Great Plains Wooded Draw and Ravine
Provisional State Rank
* (see reason below)
State Rank Reason
Drought and change in species composition, along with grazing, are the greatest threats
This system is typically associated with highly intermittent or ephemeral streams. It may occur on steep northern slopes or within canyon bottoms where soil moisture and topography produce higher moisture levels than are common throughout most of the area. In some areas of the western Great Plains, in higher elevation draws and ravines, Rocky Mountain juniper (Juniperus scopulorum) can dominate the canopy. Aspen (Populus tremuloides), paper birch (Betula papyrifera), or boxelder maple (Acer negundo) are commonly present in portions of the northwestern Great Plains. In central and eastern Montana, green ash (Fraxinus pennsylvanicus) or chokecherry (Prunus virginiana) are the usual dominants. Douglas hawthorne (Crataegus douglasii) is occasionally seen as a dominant in south-central Montana, especially around the Pryor Mountains. This system is found in ravines formed by ephemeral and intermittent streams, and on toeslopes and north-facing backslopes. Generally, these systems are less than 50 meters (165 feet) wide, although the linear extent may be considerable. Soils are usually deep and loamy. Flooding is very short in duration when it occurs, as water is rapidly channeled downslope.
Forest and Woodland, draw, ravine
This system is found throughout the Northwestern Glaciated Plains and the Northern Great Plains in Montana.
Ecological System Distribution
Approximately 1,982 square kilometers are classified as Great Plains Wooded Draw and Ravine 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, 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
Wooded draws and ravines are best developed under conditions that favor snow entrapment, development of deeper soils, and concentration of moisture. These conditions are typical of ravines formed by ephemeral and intermittent streams and on toeslopes and north-facing backslopes. Uplands are generally mixed grass prairies and shrublands. Generally, these systems are less than 50 meters (165 feet) wide, although the linear extent may be considerable. Soils are usually deep loams. Flooding is very short in duration when it occurs, as water is rapidly channeled downslope.
In Montana, this community is composed mostly of small trees, although larger diameter trees can occur at the foot of the ravine where there is greater available soil moisture. In some areas of the western Great Plains, in higher elevation draws and ravines, Rocky Mountain juniper can dominate the canopy. Aspen, paper birch or boxelder maple are commonly present in portions of the northwestern Great Plains. Throughout central and eastern Montana, green ash or chokecherry are the typical dominants, although Douglas hawthorne is occasionally seen as a dominant in south-central Montana, especially around the Pryor Mountains. Boxelder maple and American elm (Ulmus rubra or Ulmus americana) are often present. In many parts of Montana, particularly in disturbed occurrences, the understory is a dense shrub layer of western snowberry (Symphoricarpos occidentalis). In less disturbed sites, the understory is two-layered, with a shrub layer of chokecherry and other Prunus species, as well as hawthorne species, silverberry (Elaeagnus commutata), current (Ribes species), Woods' rose (Rosa woodsii), and silver buffaloberry (Shepherdia argentea). The lowest layer is dominated by sedges (Carex species) and grasses such as northern reedgrass (Calamagrostis stricta), western wheatgrass (Pascopyrum smithii), bluebunch wheatgrass (Pseudoroegneria spicata), and thickspike wheatgrass (Elymus lanceolatus). Common forbs include American licorice (Glycyrrhiza lepidota), yarrow (Achillea millefolium), meadow rue (Thalictrum dasycarpum), and bedstraw (Galium species). Exotics such as Russian olive (Elaeagnus angustifolia), yellow sweetclover (Meliotus officinalis) and Kentucky bluegrass (Poa pratensis) are often found throughout these systems, especially in agricultural areas.
National Vegetation Classification Switch to Full NVC View
Adapted from US National Vegetation Classification
A0636 Populus deltoides Floodplain Woodland Alliance
CEGL000660 Populus deltoides - Symphoricarpos occidentalis Floodplain Woodland
A0918 Elaeagnus commutata Wet Shrubland Alliance
CEGL001099 Elaeagnus commutata - Pascopyrum smithii Wet Shrubland
A0954 Crataegus douglasii - Crataegus succulenta Shrubland Alliance
CEGL001093 Crataegus douglasii / (Crataegus chrysocarpa) Shrubland
CEGL001097 Crataegus succulenta Shrubland
A3209 Betula papyrifera - Populus tremuloides - Quercus macrocarpa Forest Alliance
A3210 Juniperus scopulorum - Juniperus virginiana Woodland Alliance
CEGL000747 Juniperus scopulorum - Piptatherum micranthum Woodland
A3211 Fraxinus pennsylvanica - Ulmus americana Great Plains Forest Alliance
CEGL000643 Fraxinus pennsylvanica / Ulmus americana - Prunus virginiana Woodland
A3423 Populus deltoides Floodplain Forest Alliance
CEGL000658 Populus deltoides - Fraxinus pennsylvanica Floodplain Forest
A3427 Juniperus osteosperma - Juniperus scopulorum / Grass Understory Central Rocky Mountain Woodland Alliance
CEGL000748 Juniperus scopulorum - Pseudoroegneria spicata Woodland
A3590 Shepherdia argentea Wet Shrubland Alliance
CEGL001128 Shepherdia argentea Wet Shrubland
A3773 Cornus sericea - Dasiphora fruticosa ssp. floribunda - Ribes spp. Wet Shrubland Alliance
CEGL001126 Rosa woodsii Wet Shrubland
CEGL001165 Cornus sericea Rocky Mountain Wet Shrubland
A3797 Pinus ponderosa - Juniperus scopulorum - Abies concolor Riparian Woodland Alliance
CEGL000746 Juniperus scopulorum - Cornus sericea Riparian Woodland
A3798 Populus deltoides ssp. wislizeni - Populus deltoides ssp. monilifera - Salix amygdaloides Riparian Woodland Alliance
CEGL002680 Populus deltoides (ssp. wislizeni, ssp. monilifera) - Pascopyrum smithii Riparian Woodland
A3799 Rhus trilobata - Crataegus rivularis - Forestiera pubescens Shrubland Alliance
CEGL001098 Elaeagnus commutata Wet Shrubland
CEGL001108 Prunus virginiana / (Prunus americana) Wet Shrubland
A3805 Carex nebrascensis - Carex vesicaria - Carex pellita Wet meadow Alliance
CEGL001813 Carex nebrascensis Wet Meadow
A4036 Prunus virginiana - Symphoricarpos occidentalis - Amelanchier alnifolia Great Plains Shrubland Alliance
CEGL001131 Symphoricarpos occidentalis Shrubland
A4131 Fraxinus pennsylvanica - Ulmus americana - Populus deltoides Floodplain Forest Alliance
*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
Fire, wildlife and livestock use, and invasion by non-native species are major disturbances in this system. Both domestic animals and wildlife use this system readily, leading to trampling of vegetation and an increase in shrub and grass domination. Boxelder is highly susceptible to mechanical damage from livestock (Rosario, 1988), and in stands where green ash is dominant, heavy livestock grazing may prevent regeneration, leading to more open stands dominated by exotic perennial grasses (Lesica, 2009). A study in green ash dominated draws in the northern Great Plains found that exclusion of livestock increased tree height and decreased mortality for both green ash and elm (Uresk et al., 2009).
Fire is a secondary influence and may promote regeneration by encouraging sprouting and thinning of stands (Lesica, 2003). Fire return intervals in this system average approximately 30 years, and range from low-severity surface fires to stand-replacing burns (U.S. Department of Agriculture, 2012). Most species in this system are highly susceptible to fire, although green ash and Rocky Mountain juniper may survive low-intensity burns in some cases (Gucker, 2005; Scher, 2002). Despite experiencing high mortality due to fire, species in this system are fire-adapted and recover quickly via root sprouting, as is the case with aspen and green ash, or by prolific seed production and wind dispersal, as is the case with paper birch and boxelder. Most species in this system, however, are capable of utilizing both strategies to varying degrees (Gucker, 2005; Howard, 1996; Uchytil, 1991; Rosario, 1988).
In parts of eastern Montana, non-native species like Russian olive (Elaeagnus angustifolia) have invaded this system altering vegetation composition and changing biogeochemical cycling in streams (Mineau et al., 2011). Russian olive trees are fast-growing and form a dense canopy that prevents the more shade-intolerant native species typical of this system from establishing (Combs, 2010). Additionally, Russian olive exerts a strong competitive effect on native tree species in this system, inhibiting their establishment (Katz and Shafroth, 2003). Non-native grasses also alter species composition within this system, particularly where green ash is dominant, by forming dense sods and preventing seedling recruitment (Lesica, 2009).
Shade and moisture draw livestock into draws and ravines, concentrating use and creating the potential for degradation and the spread of exotic and invasive species. Alternate shade, water, and forage for livestock can reduce pressure on these systems, and maintain them as wildlife habitat. Fire may have mixed effects on this system. In southeastern Montana, burning resulted in increased abundance and size of crown sprouts in green ash-dominated wooded draws, although significantly fewer seedlings were observed in burned sites (Lesica, 2003). Prescribed burning may be beneficial to maintaining this system where regrowth will not be impeded by invasive grasses, intensive ungulate browsing, or where Russian olive has not invaded (Lesica and Marlow, 2011; Lesica, 2009; Katz and Shafroth, 2003).
Restoration of this system may in part require alternate grazing practices to allow for successful recovery. Dominant species such as chokecherry, Douglas hawthorne and elm have extensive root systems and are rated as good to excellent for soil erosion control. Aspen and paper birch are additionally recommended for revegetation and soil stabilization (Howard, 1996; Uchytil, 1991). In some cases, shrubs can be planted in clusters or bands in areas with high soil erosion potential. All other associated understory shrubs within this system - western snowberry, silverberry, gooseberry, Woods' rose, and silver buffaloberry - are rated as good to excellent restoration species, and possess strongly rhizomatous root systems that minimize soil erosion on steep slopes.
In order to promote regeneration in areas where green ash recruitment has been prevented by exotic grasses, Lesica (2009) recommends herbicide treatment followed by seeding. Alternatively, cutting of mature individuals encourages sprouting, which may be more successful than direct seeding. However, intensive browsing by ungulates may limit the success of this approach (Lesica, 2009). In wooded draws where Russian olive has become dominant, the most effective method of restoration employs a combination of chemical and mechanical treatments. Prescribed burning is not recommended as Russian olive readily resprouts post-fire (Katz and Shafroth, 2003). Combs (2010) recommends specific methods for reducing Russian olive where invasion into this system has occurred.
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:
- 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);
- Evaluating structural characteristics and distribution of each ecological system 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 ecological system;
- 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: http://mtnhp.org/requests/default.asp
) 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.
- 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.
- Native Species Commonly Associated with this Ecological System
- Native Species Occasionally Associated with this Ecological System
Original Concept Authors
Montana Version Authors
- Classification and Map Identifiers
Cowardin Wetland Classification:
National Land Cover Dataset:
|Element Global ID
||CES303.680, Western Great Plains Wooded Draw and Ravine
43: Mixed Forest
4328: Western Great Plains Wooded Draw and Ravine
- Literature Cited AboveLegend: View Online Publication
- Combs, J. 2010. Best Management Practices for Montana Biology, Ecology, and Management of Russian Olive (Elaeagnus angustifolia L.) and Saltcedar (Tamarix ramosissima, T. chinensis, and their hybrids). Natural Resource Conservation Service. ftp://ftpfc.sc.egov.usda.gov/MT/www/technical/invasive/Invasive_Species_Tech_Note_MT30.pdf.
- Gucker, C.L. 2005. Fraxinus pennsylvanica. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.
- Howard, J.L. 1996. Populus tremuloides. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.
- Katz, G.L. and P.B. Shafroth. 2003. Biology, ecology and management of Elaeagnus angustifolia L.(Russian olive) in western North America. Wetlands 23(4):763-777.
- Lesica, P. 2009. Can Regeneration of Green Ash (Fraxinus pennsylvanica) be Restored in Declining Woodlands in Eastern Montana?. Rangeland ecology & management 62(6):564-571.
- Lesica, P. and C.B. Marlow. 2011. Values and management of Montana’s green ash draws. MontGuide No. MT201114AG. Montana State University Extension.
- Lesica, Peter. 2003. 'Effects of Wildfire on Recruitment of Fraxinus pennsylvanica in Eastern Montana Woodlands'. American Midland Naturalist. 149 (2): 258-267.
- Mineau, M.M., C.V. Baxter, and A.M. Marcarelli. 2011. A non-native riparian tree (Elaeagnus angustifolia) changes nutrient dynamics in streams. Ecosystems 14(3):353-365.
- Rosario, L.C. 1988. Acer negundo. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.
- Scher, J.S. 2002. Juniperus scopulorum. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.
- U.S. Department of Agriculture, Forest Service, Missoula Fire Sciences Laboratory. 2012. Information from LANDFIRE on Fire Regimes of Western Great Plains Ash-Elm Communities. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture,
- Uchytil, R.J. 1991. Betula papyrifera. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.
- Uresk, D.W., J. Javersak, and D.E. Mergen. 2009. Tree sapling and shrub heights after 25 years of livestock grazing in green ash draws in western North Dakota. In Proceedings of the South Dakota Academy of Science 88:99-108.