Great Plains Mesic Mixedgrass Prairie
Global Name:
Northern Great Plains Mesic Mixedgrass Prairie
Global Rank:
G3?
State Rank:
S3
(see reason below)
External Links
State Rank Reason
This group is restricted to eastern MT on more mesic prairie sites that receive or retain more moisture. These sites have historically been converted to agriculture and receive continued threats from additional conversion, grazing practices, invasion by non-native species and climate change.
General Description
This National Vegetation Classification Group is a mixed-grass prairie type that occurs in Montana, primarily in the northeastern and north-central parts of the state in more mesic and productive sites than G331-Great Plains Dry Mixedgrass Prairie. It is much less extensive in the state relative to the Dry Mixedgrass Prairie. It is typically composed of a mix of tall and medium-tall grasses ranging in height from 1 to 3 feet. Shrubs are usually scattered or absent but can form dense, local patches, particularly in swales or low areas. Many Mesic Mixedgrass Prairie sites in Montana were converted to agricultural uses as they are more productive than sites supporting Dry Mixedgrass Prairie. As a result, the remaining sites tend to be more scattered and localized in distribution.
This group includes the more mesic communities of the Great Plains Mixedgrass Prairie Ecological System.
Diagnostic Characteristics
Medium and Tallgrass Prairie; Warm Season Grasses; Grasses >25% Cover; Great Plains Region; Mesic sites; Mesic, Shrubby Sites
Dominants: Big Bluestem (Andropogon gerardii), Indiangrass (Sorghastrum nutans) Western Porcupine Grass (Stipa curtiseta) Little Bluestem (Schizachyrium scoparium), Green Needlegrass (Stipa viridula), Western Wheatgrass (Elymus smithii), Switchgrass (Panicum virgatum) and the medium to tall shrubs: Hawthorns (Crataegus spp.), Serviceberry (Amelanchier alnifolia), Silverberry (Elaeagnus commutata), Silver Buffaloberry (Shepherdia argentea), Chokecherry (Prunus virginiana) and Western Snowberry (Symphoricarpos occidentalis)
Similar Systems
Range
This group occurs in the Great Plains of eastern Montana extending west in scattered patches into north-central Montana. It is most abundant in Daniels, Dawson, Richland, Roosevelt, Sheridan, and Wibaux Counties. Minor patches may occur throughout the Great Plains in mesic sites, such as swales and on northerly aspects in what is otherwise dry mixedgrass prairie.
In Montana, G141 occurs in Level III Ecoregions 42 (Northwestern Glaciated Plains) and 43 (Northwestern Great Plains).
In Montana, G141 occurs or potentially occurs within these Major Land Resource Areas: 52 - Brown Glaciated Plains; 53A - Northern Dark Brown Glaciated Plains; 53B - Central Dark Brown Glaciated Plains; 54 - Rolling Soft Shale Plain, and 58A - Northern Rolling High Plains, Northern Part.
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
Blaine, Carter, Chouteau, Custer, Daniels, Dawson, Fallon, Garfield, Hill, Liberty, Mccone, Musselshell, Petroleum, Phillips, Prairie, Richland, Roosevelt, Rosebud, Sheridan, Toole, Treasure, Valley, Wibaux
Based on 2025 land cover layer.
Spatial Pattern
Large Patch-Matrix
Environment
This group occurs on a wide variety of landforms and in proximity to a diversity of other groups. Climate and growing season length for the region in which it occurs are intermediate to the shortgrass regions to the west and southwest and the tallgrass regions to the east. Soils range from loams, clay loams, silty clays, and clays to more coarse-textured sandy or gravelly soils. Some sites may include an impermeable or semi-permeable, claypan, subsoil layer.
Vegetation
This group is dominated by medium to tall grasses in the western Great Plains, particularly mid-height species such as Green Needlegrass (Stipa viridula), Western Wheatgrass (Elymus smithii), Little Bluestem (Schizachyrium scoparium) and Western Porcupine Grass (Stipa curtiseta), and tallgrasses such as Big Bluestem (Andropogon gerardii), Switchgrass (Panicum virgatum), and Indiangrass (Sorghastrum nutans). Grass cover is generally moderate to dense. Other graminoids such as Prairie Junegrass (Koeleria macrantha), Idaho Fescue (Festuca idahoensis) and Carex inops ssp heliophila are common components in some sites. The group also includes mesic, shrub-dominated sites. Species such as Hawthorns (Crataegus spp.), Serviceberry (Amelanchier alnifolia), Silverberry (Elaeagnus commutata), Silver Buffaloberry (Shepherdia argentea), Chokecherry (Prunus virginiana) and Western Snowberry (Symphoricarpos occidentalis) are the typical dominants or co-dominants. Patches are generally small but are dictated by topographic constraints. Shrub heights are generally 1-3 meters.
In Montana, this group is represented by 5 Alliances and 17 Associations within the National Vegetation Classification. These likely cover the range of vegetation types within this group in Montana.
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.Nf D023 Central North American Grassland and Shrubland
TT4.b1.Nf.3 M051 Great Plains Mixedgrass and Fescue Prairie
TT4.b1.Nf.3.b G141 Northern Great Plains Mesic Mixedgrass Prairie
A2309 Prunus virginiana - Symphoricarpos occidentalis - Elaeagnus commutata Northern Plains Shrubland Alliance
CEGL001093 Crataegus douglasii - (Crataegus chrysocarpa) Shrubland
CEGL001097 Crataegus succulenta Shrubland
CEGL001099 Elaeagnus commutata / Pascopyrum smithii Shrubland
CEGL001131 Symphoricarpos occidentalis Shrubland
CEGL005453 Prunus virginiana Northern Plains Shrubland
A2404 Pascopyrum smithii Northern Clay Grassland Alliance
CEGL002239 Pascopyrum smithii - (Elymus trachycaulus) Clay Pan Wet Prairie
A3590 Shepherdia argentea Wet Shrubland Alliance
CEGL001128 Shepherdia argentea Shrubland
A4029 Hesperostipa curtiseta - Elymus lanceolatus Northern Grassland Alliance
CEGL002253 Hesperostipa curtiseta - Elymus lanceolatus Grassland
CEGL003789 Hesperostipa curtiseta - Pascopyrum smithii Grassland
A4031 Pascopyrum smithii - Nassella viridula North-Central Great Plains Grassland Alliance
CEGL001583 Pascopyrum smithii - Nassella viridula Grassland
CEGL002034 Pascopyrum smithii - Hesperostipa comata Central Mixedgrass Grassland
CEGL002205 Andropogon gerardii - Schizachyrium scoparium Northern Plains Grassland
A4034 Schizachyrium scoparium Northern Mixedgrass Grassland Alliance
CEGL001681 Schizachyrium scoparium - Bouteloua (curtipendula, gracilis) - Carex filifolia Grassland
CEGL001682 Schizachyrium scoparium - Carex inops ssp. heliophila Grassland
CEGL001683 Schizachyrium scoparium - Muhlenbergia cuspidata Grassland
A4382 Andropogon gerardii - Sorghastrum nutans Northern Mixedgrass Grassland Alliance
CEGL001463 Andropogon gerardii - Schizachyrium scoparium Northwestern Plains Grassland
*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
Fire and grazing constitute the primary dynamics affecting this group. Drought can also impact it, in general favoring the shortgrass component at the expense of the midgrasses. With intensive grazing, cool-season exotics such as Kentucky Bluegrass (Poa pratensis) and annual bromes can increase in dominance. Shrub species can also increase in dominance with fire suppression. Conversion to agriculture has substantially decreased the extent of this group in Montana as these sites have higher productivity than other prairie sites.
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:
- 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);
- Evaluating structural characteristics and distribution of each vegetation community 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 vegetation community;
- 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.
- Species of Concern Associated with this Community
Vascular Plants
Mammals
Birds
Reptiles
Amphibians
Invertebrates
- Diagnostic, Dominant, or Codominant Plant Species for this Community
Vascular Plants
- Other Native Species Commonly Associated with this Community
Vascular Plants
Original Concept Authors
S. Menard and J. Drake 2015
Montana Version Authors
S. Mincemoyer
Version Date
12/4/2024
References
