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Montana Field Guide

Montana Field Guides

Great Plains Shrubland

Provisional State Rank: S4
(see reason below)

External Links

State Rank Reason
Overgrazing and oil/gas development are the largest primary threats to this ecosystem; invasive species are secondary and largely accompany the primary threats.

General Description

This ecological system is found from southern Alberta through northern Montana’s glaciated and unglaciated plains, typically at elevations ranging from 1,220 to 1,524 meters (4,000-5,000 feet). It can occur on all aspects but is more common on mesic sites with moderately shallow or deep, fine to sandy loam soils. Often it is located on slopes near breaklands and on the edge of coulees, or on upper terraces of rivers and streams. It differs from the Northwestern Great Plains Mixedgrass Prairie in that shrub cover is more than 10%, although the grass component is similar, and may occur where fire suppression in grasslands has allowed shrubs to establish. Dominant shrubs include serviceberry (Amelanchier alnifolia), skunkbush sumac (Rhus trilobata) snowberry (Symphoricarpos species), silver buffaloberry (Sheperdia argentea ), shrubby cinquefoil (Dasiphora fruticosa ssp. floribunda), silverberry (Elaeagnus commutata) and horizontal rug juniper (Juniperus horizontalis). Silver sage (Artemisia cana ssp. cana) shrublands may occur on flat alluvial deposits on floodplains, terraces or benches, and alluvial fans.

Diagnostic Characteristics
Shrubland, ustic soils, temperate

Similar Systems

This system extends from South Dakota into the prairie provinces of southern Canada, and west into Montana’s glaciated and unglaciated plains, typically at elevations ranging from 1,220 to 1,524 meters (4,000-5,000 feet).

Ecological System Distribution
Approximately 1,663 square kilometers are classified as Great Plains Shrubland in the 2017 Montana Land Cover layers.  Grid on map is based on USGS 7.5 minute quadrangle map boundaries.

Montana Counties of Occurrence
Big Horn, Blaine, Carbon, Carter, Cascade, Chouteau, Fergus, Garfield, Glacier, Golden Valley, Hill, Judith Basin, Lewis and Clark, Liberty, Mccone, Meagher, Musselshell, Park, Petroleum, Phillips, Pondera, Rosebud, Stillwater, Sweet Grass, Teton, Toole, Valley, Wheatland, Yellowstone

Spatial Pattern
Large patch


In Montana, this ecosystem forms within the northwestern Great Plains fescue (Festuca spp.) dominated prairie east of the Continental Divide into the western wheatgrass (Pascopyrum smithii) mixed grass prairie in the north-central Great Plains. Climate is semi-arid, and the growing season is short. It can occur on all aspects but is more common on mesic sites with moderately shallow or deep, fine to sandy loam soils. Often it is located on slopes near breaklands and on the edge of coulees, or on upper terraces of rivers and streams. Soils can be moderately shallow to deep, fine to sandy loam soils.


This system differs from Great Plains Mixed Grass Prairie in that natural shrub cover is greater than 10%, and in some cases may be greater than 50%. It is typically dominated by shrub and dwarf-shrub species such as serviceberry, skunkbush sumac, snowberry, shrubby cinquefoil, silverberry, and horizontal juniper. Silver sage shrublands may occur on flat alluvial deposits on floodplains, terraces or benches, and alluvial fans. Silver buffaloberry or western snowberry shrublands can also be found along stream terraces, rolling uplands, and badlands, or where moisture is more plentiful than on the surrounding landscape, such as in swales, ravines, near streams, and on northwest- to east-facing slopes. Common graminoids include threadleaf sedge (Carex filifolia), Idaho fescue (Festuca idahoensis), rough fescue (Festuca campestris), western wheatgrass, Kentucky bluegrass (Poa pratensis), prairie junegrass (Koeleria macrantha), blue grama (Bouteloua gracilis) and bluebunch wheatgrass (Pseudoroegneria spicata). Kentucky bluegrass (Poa pratensis) and common timothy (Phleum pratense) are common introduced grasses in the northwestern part of the system’s range. Common forbs include yarrow (Achillea millefolium), Indian blanket flower (Gaillarida aristata), prairiesmoke (Geum triflorum), sweetvetch (Hedysarum species), Pennsylvania pellitory (Parietaria pensylvanica), lupine (Lupinus species), scarlet guara (Gaura coccinea), scarlet globe-mallow (Sphaeralcea coccinea), cinquefoil (Potentilla species),and goldenrod (Solidago species).

National Vegetation Classification Switch to Full NVC View

Adapted from US National Vegetation Classification

A0918 Elaeagnus commutata Wet Shrubland Alliance
CEGL001099 Elaeagnus commutata - Pascopyrum smithii Wet Shrubland
A1046 Sarcobatus vermiculatus Intermountain Wet Shrubland Alliance
CEGL001359 Sarcobatus vermiculatus - Artemisia tridentata Wet Shrubland
A1201 Calamovilfa longifolia Sand Prairie Alliance
CEGL001457 Rhus trilobata / Calamovilfa longifolia Shrub Grassland
A1537 Rhus trilobata / Schizachyrium scoparium - Carex filifolia Shrub Grassland Alliance
CEGL001504 Rhus trilobata - Carex filifolia Shrub Grassland
CEGL001506 Rhus trilobata - Schizachyrium scoparium Shrub Grassland
A3963 Amelanchier alnifolia Central Rocky Mountain Montane-Foothill Shrubland Alliance
CEGL001065 Amelanchier alnifolia - Pseudoroegneria spicata / Bunchgrass Shrubland
A3964 Rhus glabra - Rhus trilobata Central Rocky Mountain Montane-Foothill Shrubland Alliance
CEGL001120 Rhus trilobata - Pseudoroegneria spicata Shrub Grassland
CEGL001505 Rhus trilobata - Festuca idahoensis Shrub Grassland
A4035 Juniperus horizontalis - Dasiphora fruticosa ssp. floribunda / Schizachyrium scoparium Shrubland Alliance
CEGL001394 Juniperus horizontalis - Schizachyrium scoparium Dwarf-shrubland
A4036 Prunus virginiana - Symphoricarpos occidentalis - Amelanchier alnifolia Great Plains Shrubland Alliance
A4096 Dasiphora fruticosa ssp. floribunda / Festuca campestris - Festuca idahoensis Shrub-steppe Alliance
CEGL001502 Dasiphora fruticosa ssp. floribunda - Festuca idahoensis Shrub Grassland
CEGL001503 Dasiphora fruticosa ssp. floribunda - Festuca campestris Shrub Grassland
*Disclaimer: Alliances and Associations have not yet been finalized in the National Vegetation Classification (NVC) standard.  A complete version of the NVC for Montana can be found here.

Dynamic Processes
Fire and grazing constitute the primary dynamics affecting this system, although drought has also been an impact in the past decade. All shrub species regenerate well following low to moderate intensity fires by re-sprouting from the root systems. In areas where this system occurs in patches within a mixed grass prairie matrix, heavy grazing impacts can limit productivity of associated graminoids and forbs, leading to the increasing spread of introduced grasses and invasive forbs.

In the absence of natural fire, periodic prescribed burns can be used to maintain this system.

Restoration Considerations
Restoration strategies will depend largely on the severity of impacts. Many shrub species occurring within this system resprout following disturbance, including fire. Because lightly to moderately burned or grazed areas recover quickly, reseeding and replanting is usually not necessary.

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:
    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, Foresman 2012, Adams 2003, and Werner et al. 2004);
    2. Evaluating structural characteristics and distribution of each ecological system 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 ecological system;
    4. 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: 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.

    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.
    • 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.

Original Concept Authors
Natureserve Western Ecology Group

Montana Version Authors
L.K. Vance, T. Luna

Version Date

  • Classification and Map Identifiers

    Cowardin Wetland Classification: Not applicable

    NatureServe Identifiers:
    Element Global ID 28520
    System Code CES303.662, Northwestern Great Plains Shrubland

    National Land Cover Dataset:
    52: Scrub/Shrub

    5262: Northwestern Great Plains Shrubland

  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Erickson, Albert W., and D. B. Siniff. 1963. A statistical evaluation of factors influencing aerial survey results on brown bears. Anchorage, Alaska: Alaska Department of Fish and Game.

    • Hansen, P. L., R. D. Pfister, K. Boggs, B. J. Cook, J. Joy, and D. K. Hinckley. 1995. Classification and management of Montana's riparian and wetland sites. Montana Forest and Conservation Experiment Station, School of Forestry, University of Montana, Miscellaneous Publication No. 54. 646 pp. + posters.

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Citation for data on this website:
Great Plains Shrubland — Northwestern Great Plains Shrubland.  Montana Field Guide.  Retrieved on , from