Great Plains Saline Marsh and Wet Meadow
Global Name:
Great Plains Saline Wet Meadow & Marsh
Global Rank:
GNR
State Rank:
S4
(see reason below)
External Links
State Rank Reason
Overall condition, threats and trends of this group are poorly known or documented. However, these habitats are widespread, and they do not appear to be particularly vulnerable or threatened at this time.
General Description
This National Vegetation Classification Group contains mostly small and isolated saline marshes and depressional wetlands as well as streamside communities within the Great Plains Region of central and eastern Montana. These are intermittently, seasonally or semi-permanently flooded, usually retaining water into the growing season. Sites have clay soils with an accumulation of salts. They are sparsely to densely-vegetated by herbaceous species tolerant of saline conditions. Typical species include Saltgrass (Distichlis spicata), Western Wheatgrass (Pascopyrum smithii), Nuttall's Alkaligrass (Puccinellia nuttalliana), Foxtail Barley (Hordeum jubatum), Alkali Sacaton (Sporobolus airoides), Cordgrass (Spartina spp), Spikerushes (Eleocharis spp), Western Glasswort (Salicornia rubra), and Black Greasewood (Sarcobatus vermiculatus). The presence and abundance of various species and communities depends in large part on the local hydrology and salinity. Sites occur within the matrix of mixed grass prairie primarily in small depressions and flats. The high salinity of these sites is attributed to the high evaporation and the accumulation of minerals dissolved in the water. Wetlands in this group are discharge wetlands, where water high in dissolved salts has moved from the regional groundwater system into the depression. Hydroperiods vary depending on precipitation and snowmelt, which are the primary sources of water. Water is prevented from percolating out of the depression due to impermeable dense clay, and salt encrustations can occur on the surface with drying.
This group encompasses portions of the Emergent Marsh, Great Plains Closed Depressional Wetland, Great Plains Saline Depression Wetland, and the Greasewood Flat Ecological Systems.
Diagnostic Characteristics
Saline Wetlands; Marsh and Wet Meadow; Herbaceous or Shrub Dominated; Great Plains Region; Seasonally, Vernally or Permanently Saturated; Hydric Soils; High Clay Contents.
Typical Dominants: Saltgrass (Distichlis spicata), Western Wheatgrass (Pascopyrum smithii), Nuttall's Alkaligrass (Puccinellia nuttalliana), Foxtail Barley (Hordeum jubatum), Alkali Sacaton (Sporobolus airoides), Cordgrass (Spartina spp), Spikerushes (Eleocharis spp), Western Glasswort (Salicornia rubra), Black Greasewood (Sarcobatus vermiculatus)
Similar Systems
Range
This wetland group occurs throughout the Great Plains Region in Montana, excluding areas in or adjacent to the island mountain ranges.
In Montana, G984 occurs in Level III Ecoregions: 42 (Northwestern Glaciated Plains) and 43 (Northwestern Great Plains).
In Montana, G984 occurs or potentially occurs within these Major Land Resource Areas: 46 - Northern and Central Rocky Mountain Foothills, 52 - Brown Glaciated Plains, 53A - Northern Dark Brown Glaciated Plains, 53B - Central Dark Brown Glaciated Plains, 54 - Rolling Soft Shale Plain, 58A,B,C,D - Northern Rolling High Plains, 60A,B - Pierre Shale Plains.
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
Big Horn, Blaine, Carbon, Carter, Cascade, Chouteau, Custer, Daniels, Dawson, Fallon, Fergus, Garfield, Glacier, Golden Valley, Hill, Judith Basin, Lewis and Clark, Liberty, Mccone, Meagher, Musselshell, Park, Petroleum, Phillips, Pondera, Powder River, Prairie, Richland, Roosevelt, Rosebud, Sheridan, Stillwater, Sweet Grass, Teton, Toole, Treasure, Valley, Wheatland, Wibaux, Yellowstone
Based on 2025 land cover layer.
Spatial Pattern
Small Patch
Environment
These Great Plains sites are distinguished by brackish water caused by strongly saline and alkaline soils. Many of the sites are depressional wetlands though others are found in playas and on stream terraces that are temporarily flooded for part of the growing season. Sites are flat to gently sloping on any aspect. Substrates are moderately saline, often poorly drained, ranging in soil texture from clay and silty clay to silty loam and sandy loam with a clay subsoil (Hanson and Whitman 1938, Jones and Walford 1995). The high salinity of these sites is attributed to excessive evaporation and the accumulation of minerals dissolved in groundwater discharge. Water is prevented from percolating out of the depression due to an impermeable dense clay soil. Salt encrustations can occur on the surface due to slow water movement (Hansen et al, 1995). On the Blackfeet Indian reservation, water samples collected from saline depressions had conductivity values that ranged from 1,550-40,000 uhmos/cm (Lesica 1989). The climate in the Great Plains of Montana is temperate continental, semi-arid to subhumid. Much of the precipitation falls during the winter and spring as snow or rain. Summer precipitation falls as rain during convective thunderstorms.
Vegetation
Sites are sparsely to densely vegetated by herbaceous species tolerant of saline conditions. Some areas may be dominated by halophytic forbs or shrubs. The presence and abundance of various species and communities depends in large part on the local hydrology and salinity. Typical species include Saltgrass (Distichlis spicata), Western Wheatgrass (Pascopyrum smithii), Nuttall's Alkaligrass (Puccinellia nuttalliana), Foxtail Barley (Hordeum jubatum), Alkali Sacaton (Sporobolus airoides), Cordgrass (Spartina spp), Spikerushes (Eleocharis spp), Western Glasswort (Salicornia rubra), and Black Greasewood (Sarcobatus vermiculatus). Sites occur within the matrix of mixed grass prairie primarily in small depressions and flats, though also in playas and on stream terraces that are temporarily flooded for part of the growing season. Total vegetation cover (density and height), species composition, and soil salinity depend on the amount and timing of precipitation and flooding. In playas, growth-inhibiting salt concentrations are diluted when the soil is saturated allowing the growth of less salt-tolerant species. As the saturated soils dry, the salt concentrates until it precipitates on the soil surface (Dodd and Coupland 1966). Vegetation forms zones at some saline sites, where species abundance is stratified by salt tolerance.
Communities within this group in Montana are classified into 4 Alliances and 7 Associations within the National Vegetation Classification. These are relatively well-described vegetation communities and likely cover the range of types present.
National Vegetation Classification
Download the complete NVC hierarchy for Montana
TP1 B08 Palustrine Wetland
TP1.b S70 Emergent Open Wetland
TP1.b3 F139 Inland Salt Marsh
TP1.b3.Na D033 North American Inland Saline Marsh
TP1.b3.Na.1 M077 Great Plains-Eastern Saline Wetland
TP1.b3.Na.1.a G984 Great Plains Saline Wet Meadow and Marsh
A1341 Distichlis spicata - Hordeum jubatum Saline Wet Meadow Alliance
CEGL002273 Distichlis spicata - Hordeum jubatum - Puccinellia nuttalliana - Suaeda calceoliformis Wet Meadow
CEGL002274 Sporobolus airoides Northern Plains Marsh
A1354 Pascopyrum smithii - Distichlis spicata - Hordeum jubatum Wet Grassland Alliance
CEGL001580 Pascopyrum smithii - Distichlis spicata Wet Meadow
CEGL001581 Pascopyrum smithii - Eleocharis spp. Wet Meadow
CEGL001582 Pascopyrum smithii - Hordeum jubatum Wet Meadow
A3905 Sarcobatus vermiculatus Great Plains Wet Shrubland Alliance
CEGL001508 Sarcobatus vermiculatus / Pascopyrum smithii - (Elymus lanceolatus) Shrub Wet Meadow
A4071 Salicornia rubra Wet Meadow Alliance
CEGL001999 Salicornia rubra Salt Flat
*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
These sites and communities are controlled by topographic, soils and hydrological factors. The temporary flooding regime combined with high evaporation rates in these dry climates causes accumulations of soluble salts in the soil. Precipitation and climatic patterns greatly affect the vegetation communities at these sites as precipitation and snowmelt transport salts to the depressions and can dilute the soil solution while temperature and wind influence the rate of evapotranspiration. Increased precipitation and/or runoff can dilute the salt concentration and allow for less salt-tolerant species to occur while increased evapotranspiration increases soil salinity leading to a more brackish habitat type.
Management
Management activities should focus on maintaining local hydrological regimes. Activities in adjacent upland sites may also impact these saline wetlands.
Restoration Considerations
In saline depressional wetlands where water has been drained or altered, the original hydrology of the system must be restored. If hydrology is restored, re-growth and re-colonization from the seedbanks and from dormant rhizomatous root systems of common emergent species can occur during periods of flooding. Cattle grazing should be deferred or controlled to allow regrowth, recolonization and resprouting from existing root systems. Annuals such as Western Glasswort (Salicornia rubra) and annual Goosefoots (Chenopodium spp) require periods of inundation and drawdown to initiate germination and to complete their life cycles at the end of the growing season.
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
Amphibians
Original Concept Authors
Cooper, S.V. et al. (2023)
Montana Version Authors
S. Mincemoyer
Version Date
12/5/2024
References
- Literature Cited AboveLegend:
View Online Publication- Dodd, J.D., and R.T. Coupland. 1966. Vegetation of saline areas in Saskatchewan. Ecology 47(6):958-968.
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.- Hanson, H. C., and W. Whitman. 1938. Characteristics of major grassland types in western North Dakota. Ecological Monographs 8:58-114.
- Jones, G. P., and G. M. Walford. 1995. Major riparian vegetation types of eastern Wyoming. Submitted to Wyoming Department of Environmental Quality, Water Quality Division. Wyoming Natural Diversity Database, Laramie, WY. 245 pp.
- Lesica, P. 1989. The vegetation and flora of glaciated prairie potholes on the Blackfeet Indian Reservation, Montana. Unpublished report to Big Sky Field Office, The Nature Conservancy, Helena, MT, 26 pp.
- Web Search Engines for Articles on "Great Plains Saline Wet Meadow & Marsh"
