picea pungens) and higher elevation alpine tundra
    [23,29,112,125].  At its lower elevational limits, subalpine fir is
    often restricted to streambottoms, ravines, frosty basins, or north
    exposures.  It increasingly occupies westerly and easterly aspects with
    increasing elevation and may occupy all aspects at upper timberline
    [23,91].

    Stand condition and associated conifers:  Throughout its range,
    subalpine fir is most commonly associated with Engelmann spruce.  These
    two species frequently occur as codominants forming widespread subalpine
    forests.  In the central and southern Rocky Mountains, Engelmann spruce
    commonly makes up 70 percent of overstory trees, with subalpine fir
    dominating the understory [9].  Within spruce-fir forests of this
    region, Engelmann spruce tends to be more important at higher elevations
    and on wetter sites, while subalpine fir is more abundant on drier lower
    elevation sites [9].  In the northern Rocky Mountains, subalpine fir
    typically dominates climax stands, but Engelmann spruce becomes
    increasingly important on moist, cool sites [23,91].  Other associates
    which vary by latitude and elevation are listed below [39]:

    Location              Elevation   Associates

    northern Rocky Mtns   low         western white pine (Pinus monticola),
                                      Douglas-fir, western larch (Larix
                                      occidentalis), grand fir, western hemlock
                                      (Tsuga heterophylla), western redcedar
                                      (Thuja plicata)
                           high       lodgepole pine, subalpine larch (Larix
                                      lyallii), whitebark pine (Pinus
                                      albicaulis), mountain hemlock
    central Rocky Mtns     low        lodgepole pine, Douglas-fir, aspen
                                      (Populus tremuloides), blue spruce
                           high       whitebark pine, limber pine (Pinus
                                      flexilis), bristlecone pine (P. aristata)
    southern Rocky Mtns    low        white fir, Douglas-fir, blue spruce, aspen
                           high       corkbark fir
    Cascade Mtns           low        Pacific silver fir, mountain hemlock,
                                      lodgepole pine 
                           high       mountain hemlock, whitebark pine

    Understory associates:  Understory vegetation is extremely variable,
    changing with elevation, exposure, and soil moisture.  Habitat type and
    plant association guides describe characteristic understory plants for
    differing sites.

    Elevation:  Alexander and others [11] described the following
    elevational ranges for subalpine fir:

    Coast Range of southeastern Alaska - subalpine fir is found from sea
    level to 3,500 feet (0-1,067 m). 

    Coast Range and interior plateaus of Yukon Territory and British
    Columbia - subalpine fir is found from 2,000 to 5,000 feet (610-1,524
    m).

    Olympic and Cascade Mountains of Washington and Oregon - subalpine fir
    is generally found from 4,000 to 6,000 feet (1,219-1,829 m), but may be
    found as low as 2,000 feet (610 m) along cold streambottoms and on lava
    flows, and as high as 8,000 feet (2,438 m) on sheltered slopes.

    Rocky Mountains of British Columbia and Alberta south of the Peace River
    - subalpine fir is found from 3,000 to 7,000 feet (914-2,134 m) but is
    more abundant above 5,000 feet (1,524 m).

    Rocky Mountains of Montana and Idaho and associated ranges of eastern
    Oregon and Washington - subalpine fir grows from 2,000 to 11,000 feet
    (610-3,353 m) but is most common at 5,000 to 9,000 feet (1,524-2,743 m).

    Rocky Mountains of Wyoming, Utah, and Colorado - subalpine fir occurs
    from 8,000 to 11,500 feet (2,438-3,506 m) but is most common at 9,000 to
    11,000 feet (2,743-3,353 m).

    Rocky Mountains of New Mexico and Arizona - subalpine fir occurs from
    8,000 to 12,000 feet (2,438-3,658 m) but is usually found on north
    slopes from 9,500 to 11,000 feet (2,896-3,353 m).
    Habitat: Cover Types
    provided by Fire Effects Information System Plants
    More info on this topic.

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

       201  White spruce
       202  White spruce - paper birch
       205  Mountain hemlock
       206  Engelmann spruce - subalpine fir
       208  Whitebark pine
       209  Bristlecone pine
       210  Interior Douglas-fir
       212  Western larch
       213  Grand fir
       215  Western white pine
       216  Blue spruce
       217  Aspen
       218  Lodgepole pine
       219  Limber pine
       223  Sitka spruce
       224  Western hemlock
       226  Coastal true fir - hemlock
       253  Black spruce - white spruce
    Habitat: Ecosystem
    provided by Fire Effects Information System Plants
    More info on this topic.

    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):

       FRES20  Douglas-fir
       FRES22  Western white pine
       FRES23  Fir - spruce
       FRES24  Hemlock - Sitka spruce
       FRES25  Larch
       FRES26  Lodgepole pine
       FRES44  Alpine
    Habitat: Plant Associations
    provided by Fire Effects Information System Plants
    More info on this topic.

    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

       K004  Fir - hemlock forest
       K012  Douglas-fir forest
       K015  Western spruce - pine forest
       K018  Pine - Douglas-fir forest
       K020  Spruce - fir - Douglas-fir forest
       K021  Southwestern spruce - fir forest
       K052  Alpine meadows and barren
    Key Plant Community Associations
    provided by Fire Effects Information System Plants
    More info for the terms: climax, codominant, forest, grassland, series, shrubland, woodland

    Forests in which subalpine fir attains climax dominance or codominance
    are widespread throughout the mountains of western North America.  The
    subalpine fir series generally occupies cold, high elevation mountain
    forests.  Engelmann spruce (Picea engelmannii) is usually associated
    with subalpine fir.  It occurs as either a climax codominant or as a
    persistent, long-lived seral species in most subalpine fir habitat
    types.

    Published classification schemes listing subalpine fir as a dominant
    part of the vegetation in habitat types (hts), community types (cts),
    plant associations (pas), ecosystem associations (eas), site types (sts)
    or dominance types (dts) are presented below:

    Area                    Classification          Authority

    AK: -----               general veg. cts        Viereck & Dyrness 1980
    AZ: San Francisco       forest, alpine &
          Peaks RNA           meadow cts            Rominger & Paulik 1983
    AZ, NM: -----           forest & woodland hts   Layser & Schubert 1979
            Apache, Gila,
              Cibola NFs    forest hts              Fitzhugh & others 1987
            s of Mogollon
              Rim           forest hts              Develice & Ludwig 1983b
    n AZ, n NM              forest hts              Larson & Moir 1987
    CO: Arapaho &
          Roosevelt NFs     forest hts              Hess & Alexander 1986
        Gunnison &
          Uncompahgre NFs   forest hts              Komarkova & others 1988
        Routt NF            forest hts              Hoffman & Alexander 1980
        White River-        grassland, shrubland,
          Arapaho NF          & forestland hts      Hess & Wasser 1982
        White River NF      forest hts              Hoffman & Alexander 1983
    w CO                    riparian pas            Baker 1989a
    ID: Sawtooth, White
          Cloud, Boulder,
          & Pioneer Mtns    general veg. cts        Schlatterer 1972
    c ID                    forest hts              Steele & others 1981
    n ID                    forest hts              Cooper & others 1987
    se ID                   aspen cts               Mueggler & Campbell 1986
    e ID, w WY              forest hts              Steele & others 1983
    MT: -----               forest hts              Pfister & others 1977
        -----               riparian dts            Hansen & others 1988
    c, e MT                 riparian cts, hts       Hansen & others 1990
    nw MT                   riparian hts, cts       Boggs & others 1990
    sw MT                   riparian rst, cts, hts  Hansen & others 1989
    NM: Cibola NF           forest hts              Alexander & others 1987
        Lincoln NF          forest hts              Alexander & others 1984
    n NM, s CO              forest hts              Develice & Ludwig 1983a
    n NM, s CO              forest hts              Develice  & others 1986
    OR: Wallowa-Whitman NF  steppe & forest pas     Johnson & Simon 1987
        Eagle Cap
          Wilderness        general veg. cts        Cole 1982
    OR, WA: -----           general veg. cts        Franklin & Dyrness 1973
            Blue Mtns       general veg. pas        Hall 1973
    UT: -----               aspen cts               Mueggler & Campbell 1986
    c, s UT                 forest hts              Youngblood & Mauk 1985
    n UT                    forest hts              Mauk & Henderson 1984
    WA: Okanogan NF         forest pas              Williams & Lillybridge 1983
        Mount Rainier NP    forest pas              Franklin & others 1988   
        North Cascades NP   forest pas              Agee & Kertis 1987
    e WA, n ID              forest hts, cts         Daubenmire & Daubenmire 1968
    WY: Bridger-Teton NF    aspen cts               Youngblood & Mueggler 1981
        Medicine NF         forest hts              Alexander & others 1986
        Bighorn Mtns        forest hts              Hoffman & Alexander 1976
        Wind River Mtns     forest hts              Reed 1976

    USFS R-2                general veg. pas        Johnston 1987
    USFS R-2                general veg. hts,pas    Wasser & Hess 1982
    USFS R-4                aspen cts               Mueggler 1988

    w-c AB                  forest cts              Corns 1983
    BC: -----               grassland, forest hts   McLean 1970
        -----               general veg. eas        Pojar & others 1984
    nw BC                   forest eas              Haeussler & others 1985

              

General Ecology

    Broad-scale Impacts of Plant Response to Fire
    provided by Fire Effects Information System Plants
    More info for the term: prescribed fire

    For further information on subalpine fir response to fire, see Fire Case Studies. Hamilton's Research Project Summary and Research Papers
    (Hamilton 2006a, Hamilton 2006b)provide information on prescribed fire and
    postfire response of plant community species, including subalpine fir,
    that was not available when this species review was originally written.
    Fire Ecology
    provided by Fire Effects Information System Plants
    More info for the terms: crown fire, fire regime, forest, frequency, fuel, lichens, tree

    Plant adaptations to fire:  Subalpine fir is very fire sensitive and
    generally suffers high mortality even from low intensity fires.  It
    relies on wind-dispersed seeds which readily germinate on fire-prepared
    seedbeds to colonize burned areas.  The occasional mature tree which
    survives fire, those escaping fire in small, unburned pockets, and trees
    adjacent to burned areas provide seeds to colonize burned sites.  In
    subalpine habitats, scattered subalpine fir trees often escape fire
    because of discontinuous fuels, broken and rocky terrain, and the moist
    and cool environment [78,87,91].

    Fire regime:  Subalpine fir habitat types vary from cold and wet at
    higher elevations to warm and moist or cool and dry at lower elevations.
    This environmental gradient influences the mean fire return interval
    (MFRI).  Relatively dry lower elevation subalpine fir habitat types have
    more frequent and less intense fires than moist middle and upper
    elevation subalpine fir habitat types [12,91].  Such forests in the
    Bitterroot National Forest in Montana have a MFRI of 17 to 28 years
    [14].  Fires at this frequency kill subalpine fir and keep these forests
    dominated by seral conifers such as lodgepole pine, Douglas-fir, or
    western larch.  Moist, middle and upper elevation subalpine fir habitat
    types, however, generally experience high intensity stand-replacing
    fires at intervals of 100 years or more.  Mean fire return intervals for
    middle and upper elevation subalpine fir habitat types in several areas
    are presented below:

    Location                  Community dominants           MFRI    Reference
                                                           (years)
    Kananaskis Park, AB      subalpine fir, spruce,          90       [12]
                             lodgepole pine        
    northern Cascades, WA    subalpine fir                 154        [2]
    northern Cascades, WA    subalpine fir-lodgepole pine  109        [2]
    Olympic NP, WA           subalpine fir                 150        [116]
    Yellowstone NP, WY       subalpine fir                 300-350    [98]
    Coram Exp. Forest, nw MT western larch, Douglas-fir,   117-146    [129]
                             lodgepole pine, subalpine fir

    Fuels and fire behavior:  The fuel structure in subalpine-fir-dominated
    stands promotes highly destructive stand-destroying fires.  Fuel loads
    in subalpine fir stands are greater than in lower elevation montane
    stands because the cool and moist environment slows the decomposition of
    organic matter allowing fuels to accumulate more rapidly [1].  Fuel beds
    tend to be irregular, with over twice as much fuel accumulating under
    the narrow-crowned trees as between them [116].  The needles are small
    and fine and form a compact fuel bed in which fire spreads slowly [34].
    These concentrated, slow burning fuels frequently produce flames high
    enough to reach subalpine fir's low-growing dead branches [116].  Thus
    crowning is common in subalpine fir stands.

    Once a crown fire begins, it spreads easily because subalpine fir has a
    tendency to grow in dense stands and has highly flammable foliage.  A
    lightning strike on May 7, 1987, in a subalpine fir-mountain hemlock
    stand in Mount Rainier National Park started a crown fire even though
    the ground was still partially snow covered.  The fire spread slowly
    through the tree crowns by (1) igniting lichens draped along the fine
    branches, (2) preheating and igniting the foliage, and (3) spreading to
    a nearby tree by igniting its lichens [62].

    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".
    Fire Management Considerations
    provided by Fire Effects Information System Plants
    Subalpine fir is very fire sensitive and is often killed even by surface
    fires.  Following timber harvest, on sites where subalpine fir is not a
    preferred species, light surface fires may be used to kill subalpine
    fir and promote the establishment of other conifers [93]. 

    Fuels remain moist in many high elevation subalpine fir habitat types
    during most of the year, leaving only a short time period during certain
    years when prescribed burning can take place [63,91].

    Subalpine fir seeds germinate poorly in soils under burned slash piles
    [130] but readily germinate on mineral soil seedbeds prepared by
    broadcast burning [16,107].
    Fire Management Implications
    provided by Fire Effects Information System Plants
    More info for the terms: cone, seed

    High intensity crown fires which are common in subalpine fir forests,
    kill all or nearly all seed trees within a burned area.  If subalpine
    fir is to naturally regenerate on this type of burn, seeds must come
    from adjacent unburned stands.  Because subalpine fir seeds are
    dispersed over relatively short distances, initial seedling
    establishment is restricted to the burn's edge.  Subalpine fir cone
    production can be erratic from year to year, with the best regeneration
    occurring during good seed crop years.
    Growth Form (according to Raunkiær Life-form classification)
    provided by Fire Effects Information System Plants
    More info on this topic.

    More info for the terms: phanerophyte, therophyte

       Undisturbed State: Phanerophyte (mesophanerophyte)
       Undisturbed State: Phanerophyte (microphanerophyte)
       Undisturbed State: Phanerophyte (nanophanerophyte) Krummholz form
       Burned or Clipped State: Therophyte
    Immediate Effect of Fire
    provided by Fire Effects Information System Plants
    More info for the term: lichen

    Subalpine fir is one of the least fire-resistant western conifers.  It
    is very susceptible to fire because it has (1) thin bark that provides
    little insulation for the cambium, (2) bark which ignites readily, (3)
    shallow roots which are susceptible to soil heating, (4) low-growing
    branches, (5) a tendency to grow in dense stands, (6) highly flammable
    foliage, and (7) moderate to heavy lichen growth [37,111].

    Subalpine fir forests are normally subject to highly destructive crown
    fires that occur at 100-year or longer intervals.  Such fires typically
    kill all subalpine fir trees.  Subalpine fir is also very susceptible to
    surface fires because fine fuels which are often concentrated under
    mature trees burn slowly and girdle the thin-barked bole [34].
    Life Form
    provided by Fire Effects Information System Plants
    More info for the term: tree

    Tree
    Plant Response to Fire
    provided by Fire Effects Information System Plants
    More info for the terms: cone, seed, tree, wildfire

    Following fire, subalpine fir reestablishes via seeds dispersed by wind
    from trees surviving in protected pockets or from trees adjacent to
    burned areas.  Subalpine fir readily establishes on burned mineral soil
    seedbeds [107].  Ash does not affect germination, but if it is deep, it
    can prevent a seedling's roots from reaching mineral soil [85].
    Although seedling establishment is often favored by shade, it will
    establish in full sunlight following fire [87].

    The rate of establishment is quite variable, and depends on the
    proximity of the seed source (because the heavy seeds are dispersed over
    short distances) and seed production during the year of the fire and
    immediate postfire years.  In general, subalpine fir seedling
    establishment is very slow in areas suffering large, continuous crown
    fires but is relatively rapid on small burned-over areas where a seed
    source is nearby [90,124,128].  Three years after a late August wildfire
    in northern Colorado, in a dense, mature stand composed of Engelmann
    spruce, subalpine fir, and lodgepole pine, subalpine fir had established
    15,200 seedlings per acre (37,500/ha) on small burns that were less than
    one-tenth of an acre in size.  But on areas within the middle of the
    main burn, subalpine fir had established only 12 seedling per acre
    (30/ha) 3 years after the fire [16].  In Colorado, Peet [90] found a
    75-year-old burn that had few conifer seedlings even though an
    old-growth subalpine fir-Engelmann spruce stand was 218 yards (200 m)
    away.

    Reinvasion into large burns is slow because much of the seed source is
    destroyed.  However, sometimes sporadic survivors provide a limited seed
    source so that a small number of seedlings establish quickly following
    fire.  When this occurs, large quantities of seeds are dispersed several
    decades later as the early invading seedlings mature and reach cone
    bearing age [128].

    On areas where subalpine fir is abundant and lodgepole pine scarce
    before burning, subalpine fir establishes quickly following fire if
    sufficient numbers of seed trees survive or are near the burn.  However,
    if lodgepole pine is present prior to burning, it usually seeds in
    aggressively and assumes a dominant role because it quickly overtops any
    fir seeding in at the same time [34].  Subalpine fir can be suppressed
    for several decades in seral lodgepole stands which develop following
    fire; one-hundred-year-old individuals may be only 3 feet (0.9 m) tall
    [90].  It may take 50 to 150 years after a fire for substantial
    subalpine fir establishment under dense lodgepole pine stands
    [18,109,128].

    In the Olympic Mountains, tree seedling establishment following fires in
    closed mountain hemlock-subalpine fir forests was higher during wet
    growing seasons than during dry growing seasons.  Establishment rates
    were higher near the edge of a fire or near survivors than in areas
    removed from a seed source [4].  On many burned areas, subalpine fir did
    not establish seedlings for several years because of poor seed crops.
    On some burns there was a lag time of 40 to 50 years after fire before
    there was substantial seedling establishment.  This was a result of
    early invading trees maturing and dispersing seeds [4].

    High elevation subalpine fir stands that have burned often remain open
    for several decades or more [18,31].  The harsh environment near
    treeline makes it difficult for tree seedlings to establish and survive
    [18].  Grasses and sedges may form a mat in subalpine meadows which
    prevents tree seeds from reaching mineral soil [109].
    Post-fire Regeneration
    provided by Fire Effects Information System Plants
    More info for the terms: secondary colonizer, seed

       crown-stored residual colonizer; short-viability seed in on-site cones
       secondary colonizer; off-site seed carried to site after year 2
       off-site colonizer; seed carried by wind; postfire years 1 and 2
    Regeneration Processes
    provided by Fire Effects Information System Plants
    More info for the terms: climax, duff, forest, layering, litter, natural, seed, stratification, tree

    Cone and seed production:  Subalpine fir can begin producing cones when
    20 years old and 4 or 5 feet (1.2-1.5 m) tall, but under closed forest
    conditions seed production is generally not significant until trees are
    older and taller [11].  Corkbark fir generally does not produce cones
    until about 50 years old [39].  Nearly all cones are produced on the
    uppermost part of the crown.  Maximum seed production is by dominant
    trees between 150 and 200 years old [39].  Yearly seed production is
    very erratic; good seed crops are produced every 3 to 5 years, with
    light crops or crop failures in between [39,40,54,86].  Corkbark fir is
    also a poor seed producer, having more crop failure years than good seed
    crop years [9].  Subalpine fir averages 34,800 seeds per pound
    (76,700/kg), while corkbark fir seeds average 22,300 per pound
    (49,150/kg) [41].

    Seed predation:  Insect pests reduce seed yields by feeding on cones and
    seeds; however, the magnitude of loss is variable [11].  Red squirrels
    cut and cache large quantities of subalpine fir cones [9].  After
    dispersal, numerous small rodents and birds consume seeds from the
    ground.

    Dispersal:  Mature subalpine and corkbark fir seeds have a large wing
    and are dispersed primarily by wind in the fall as cones disintegrate on
    the tree.  Seeds travel primarily in the direction of prevailing winds,
    but upslope drafts can influence dispersal at low and middle elevations
    [9].  Studies in Colorado showed that about one-half of subalpine fir
    seeds dispersed into clearcuts fell within 100 feet (30 m) of the
    clearcut's windward edge, while the remainder fell within 260 feet (80
    m) of the edge [86].  Some seeds are also dispersed by red squirrels
    which cut and cache cones before they disintegrate; seeds commonly
    germinate from these middens, forming thickets [71].

    Germination and viability:  Seeds overwinter under or in snow.  This
    cold, moist stratification is required for germination [41].
    Germination begins in the spring a few days after snowmelt and is
    usually completed within a few weeks [9,106].  Percent germination is
    low due to unsound seed; about 31 to 38 percent for subalpine fir and 26
    to 33 percent for corkbark fir [39,41].  Under natural conditions seeds
    remain viable for 1 year [41].  Stratification procedures for stored
    seeds have been described in detail [41,74].

    Seedling establishment and survival:  Seedlings establish best on
    mineral soil seedbeds but will also establish on other surfaces
    including litter, duff, and decaying wood [11].  Because Engelmann
    spruce requires a mineral soil seedbed, subalpine fir seedlings usually
    outnumber spruce seedlings in the understory of spruce-fir stands.
    Thus, even though it is short-lived, many ecologists consider subalpine
    fir better able to regenerate under climax conditions than Engelmann
    spruce.  Subalpine fir is very shade tolerant and easily establishes
    under a closed canopy.  Throughout the Rocky Mountains subalpine fir is
    reproducing abundantly under conditions of dense shade and is often
    abundant as seedlings and saplings in spruce-fir forests, even where
    Engelmann spruce dominates the overstory [11,67].

    At higher elevations, seedling survival is sometimes greater on duff
    seedbeds because the duff helps protect seedlings from high-intensity
    summer rain storms and frost heaving [35].  At lower elevations,
    seedling densities are often greater on mineral soils [35].  In a
    spruce-fir forest in southeastern Wyoming, Knapp and Smith [67] found
    that 42 percent of subalpine fir seedlings were on litter deeper than 1
    inch (2.5 cm), compared with only 5 percent of Engelmann spruce
    seedlings.  Subalpine fir is able to establish in duff because of its
    rapid root growth.  Comparing seedlings grown in a greenhouse, subalpine
    fir's taproot length (29 mm) 2 weeks after germination was over 200
    percent greater than the taproot length of Engelmann spruce (9.4 mm)
    [67].

    Growth:  Subalpine fir seedlings grow very slowly.  One-year-old
    seedlings are frequently less than 1 inch (2.5 cm) tall [11].  One study
    found 15-year-old seedlings averaged only 11 inches (28 cm) in height on
    burned-over slopes, 10 inches (25 cm) on cut-over dry slopes, and 6
    inches (15 cm) on cut-over wet flats [11].  Under favorable conditions
    trees reach a height of 4 to 5 feet (1.2-1.5 m) in 20 to 40 years [11].
    Under a closed canopy, trees 4 to 6 feet tall (1.2-1.8 m) are often 35
    to 50 years old.

    Vegetative reproduction:  Near timberline subalpine fir frequently
    reproduces by layering, probably as a result of heavy snow, wind, and
    cold temperatures which restrict growth away from the ground.  Layering
    often results in clusters of subalpine fir growing near timberline [13].
    Under closed forest canopy, reproduction by layering is negligible.
    Season/Severity Classification
    provided by Fire Effects Information System Plants
    fall/severe
    Site Description
    provided by Fire Effects Information System Plants
    More info for the terms: duff, fuel, snag

    The burned site is a southwest facing gentle slope at an elevation of
    5,596 to 5,776 feet (1,706-1,761 m).  A total of 27 acres (10.9 ha) were
    burned. 

    Climate:  The climate is typical of most areas within the subalpine
    zone.  The winters are cold and wet and the summers cool and dry.  Frost
    and freezing temperatures can occur during any month of the year.  Over
    70 percent of precipitation falls as snow between October and March.

    Soil and duff:  The two stands have similar soils, but the soil in the
    snag area is more fertile and better developed.  In both areas soils
    are derived from basalt residium, have a clay-loam texture, and average
    6 inches (15.2 cm) deep.  The effective rooting depth was about 20
    inches (51 cm) in the thicket area, and 20 to 40 inches (51-102 cm) in
    the snag area.  On both areas, duff was generally from 1 to 4 inches
    (0.4-1.6 cm) thick.  The mean depth of duff was 2.3 inches (5.94 cm) on
    the thicket area, and 1.9 inches (4.92 cm) on the snag area. 

    Fuel loading:  Prior to burning, mean fuel loads were as follows:

              fuels                    thicket area          snag area
                                    tons/acre tonnes/ha  tons/acre tonnes/ha

    dead and down wood
     0.0-0.25 inch (0.0-0.6 cm)        0.6       1.3        0.9       2.0
     0.26-0.99 inch (0.61-2.5 cm)      2.1       4.6        2.9       6.4
     1.0-3.0 inches (2.6-7.6 cm)       4.4       9.8        5.1      11.4
     > 3.0 inches (7.6 cm) rotten     17.4      38.9       30.9      69.2
     > 3.0 inches (7.6 cm) solid      17.0      38.1       50.1     112.2
    litter                            41.4      92.7       89.8     201.2
    duff                              32.5      72.8       30.0      67.1
    Successional Status
    provided by Fire Effects Information System Plants
    More info on this topic.

    More info for the terms: climax, herbaceous, seed, severity, succession

    In the Rocky Mountains, subalpine fir is a shade-tolerant climax species
    favored by long fire-free intervals.  Its seedlings outcompete spruces,
    lodgepole pine, and Douglas-fir when light intensities are less than 50
    percent of full sunlight, but cannot compete with these conifers under
    brighter light [11].  In Montana and Idaho and in the mountains of
    eastern Washington and eastern Oregon, subalpine fir often forms pure
    stands at climax, but it may also mix with Engelmann spruce, which,
    although considered to be seral to subalpine fir, outlives it and
    persists to climax.  In the Rocky Mountains north and south of Montana
    and Idaho, Engelmann spruce and subalpine fir may codominate at climax
    [11].

    Throughout much of the Cascade Mountains subalpine fir grows as a
    shade-intolerant, seral species and is gradually replaced by more
    shade-tolerant associates such as Pacific silver fir, grand fir, and
    mountain hemlock [43].  It often invades recently disturbed areas with
    lodgepole pine.  It also pioneers harsh sites on raw geologically young
    surfaces such as lava flows and talus slopes and on climatically harsh
    sites near timberline [43].

    In areas where subalpine fir is a climax dominant, succession following
    disturbance varies depending upon the severity and type of disturbance,
    elevation, and the availability of conifer seeds.  Subalpine fir may
    establish immediately following disturbances if mature trees survive to
    provide seeds and seral species such as lodgepole pine and aspen are
    scarce.  Near treeline, it may take 100 years or more for subalpine fir
    to establish seedlings following fire because an increase in herbaceous
    species prevents seeds from reaching mineral soil and the harsh climate
    kills many seedlings that do establish [18,109].  Aspen and lodgepole
    pine are the most common seral species.  They often form pure stands and
    completely dominate low and middle elevation stands within the subalpine
    fir zone following large fires [5,68].  These species grow rapidly and
    quickly overtop any subalpine fir seedlings that may establish at the
    same time.  Aspen stands can sometimes persist for decades or even
    centuries when conifer seed trees are eliminated [29].  When lodgepole
    pine establishes immediately following stand-destroying fires, it often
    forms even-aged dense stands that dominate for 100 to 300 years.
    Because it is very shade tolerant, subalpine fir eventually establishes
    under the pine canopy, usually within 100 years, and attains dominance
    as the pine stand begins to break up [90,98].

    In many of the warmer and lower elevation subalpine fir habitat types,
    subalpine fir has not achieved climax dominance because of repeated
    fires which favor shade-intolerant seral conifers.  Many of these
    habitat types are in midsuccessional stages.  Lodgepole pine, western
    larch, western white pine, or Douglas-fir dominate the overstory, but
    subalpine fir seedlings and saplings occur in the understory [93,113].

Cyclicity

    Phenology
    provided by Fire Effects Information System Plants
    More info on this topic.

    More info for the terms: cone, phenology, seed

    Subalpine fir requires 2 years to complete its reproductive cycle [115].
    Cones are initiated in the spring of the first year as microscopic
    primordia within vegetative buds.  Bud differentiation occurs in
    midsummer, and separate seed-cone and pollen-cone buds develop until
    each becomes dormant in the fall [115].  During the spring of the second
    year, cone buds resume growth and conelets are recognizable in the early
    spring.  During the second year, reproduction phenology generally
    proceeds as follows:

    Phenological event  Location      Timing of event           Reference

    flowering           sw MT, nw WY   mid-June - early July    
    cones full size         "               late August         
    seeds dispersed         "         early Sept - early Oct     [41,101]

    flowering           nw MT, n ID   mid-June - early July     
    cones full size         "         late July - early Aug     
    seeds dispersed         "               mid-Sept             [41,101]

    flowering               OR         late May - early July    
    seed dispersal          "             early Oct               [41]

    male bud burst      Linn, OR         early to mid-May       
    female bud burst        "            mid to late May        
    pollen shed             "                 June              
    seed dispersal begins   "              early October          [45]

    flowering        AZ, San Fran.Peaks     late June           
    cone ripening           "           mid-Sept - early Oct    
    seed dispersal          "           late Sept - early Oct     [41]

Management

    Management considerations
    provided by Fire Effects Information System Plants
    More info for the terms: seed, seed tree, selection, tree, tussock, woodland

    Timber harvest:  Shelterwood and individual tree selection silvicultural
    methods favor subalpine fir over Engelmann spruce, lodgepole pine (Pinus
    contorta), and Douglas-fir (Pseudotsuga menziesii); clearcutting and
    group selection cutting favor subalpine fir over Pacific silver fir
    (Abies amabilis), grand fir (A. grandis), and mountain hemlock (Tsuga
    mertensiana) where they grow together [11].  The seed tree method is
    generally not used because of the susceptibility of subalpine fir to
    windthrow [11].  In the Rocky Mountains, clearcutting and shelterwood
    cutting have been the most commonly used harvesting methods in
    old-growth Engelmann spruce-subalpine fir stands because these stands
    tend to be even-aged and overmature [8].  Uneven-aged silviculture can
    pose a problem because residual subalpine fir trees damaged during
    thinning operations are susceptible to attack by decay fungi.
    Silvicultural systems and cutting methods for managing subalpine fir
    have been discussed in detail [7,8,9,11].

    Pests and diseases:  Subalpine fir is attacked by numerous insects.  The
    most destructive seem to be the western spruce budworm, western balsam
    bark beetle, and balsam woolly aphid [11].  Subalpine fir is one of the
    most common hosts of the western spruce budworm.  This pest generally
    attacks low and middle elevation subalpine fir forests but is largely
    absent from high elevation forests [21].  The balsam woolly aphid has
    virtually eliminated subalpine fir from some stands in the Cascades
    [11].  Other insect pests include the Douglas-fir tussock moth, western
    black-headed budworm, and fir engraver beetle.

    Subalpine fir is susceptible to annosus root disease, caused by the
    fungus Heterobasidion annosum, which results in root and butt decay.
    Outbreaks of this disease are often centered around large 20-year-old or
    older fir stumps that contain the fungus' fruiting bodies [102].
    Subalpine fir is most seriously affected by this disease in the northern
    and central Rocky Mountains [123], and is affected to a lesser extent in
    the Pacific Northwest [102].  Subalpine fir is susceptible to several
    other wood rotting fungi that cause heart, trunk, butt, or root rots,
    including brown stringy rot, red heart rot, red ring rot, shoestring
    rot, brown cubical rot, white spongy root rot, and white pocket rot
    [39].  Trees weakened by wood rots often become infested by fir engraver
    beetles and usually succumb to windfall and breakage [11].  Fir broom
    rust is another common problem in Engelmann spruce-subalpine fir stands
    and causes bole deformation, spike tops and wind breakage, and makes
    trees more susceptible to decay fungi [11].

    Habitat for threatened and endangered species:  Old-growth subalpine fir
    stands in northern Idaho may provide critical habitat for woodland
    caribou [23].  Numerous subalpine fir habitat types, especially those
    containing huckleberries (Vaccinium spp.), provide critical habitat for
    grizzly bears [127].

Benefits

    Cover Value
    provided by Fire Effects Information System Plants
    More info for the term: cover

    Big game:  Subalpine fir habitat types provide excellent hiding cover
    for deer, elk, mountain goats, moose, and bear [10,113].  Certain low
    elevation subalpine fir forests may be used by elk during calving, and
    high elevation subalpine fir forests by bighorn sheep during lambing and
    lamb rearing [113].  Dense stands provide cool summertime shade for big
    game animals [71].  In Yellowstone National Park, grizzly bear daybeds
    are often found in subalpine fir stands [19].

    Small mammals and birds:  Small subalpine firs provide good year-round
    hiding cover.  Dense thickets of small trees are often nearly
    impenetrable and provide hiding places for small mammals such as
    snowshoe hares and porcupines [13,71].  Blue grouse often overwinter in
    subalpine trees and rely almost exclusively on them for escape cover
    [103].  Subalpine fir snags are used by numerous cavity-nesting birds,
    but are generally less preferred than those of associated conifers
    [105].

    The degree to which subalpine fir provides environmental protection
    during one or more seasons for wildlife species is as follows [30]:

                           CO    MT    WY    UT
    Pronghorn             ----  ----  poor  poor
    Elk                   good  fair  good  good
    Mule deer             good  fair  good  good
    White-tailed deer     ----  ----  poor  ----
    Small mammals         good  good  good  good
    Small nongame birds   good  fair  good  good
    Upland game birds     good  good  good  fair
    Waterfowl             ----  ----  poor  poor
    Importance to Livestock and Wildlife
    provided by Fire Effects Information System Plants
    More info for the terms: cover, woodland

    Subalpine-fir-dominated stands generally do not produce enough forage
    for livestock but do provide browse and cover for large and small
    wildlife species.  Mule deer, elk, moose, woodland caribou, black bear,
    and grizzly bear often use subalpine fir habitats as summer range
    [10,23,113]].  Subalpine fir forests are generally not suitable winter
    range for deer and elk because of heavy snowpack, but some lower
    elevation subalpine fir habitat types are used by moose and woodland
    caribou during the winter [23,61,89].  Subalpine fir forests support
    numerous species of small mammals and birds.  The snowshoe hare, flying
    squirrel, red squirrel, porcupine, pine marten, fisher, lynx, and
    several species of mice, voles, chipmunks, and shrews all inhabit
    subalpine fir forests [26,104,113].  Numerous species of birds nest and
    feed in subalpine fir forests, including several woodpeckers,
    flycatchers, kinglets, nuthatches, juncos, thrushes, chickadees,
    crossbills, the pine siskin, owls, and grouse [104,113].

    The young growth of subalpine fir is sometimes eaten by mule deer, elk,
    bighorn sheep, and snowshoe hares, but it is not an important food item.
    Subalpine fir comprises only a small portion of the summer diet of
    mountain goats but can be a major food source in the winter and spring
    [99].  Throughout much of Montana, Idaho, and Wyoming, subalpine fir is
    an important winter food of moose [89].  On moose winter range near
    Jackson Hole, Wyoming, an average of 13 to 18 percent of small subalpine
    fir trees were browsed by moose, and 44 to 78 percent of the branches on
    trees browsed were utilized [61].  In Yellowstone National Park, grizzly
    bears sometimes strip the bark of subalpine fir to feed on the
    underlying cambium [19].  The winter diet of blue grouse consists
    primarily of conifer needles.  These grouse often winter in subalpine
    stands and may feed heavily on the needles and buds of subalpine fir
    [103,113].

    Subalpine fir seeds are eaten by several species of small mammals and
    birds.  Red squirrels eat seeds from cached subalpine fir cones [71].
    Fir seeds are also eaten by chipmunks and mice.  Several birds,
    including chickadees, nuthatches, crossbills, the pine siskin, and the
    Clark's nutcracker remove and eat the seeds from fir cones [49,77].
    Because subalpine fir seeds are large, comprising about 26 percent of a
    cone's weight, they are an energy-efficient food source for small birds
    [49].  Small birds may make considerable use of fir seeds, but their
    foraging is scattered and sporadic throughout subalpine forests [49].
    Nutritional Value
    provided by Fire Effects Information System Plants
    Subalpine fir is low in protein value but fair in energy value [30].
    Percent composition of subalpine fir browse collected near Jackson Hole,
    Wyoming, was as follows [61]:

      date              crude        ether       crude      nitrogen
    collected          protein      extract      fiber    free extract
     11/25              5.57         7.53        20.19      50.26

    A study in Montana found the following concentration of elements in
    subalpine fir needles and twigs [110]:

          1-yr-old green needles    twigs < 0.25 inch (0.64 cm) in diameter
         (micrograms/gram [mean])           (micrograms/gram [mean])
    Ca             9722                               5840
    Cu                7.4                                7.9
    Fe               64                                182
    K              5553                               7031
    Mg              819                               1038
    Mn             1020                                587
    N             10690                               4962
    Na              103                                124
    P              1450                               2254
    Zn               43                                  5
              (percent [mean])                    (percent [mean])
    Ash               3.5                                3.5
    Other uses and values
    provided by Fire Effects Information System Plants
    Subalpine fir is sometimes used as a landscape plant to produce
    screenings or windbreaks [114].  In the Pacific Northwest it is
    sometimes transplanted into rock gardens or simulated subalpine settings
    [69].

    Native Americans used various parts of subalpine fir for numerous
    purposes.  A hair tonic was prepared by mixing powdered needles with
    deer grease.  Finely ground needles were also sprinkled on open cuts.
    Sticky resin collected from the bark was boiled and used as an
    antiseptic for wounds or as a tea for colds.  Boughs were placed in
    rooms for their aroma, and pulverized needles were used as a body scent
    or as perfume for clothing [53].

    Resin from the bark is used in the optical industry and in laboratories
    as a cement for lenses and microscope slides [71].
    Palatability
    provided by Fire Effects Information System Plants
    The palatability of subalpine fir to domestic livestock is low [30].
    Its palatability to big game animals is generally low also, but in some
    locations it is highly palatable to moose and mountain goats during
    winter and spring [89,99].  The seeds are palatable to numerous small
    mammal species [77].  Red squirrels generally eat subalpine fir seeds
    after other cached conifer seeds have been consumed [71].  The needles
    are highly palatable to blue grouse.

    The relish and degree of use shown by livestock and wildlife species for
    subalpine fir in several western states is rated as follows
    [30,61,89,96]:

                           CO    MT    WY    UT    ID
    Cattle                poor  poor  poor  poor  ----
    Sheep                 poor  poor  poor  poor  ----
    Horses                poor  poor  poor  poor  ----
    Pronghorn             ----  ----  poor  poor  ----
    Elk                   ----  poor  poor  poor  ----
    Moose                 ----  good  good  ----  fair
    Mule deer             ----  poor  poor  poor  ----
    White-tailed deer     ----  ----  poor  ----  ----
    Small mammals         ----  fair  fair  good  ----
    Small nongame birds   ----  ----  fair  good  ----
    Upland game birds     ----  fair  fair  good  ----
    Waterfowl             ----  ----  poor  poor  ----
    Value for rehabilitation of disturbed sites
    provided by Fire Effects Information System Plants
    More info for the terms: forest, seed, tree

    Subalpine fir can be planted on disturbed sites within forest vegetation
    types where it naturally occurs [92].  It is generally recommended for
    cool and moist sites within subalpine areas [120].  Its erosion control
    potential is listed as medium in Utah and Montana, and high in Colorado
    [30].  Because this wide-ranging tree exhibits a large degree of genetic
    variation, seed or nursery stock for rehabilitation projects should come
    from a local source.  Transplanting nursery stock is generally more
    successful than direct seeding [92].  Seedlings exhibit very slow
    initial growth and are therefore usually outplanted as 2- to 3-year-old
    seedlings [41].  Wild seedlings may also be transplanted [120].  A
    maximum spacing of 10 x 10 feet (3 x 3 m) has been recommended for
    seedlings or transplants [120].  Methods for collecting, processing,
    testing, storing, and planting subalpine fir seeds have been discussed
    in detail [32,41].
    Wood Products Value
    provided by Fire Effects Information System Plants
    Subalpine fir wood is odorless, light-weight, soft, and low in bending
    and compressive strength [11].  It is easy to work, glues well, and
    holds nails and screws fairly well.  The wood is primarily used for
    products such as lumber for home construction and for prefabricated wood
    products [9].  Subalpine fir has excellent pulping properties [9].  Use
    for poles and pilings requires large amounts of preservatives because
    the wood decays rapidly [108].

Taxonomy

    Common Names
    provided by Fire Effects Information System Plants
    subalpine fir
    alpine fir
    western balsam fir
    balsam
    white balsam
    balsam fir
    white fir
    Rocky Mountain fir
    pino real blanco
    cork-bark fir
    corkbark fir
    Arizona fir
    Synonyms
    provided by Fire Effects Information System Plants
    Abies balsamea ssp. lasiocarpa (Hook.) Boivin
    Abies balsamea var. fallax (Engelm.) Boivin
    Taxonomy
    provided by Fire Effects Information System Plants
    The genus Abies consists of about 40 species of evergreen trees found in
    the northern hemisphere. Nine species of Abies, including subalpine
    fir, are native to the United States [75]. The currently accepted
    scientific name of subalpine fir is Abies lasiocarpa (Hook.) Nutt.
    [75]. Subalpine fir is widely distributed and exhibits geographic
    variation. Two varieties are recognized based on morphological
    differences [75]:

    Abies lasiocarpa var. arizonica, corkbark fir

    Abies lasiocarpa var. lasiocarpa, typical variety of subalpine fir

    Subalpine fir hybridizes with balsam fir (A. balsamea) where their
    ranges overlap in the Canadian Rockies [41].