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Montane - Subalpine Mesic Shrubland
Global Name: Central Rocky Mountain-North Pacific High Montane Mesic Shrubland

Global Rank: G4G5
State Rank: S5

(see reason below)

External Links




State Rank Reason
These shrublands are relatively common and scattered across the higher mountain ranges. They likely have been relatively stable in extent and condition, experience few, if any widespread and severe threats and generally are not intrinsically vulnerable.
 

General Description
This National Vegetation Classification Group is dominated by one or more species of low to tall, deciduous shrubs in the upper montane and subalpine zones. Shrub cover is often moderate to dense with at most only isolated trees. They are found on both sides of the Continental Divide from southwestern to northwestern Montana, and in the island mountain ranges. They occur most often on moderate to steep mountain slopes, usually on north and east facing aspects, and often occur adjacent to forested communities. In northwestern Montana, elevation ranges from 5,000 to 6,500 feet and up to 8,800 feet in southwestern Montana. Common shrub species include False Huckleberry (Menziesia ferruginea), Twinberry Honeysuckle (Lonicera involucrata), Alderleaf Buckthorn (Rhamnus alnifolia), Bristly Black Currant (Ribes lacustre), Thimbleberry (Rubus parviflorus), Green or Sitka Alder (Alnus viridis), Mountain-ash (Sorbus scopulina and Sorbus sitchensis), Rocky Mountain Maple (Acer glabrum), and Common Huckleberry (Vaccinium membranaceum).

Soils tend to be moist to wet, especially early in the growing season, and they are usually shallow, rocky or gravelly with good aeration and drainage. In northwestern and west-central Montana, it forms within upper montane Douglas-fir (Pseudotsuga menziesii) and Engelmann spruce-subalpine fir (Picea engelmannii/ Abies lasiocarpa) forests on steep slopes and ravines. 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 to the montane zone in places where cold-air ponding occurs, especially on north and east aspects.

This group incorporates the Rocky Mountain Subalpine Deciduous Shrubland Ecological System as well as a portion of the Rocky Mountain Montane-Foothill Deciduous Shrubland Ecological System.

Diagnostic Characteristics
Shrublands; Upper Montane and Subalpine Zones; Upland Sites; Cool, Mesic Settings; Rocky Mountain Region

Typical Dominants: False Huckleberry (Menziesia ferruginea), Twinberry Honeysuckle (Lonicera involucrata), Alderleaf Buckthorn (Rhamnus alnifolia), Bristly Black Currant (Ribes lacustre), Thimbleberry (Rubus parviflorus), Green or Sitka Alder (Alnus viridis), Mountain-ash (Sorbus scopulina and Sorbus sitchensis), Rocky Mountain Maple (Acer glabrum), and Common Huckleberry (Vaccinium membranaceum)

Similar Systems

Range
In Montana, these shrubland communities can be found throughout the higher mountain ranges in the state, including in some of the island ranges as small, scattered patches. The highest concentrations of these communities occur in the northwest portion of the state, east to the Rocky Mtn front and south to the Bitterroot Mountains.

In MT, G305 occurs within these Level III Ecoregions: 15 (Northern Rockies), 16 (Idaho Batholith), 17 (Middle Rockies) and 41 (Canadian Rockies)

In Montana, G305 occurs within these Major Land Resource Areas: 43A-Northern Rocky Mountains and 43B-Central Rocky Mountains

Density and Distribution
Based on 2025 land cover layer. Grid on map is based on USGS 7.5 minute quadrangle map boundaries.



Mapped Distribution by County
Beaverhead, Blaine, Broadwater, Carbon, Cascade, Chouteau, Deer Lodge, Fergus, Flathead, Gallatin, Glacier, Golden Valley, Granite, Hill, Jefferson, Judith Basin, Lake, Lewis and Clark, Liberty, Lincoln, Madison, Meagher, Mineral, Missoula, Park, Phillips, Pondera, Powell, Ravalli, Sanders, Silver Bow, Stillwater, Sweet Grass, Teton, Toole, Wheatland
Based on 2025 land cover layer.

Spatial Pattern
Small Patch and Large Patch

Environment
These shrubland communities occur in relatively cool, mesic, upland habitats in the montane and subalpine zones of all of all the higher mountain ranges across the state. It is found most often on moderate to steep mountain slopes, usually on north and east facing aspects, and it often occurs adjacent to forested communities. In northwestern Montana, elevation ranges from 5,000 to 6,500 feet and up to 8,800 feet in southwestern Montana.

Soils in these communities tend to be moist to wet, especially early in the growing season, and they are often shallow, rocky or gravelly with good aeration and drainage. In northwestern and west-central Montana, it forms within upper montane Douglas-fir (Pseudotsuga menziesii) and Engelmann spruce-subalpine fir (Picea engelmannii/ Abies lasiocarpa) forests on steep slopes and ravines. 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 to the montane zone in places where cold-air ponding occurs, especially on north and east aspects.

Vegetation
These shrubland communities are composed of short to tall-statured shrubs, mostly on mesic sites. Common shrub species include False Huckleberry (Menziesia ferruginea), Twinberry Honeysuckle (Lonicera involucrata), Alderleaf Buckthorn (Rhamnus alnifolia), Bristly Black Currant (Ribes lacustre), Thimbleberry (Rubus parviflorus), Green or Sitka Alder (Alnus viridis), Mountain-ash (Sorbus scopulina and Sorbus sitchensis), Rocky Mountain Maple (Acer glabrum) and Common Huckleberry (Vaccinium membranaceum). Other shrubs that are often present in particular associations within these communities are Serviceberry (Amelanchier alnifolia) and Grouse Whortleberry (Vaccinium scoparium) in higher elevation shrublands. Scattered tree species are often present in some of these communities, species include Quaking Aspen (Populus tremuloides), Balsam Poplar (Populus balsamifera), Subalpine fir (Abies lasiocarpa), and Engelmann Spruce (Picea engelmannii).

On some sites in northwestern Montana, False Huckleberry and Alder can form nearly impenetrable stands. Drier aspects of this community may be dominated by stands of Canada Buffaloberry (Shepherdia canadensis), Birchleaf Spiraea (Spiraea betulifolia) and Snowbrush Ceanothus (Ceanothus velutinus).

The herbaceous understory in these communities is generally sparse on sites with dense shrub cover. More open stands may have significant components of forbs and graminoids. Common graminoids include bluejoint reedgrass (Calamagrostis canadensis), Pinegrass (Calamagrostis rubescens), Geyer's Sedge (Carex geyeri), and blue wildrye (Elymus glaucus). Common forbs and ferns include Beargrass (Xerophyllum tenax), Fireweed (Chamerion angustifolium), and Bracken Fern (Pteridium aquilinum), reflecting the mesic nature of many of these shrublands.

In Montana, this group is represented by 3 Alliances and 10 Associations within the National Vegetation Classification. These likely cover most, if not all the diversity of vegetation types present in the state within this group.

National Vegetation Classification

Download the complete NVC hierarchy for Montana

TT4 B04 Temperate-Boreal Grassland and Shrubland
TT4.b S58 Temperate Grassland and Shrubland
TT4.b1 F116 Temperate Lowland-Montane Grassland and Shrubland
TT4.b1.Ne D022 Western North American Grassland and Shrubland
TT4.b1.Ne.2 M548 Central Rocky Mountain Montane-Foothill Shrubland
TT4.b1.Ne.2.b G305 Central Rocky Mountain-North Pacific High Montane Mesic Shrubland
A3968 Abies lasiocarpa - Populus tremuloides / Acer glabrum Central Rocky Mountain Avalanche Chute Shrubland Alliance
CEGL000984 Abies lasiocarpa - Acer glabrum Avalanche Chute Shrubland
CEGL001061 Acer glabrum Avalanche Chute Shrubland
CEGL001127 Rubus parviflorus / Chamerion angustifolium - Heracleum maximum Shrubland
CEGL005886 Populus tremuloides / Amelanchier alnifolia Avalanche Chute Shrubland
CEGL005889 Ribes lacustre / Chamerion angustifolium Shrubland
A3969 Vaccinium membranaceum - Vaccinium myrtillus - Vaccinium scoparium Montane-Subalpine Shrubland Alliance
CEGL008284 Vaccinium membranaceum - (Sorbus sitchensis) / (Calamagrostis rubescens) Shrubland
A3970 Menziesia ferruginea - Spiraea betulifolia Montane-Subalpine Shrubland Alliance
CEGL005835 Spiraea betulifolia Shrubland
CEGL005879 Vaccinium (myrtillus, scoparium) / Luzula glabrata Dwarf-shrubland
CEGL005888 Menziesia ferruginea / Xerophyllum tenax Shrubland
CEGL005891 Vaccinium membranaceum / Xerophyllum tenax Shrubland
View more information on the NVC standard in Montana
*Disclaimer: Some Alliances and Associations are considered provisional. Some require further documentation to verify their occurrence in the state and some may be modified or deleted in future revisions after collection of additional data and information.

Dynamic Processes
Periodic disturbances such as fire or avalanches are important for maintaining many of these communities.

Management
Extensive stands of huckleberries are important summer and fall foraging areas for grizzly and black bears.

Restoration Considerations
Information on restoration considerations is lacking at this time.

Species Associated with this Community
  • How Lists Were Created and Suggested Uses and Limitations
    Animal Species Associations
    Please note that while all vertebrate species have been systematically associated with vegetation communities, only a handful of invertebrate species have been associated with vegetation communities and invertebrates lists for each vegetation community should be regarded as incomplete. Animal species associations with natural vegetation communities that they regularly breed or overwinter in or migrate through were made by:
    1. 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, Werner et al. 2004, Adams 2003, and Foresman 2012);
    2. Evaluating structural characteristics and distribution of each vegetation community relative to the species' range and habitat requirements;
    3. Examining the observation records for each species in the state-wide point observation database associated with each vegetation community;
    4. Calculating the percentage of observations associated with each vegetation community relative to the percent of Montana covered by each vegetation community 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. Species that only migrate through Montana were only evaluated for migratory habitat use. In general, species are listed as associated with a vegetation community if it contains structural characteristics known to be used by the species. However, species are not listed as associated with a vegetation community if we found no support in the literature for the species’ use of structural characteristics of the community even if point observations were associated with it. If you have any questions or comments on animal species associations with vegetation communities, please contact the Montana Natural Heritage Program's Senior Zoologist.

    Plant Species Associations
    Please note that while diagnostic, dominant, or codominant vascular plant species for a vegetation community have been systematically assigned to those communities and vascular plant Species of Concern were systematically evaluated for their associations with vegetation communities, the majority of Montana’s vascular plant species have not been evaluated for their associations with vegetation communities and no attempt has been made to associate non-vascular plants, fungi, or lichens with vegetation communities. Plant species associations with natural vegetation communities were made in a manner similar to that described above for animals, but with review of Lesica et al. (2022) and specimen collection data from the Consortium of Pacific Northwest Herbaria. If you have any questions or comments on plant species associations with vegetation communities, please contact the Montana Natural Heritage Program's Program Botanist.

    Suggested Uses and Limitations
    Species associations with vegetation communities 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 or predicted habitat suitability models (this information can be requested at: https://mtnhp.mt.gov/requests/), or systematic surveys for species and onsite evaluations of habitat by trained biologists. Users of this information should be aware that the land cover data used to generate species associations is based on satellite imagery from 2016 and was only intended to be used at broader landscape scales. Land cover mapping accuracy is particularly problematic when the vegetation communities 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 vegetation community within its known geographic range, portions of that vegetation community may occur outside of the species' known geographic range.

    Literature Cited
    • Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
    • Consortium of Pacific Northwest Herbaria. https://www.pnwherbaria.org/ Last accessed May 30, 2025.
    • 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.
    • Lesica P., M. Lavin, and P.F. Stickney. 2022. Manual of vascular plants, 2nd Edition. Brit Press. 779 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.

Original Concept Authors
M.S. Reid and K.A. Schulz 2015

Montana Version Authors
S. Mincemoyer, T. Luna and L. Vance

Version Date
12/5/2024


References
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Citation for data on this website:
Montane - Subalpine Mesic Shrubland.  Montana Field Guide.  Retrieved on , from