Rocky Mountain Subalpine Mesic Spruce-Fir Forest and Woodland
Provisional State Rank
These forests are similar to Rocky Mountain Subalpine Dry-Mesic Spruce-Fir Forest and Woodland (4242), but occur in locations with cold-air drainage or ponding, or where snowpacks linger late into the summer, such as north-facing slopes and high-elevation ravines. They are distinguished by their occurrence on mesic to wet microsites within the matrix of the drier (and warmer) subalpine spruce-fir or lodgepole pine forests. The microsites include north-facing slopes, swales or ravines, toeslopes, cold pockets, and other locations where available soil moisture is higher or lasts longer into the growing season. This system can extend down in elevation below the subalpine zone in places where cold-air ponding occurs, especially on north and east aspects. Elevations range from 884 to 1,981 meters (2,900-6,500 feet) west of the Continental Divide, and 1,585 to 2,682 meters (5,200-8,800 feet) east of the Continental Divide. Spruce is usually associated with subalpine fir and occurs either as a climax co-dominant or as a persistent, long-lived seral species in most upper elevation subalpine fir stands. Mountain hemlock (Tsuga mertensiana) occurs as small patches within the matrix of this mesic spruce-fir system, but only in the most maritime of environments of northwestern Montana, in the coldest and wettest sites. The shrub understory contains many ericaceous species such as rusty leaf menziesia (Menziesia ferruginea), dwarf huckleberry (Vaccinium caespitosum), mountain huckleberry (Vaccinium membranaceum), bilberry (Vaccinium myrtillus), grouse whortleberry (Vaccinium scoparium), pink mountain heath (Phyllodoce empetriformis), black twinberry honeysuckle (Lonicera involucrata), gooseberry (Ribesspecies) and thimbleberry (Rubus parviflorus). The herbaceous understory contains mesic forbs, graminoids, and ferns and fern allies on the wettest sites. Moss cover is often high. Stand-replacing fires are less common in mesic spruce-fir forests than in dry-mesic forests.
Forest and woodlands, acidic and udic soils, very long disturbance intervals, long persistence (>500years), Picea engelmannii, Abies lasiocarpa
This system occurs is distinguished by its occurrence on mesic to wet microsites within the matrix of the drier (and warmer) subalpine spruce-fir or lodgepole pine forests. The microsites include north-facing slopes, swales or ravines, toeslopes, cold pockets, and other locations where available soil moisture is higher or lasts longer into the growing season. Engelmann spruce and subalpine fir mesic forests comprise a substantial part of the subalpine forests of the northwestern Montana Rocky Mountains. In Montana, these mesic to wet forests are very common west of the Continental Divide in the Flathead and Kootenai river drainages. The wetter habitat types such as subalpine fir/ devil’s club (Abies lasiocarpa/Oplopanax horridum) and Engelmann spruce/ horsetail (Picea engelmannii/Equisetum arvense) associations are found locally in the Flathead Valley and along Sheep Creek north of White Sulphur Springs.
Ecological System Distribution
Approximately 6,593 square kilometers are classified as Rocky Mountain Subalpine Mesic Spruce-Fir Forest and Woodland in the 2016 Montana Land Cover layers.
Grid on map is based on USGS 7.5 minute quadrangle map boundaries.
Montana Counties of Occurrence
BEAVERHEAD, BROADWATER, CARBON, CASCADE, DEER LODGE, FERGUS, FLATHEAD, GALLATIN, GLACIER, GOLDEN VALLEY, GRANITE, JEFFERSON, JUDITH BASIN, LAKE, LEWIS AND CLARK, LINCOLN, MADISON, MEAGHER, MINERAL, MISSOULA, PARK, PONDERA, POWELL, RAVALLI, SANDERS, SILVER BOW, STILLWATER, SWEET GRASS, TETON, WHEATLAND
This system forms a belt at relatively low to high elevations west of the Continental Divide and mid to high elevations east of the Divide throughout the Montana Rocky Mountains and rarely, in the island ranges of north-central and west-central Montana. Elevations range from 884 to 1,981 meters (2,900-6,500 feet) west of the Continental Divide, and 1,585 to 2,682 meters (5,200-8,800 feet) east of the Continental Divide. Soils are derived from a variety of parent materials. They are usually rocky or gravelly with good aeration and drainage, but are usually acidic. Occurrences are typically found in locations with cold-air drainage or ponding, or where snowpacks linger late into the summer, such as north-facing slopes and high-elevation ravines. They can extend down in elevation below the subalpine zone in places where cold-air ponding occurs, especially on north and east aspects.
Tree canopy characteristics are relatively uniform, with Picea and Abies dominating either mixed or alone. Engelmann spruce is more tolerant of extreme environmental conditions than subalpine firs, and is usually more dominant in the drier and wettest occurences within this system. Mountain hemlockoccurs as small to large patches within the matrix of this mesic spruce-fir system but only in the most maritime of environments of northwestern Montana, in the coldest and wettest sites.
The understory of Picea -Abies forests in northwestern Montana often supports diverse stands of ericaceous plants, such as rusty leaf menziesia, dwarf huckleberry, mountain huckleberry, bilberry and mountain heath. Grouse whortleberry and Labrador tea (Ledum glandulosum) are common on mesic sites.Cascade azalea (Rhododendron albiflorum) occurs in association with mountain hemlock and subalpine fir in some occurrences in northwestern Montana.Other common shrubs include Rocky Mountain maple (Acer glabrum), serviceberry (Amelanchier alnifolia), black twinberry honeysuckle, currant (Ribes species), thimbleberry, shortfruit willow (Salix brachycarpa) and greyleaf willow (Salix glauca). In the wettest subalpine fir forests in northwestern Montana, devil’s club is a major shrub associate. These sites are usually restricted to ravine bottoms near streams and seeps where the water table remains near the surface all year. The herbaceous layer is typically diverse. Smooth woodrush (Luzula glabrata var. hitchcockii), bluejoint reedgrass (Calamagrostis canadensis), and pinegrass (Calamagrostis rubescens) are the most commonly associated graminoids. On moist sites with seeps or adjacent to running water, a lush herbaceous understory is present. Forb species includebaneberry (Actaea rubra), marsh marigold (Caltha leptosepala), queen’s cup beadlily (Clintonia uniflora), bunchberry dogwood (Cornus canadensis),starry Solomon’s seal (Maianthemum stellatum), sidebellswintergreeen (Orthothilla secunda), arrowleaf groundsel (Senecio triangularis), clasp-leaf twisted stalk (Streptopus amplexifolius), foamflower (Tiarella trifoliata), western meadow rue (Thalictrum occidentale), Sitka valerian (Valeriana sitchensis), green false hellebore (Veratrum viride), and beargrass (Xerophyllum tenax). Ferns and fern allies such ashorsetail (Equisetum species), oakfern (Gymnocarpium dryopteris) and ladyfern (Athyrium species) form dense cover, inespecially wet spruce habitats on flat sites with poor drainage. Moss cover is often high within these forests.
Alliances and Associations
- (A.311) Black Cottonwood Temporarily Flooded Forest Alliance
- (A.164) Engelmann Spruce Forest Alliance
- (A.191) Engelmann Spruce Seasonally Flooded Forest Alliance
- (A.3535) Fireweed Herbaceous Alliance
- (A.146) Mountain Hemlock Forest Alliance
- (A.603) Paper Birch Woodland Alliance
- (A.168) Subalpine Fir - Engelmann Spruce Forest Alliance
- (A.422) Subalpine Fir - Quaking Aspen Forest Alliance
- (A.190) Subalpine Fir Seasonally Flooded Forest Alliance
- (A.559) Subalpine Fir Woodland Alliance
Major disturbances include occasional blowdown, insect outbreaks (30-50 years), mixed-severity fire, and stand-replacing fire (every 150-500 years) (Arno 1980). The more summer-dry climatic areas also have occasional high-severity fires. Insects and diseases can play a major role in the successional direction of these forests. Throughout Montana, subalpine fir and spruce are affected by spruce bud worm attacks, and large stands of these subalpine forests can be killed following several years of drought or unusually mild winters. Following fire, spruce is more successful at establishing on mineral soils. Subalpine fir, in contrast, is better at establishing in the shade and on organic substrates. In forests undisturbed by fire or subjected to spruce budworm attacks, subalpine fir assumes greater dominance. Over a period of 500 years, subalpine fir will largely replace spruce within most habitats of this system, with the exception of the wettest sites.
In the absence of natural fire, periodic prescribed burns can be used to maintain this system.
The wetter habitat types within this system are usually not subjected to stand-replacing fires. However, crown fires do occur when large, stand-replacing fires in adjacent drier forests travel into these habitats
Species Associated with this Ecological System
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
- Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if
point observations were associated with that system.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: http://mtnhp.org/requests/default.asp
) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.
- Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
- Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
- Foresman, K.R. 2012. Mammals of Montana. Second edition. Mountain Press Publishing, Missoula, Montana. 429 pp.
- Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
- Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
- Maxell, B.A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
- Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
- Native Species Commonly Associated with this Ecological System
- Native Species Occasionally Associated with this Ecological System
Original Concept Authors
Montana Version Authors
- Classification and Map Identifiers
Cowardin Wetland Classification:
National Vegetation Classification Standard:
||Mesomorphic Tree Vegetation (Forest and Woodland)
||Cool Temperate Forest
||Western North America Cool Temperate Forest
||Rocky Mountain Subalpine and High Montane Conifer Forest
National Land Cover Dataset:
|Element Global ID
||CES306.830, Rocky Mountain Subalpine Mesic Spruce-Fir Forest and Woodland
42: Evergreen Forest
4243: Rocky Mountain Subalpine Mesic Spruce-Fir Forest and Woodland
- Literature Cited AboveLegend: View Online Publication
- Alexander, R.R. and W.D. Shepperd. 1990. Picea engelmannii Parry ex Engelm. Silvics of North America 1:187-203.
- Bebi, P., D. Kulakowski, and T.T. Veblen. 2003. Interactions between fire and spruce beetles in a subalpine Rocky Mountain forest landscape. Ecology 84(2):362-371.
- Dupont, A., L. Bélanger, and J. Bousquet. 1991. Relationships between balsam fir vulnerability to spruce budworm and ecological site conditions of fir stands in central Quebec. Canadian Journal of Forest Research 21(12):1752-1759.
- Jenkins, M.J., E.G. Hebertson, and A.S. Munson. 2014. Spruce beetle biology, ecology and management in the Rocky Mountains: an addendum to spruce beetle in the rockies. Forests 5(1):21-71.
- Kulakowski, D. and T.T. Veblen. 2006. The effect of fires on susceptibility of subalpine forests to a 19th century spruce beetle outbreak in western Colorado. Canadian Journal of Forest Research 36(11):2974-2982.
- Lindemann, J.D. and W.L. Baker. 2001. Attributes of blowdown patches from a severe wind event in the Southern Rocky Mountains, USA. Landscape Ecology 16(4):313-325.
- Reinhardt, E. and L. Holsinger. 2010. Effects of fuel treatments on carbon-disturbance relationships in forests of the northern Rocky Mountains. Forest Ecology and Management 259(8):1427-1435.
- Tesky, J.L. 1992. Tsuga mertensiana. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.
- U.S. Department of Agriculture, Forest Service, Missoula Fire Sciences Laboratory. 2012. Information from LANDFIRE on Fire Regimes of Rocky Mounatin Subalpine Mixed-Conifer Communities. In: Fire Effects Information System, [Online]. U.S. Department of Agr
- Uchytil, R.J. 1991. Abies lasiocarpa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Arno, S. F. 1980. Forest fire history in the northern Rockies. Journal of Forestry 78(8):460-465.
- Pfister, R. D., B. L. Kovalchik, S. F. Arno, and R. C. Presby. 1977. Forest habitat types of Montana. USDA Forest Service. General Technical Report INT-34. Intermountain Forest and Range Experiment Station, Ogden, UT. 174 pp.