Montana Field Guide

These shrublands are dominated by one or more species of low to tall 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.

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)

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

Small Patch and Large Patch

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.

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.

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

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

Information on restoration considerations is lacking at this time.

M.S. Reid and K.A. Schulz 2015

S. Mincemoyer, T. Luna and L. Vance

12/5/2024