Great Plains Floodplain Shrubland and Herbland
Global Name:
Great Plains Riverscour Group
Global Rank:
G3
State Rank:
S2S3
(see reason below)
External Links
State Rank Reason
This Group has experienced significant impacts and alteration from hydrologic changes and water use, grazing practices and invasion by non-native species. Little habitat is likely in good condition and function.
General Description
This National Vegetation Classification Group occurs in riparian habitats throughout the Great Plains. These habitats can be found in and along rivers and streams mostly on recently scoured and/or deposited sand, silts and gravels. Sites may occur on deposits within larger streams and rivers or along the banks and edges of all sizes of streams and rivers. Periodic flooding is important for both creating sites where plants typical of the group can establish and for preventing succession to other vegetation types. Sandbar Willow (Salix exigua) is typically the dominant shrub. Conversely, many different native, herbaceous species may occur in these habitats as either community dominants or with Sandbar Willow. Various, non-native and often invasive grasses and forbs are also common in these areas. Vegetation cover is often low or sparse, especially on more recently deposited alluvium or scoured sites.
This group encompasses a portion of the Great Plains Riparian Ecological System.
Diagnostic Characteristics
Riparian & Wetland; Shrubland; Herbland; Floodplains; Great Plains Region
Typical Dominants: Sandbar Willow (Salix exigua)
Similar Systems
Range
In Montana, this group occurs east of the Continental Divide throughout the Great Plains Region potentially along all perennial stream and river drainages.
In Montana, G568 occurs in Level III Ecoregions 42 (Northwestern Glaciated Plains) and 43 (Northwestern Great Plains).
In Montana, G568 occurs within these Major Land Resource Areas: 52 - Brown Glaciated Plains, 53A - Northern Dark Brown Glaciated Plains, 53B - Central Dark Brown Glaciated Plains, 58A,B,C,D - Northern Rolling High Plains, and 60A,B - Pierre Shale Plains.
Spatial Pattern
Small Patch
Environment
These habitats can be found in and along rivers and streams mostly on recently scoured and/or deposited sand, silts and gravels. Sites may occur on deposits within larger streams and rivers or along the banks and edges of all sizes of streams and rivers. Periodic flooding is important for both creating sites where plants typical of the group can establish and for preventing succession to other vegetation types. In undammed or properly functioning systems, periodic flooding of the fluvial and alluvial soils and channel migration will create alluvial bars, depressions and backwaters supporting zones or mosaics of wetland and riparian vegetation, whose composition and structure is sustained, altered and redistributed by hydrology. This group is more common in the western portions of the Great Plains where the water sources are less consistent and scouring flood events followed by a drop in water levels are more frequent.
Vegetation
Sandbar willow (Salix exigua) is typically the dominant shrub. Other willows such as Diamond Willow (Salix eriocephala) or Bebb’s Willow (Salix bebbiana) may also be present. Seedlings of Eastern Cottonwood (Populus deltoides) may also be present at recently established sites. The herbaceous component may be comprised of various native species with non-native species often present as well. Native species such as Sand Dropseed (Sporobolus cryptandrus), Field Sagewort (Artemisia campestris), Jointed Rush (Juncus articulatus), and Knotweeds and Smartweeds (Polygonum spp.) are often present. Non-natives such as Creeping Bentgrass (Agrostis stolonifera), Reed Canarygrass (Phalaris arundinacea), Quackgrass (Elymus repens), Kentucky Bluegrass (Poa pratensis), Canada Thistle (Cirsium arvense), Leafy Spurge (Euphorbia virgata) and White Clover (Trifolium repens) are some of the many introduced species that may be present at these sites. (Friedman et al. 1996).
Dynamic Processes
This habitat is a disturbance induced and maintained type that requires periodic flooding, scour, and deposition events for establishment and maintenance.
Management
Great Plains riparian habitats have been substantially impacted by damming and the development of both groundwater and surface water for irrigation. Unless water management can restore periodic flooding, floodplains and riparian areas may become dominated by late-seral communities, and nutrient cycles may be disrupted without floodwaters depositing organic material (Decker 2007). In addition, management efforts need to target aggressive non-native shrubs like Salt-cedar (Tamarix spp.) and Russian Olive that can drastically alter ecological processes. Salt-cedar is an early successional species with dispersal strategies and habitat requirements similar to native cottonwoods and willows (Lesica and Miles 2004). It can replace the native vegetation communities where natural flow regimes have been altered. Early detection and rapid response are necessary to prevent its spread. Invasive broadleaf weeds and invasive rhizomatous grasses are also problematic in these habitats and often out-compete native species. For leafy spurge, spring grazing by sheep has been an effective control along some rivers, particularly the upper Powder River (Rinella and Hileman 2009).
Restoration Considerations
Restoration efforts concentrating on the restoration of hydrologic processes or simulating large flood events is neccesary for establishing and maintaining these sites. Removing or limiting grazing can help promote the growth and establishment of desireable, native species while preventing the spread of non-native species.
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
Mammals
Birds
Reptiles
Amphibians
Invertebrates
- Other Native Species Occasionally Associated with this Community
Birds
Amphibians
Invertebrates
Original Concept Authors
J. Drake 2015
Montana Version Authors
S. Mincemoyer
Version Date
11/12/2025
References
- Literature Cited AboveLegend:
View Online Publication- Decker, Karin. 2007. Western Great Plains riparian woodland and shrubland ecological system ecological integrity assessment. Ft. Collins, Colo: Colorado State University, Colorado Natural Heritage Program.
- Friedman, Jonathan M., W.R. Osterkamp, and William M. Lewis. 1996. Channel Narrowing and Vegetation Development Following a Great Plains Flood. Ecology. 77(7): 2167-2181.
Lesica, Peter and Scott Miles. 2004. Ecological strategies for managing tamarisk on the C.M. Russell National Wildlife Refuge, Montana, USA. Biological Conservation 119 (2004), pages 535-543.- Rinella, M.J. and B.J. Hileman. 2009. Efficacy of prescribed grazing depends on timing intensity and frequency. Journal of Applied Ecology. 46, pp 796–803
- Web Search Engines for Articles on "Great Plains Riverscour Group"
