Active and Stabilized Dune
Provisional State Rank
This ecological system occurs in the intermountain western US and is composed of a mosaic of migrating, anchored, and stabilized dunes. In Montana, it is documented in the Centennial Valley and near Medicine Lake in the northeast part of the state. This system develops in environments subjected to high winds and sand substrates. Inland sand dunes are dynamic systems which contain three different functional stages: The migrating stage, characterized by large areas of active sand with minimal vegetation cover; the anchored stage, which has sparse vegetation cover (10 – 30%) and minimally active surface sands; and the stabilized stage, typified by dunes which lack active sands and have moderate vegetation cover (Hallock et al 2007). Sand dunes are naturally fluctuating systems where species composition is closely related to the processes of sand erosion, migration, and stabilization. Early and mid-seral species occupying these environments are adapted to moving sands and are generally dominated by green rabbitbrush (Chrysothamnus viscidiflorus), rubber rabbitbrush (Ericameria nauseosa), and needle and thread. Basin big sagebrush (Artemisia tridentata ssp. tridentata), mountain big sagebrush (Artemisia tridentata ssp. vaseyana) and three-tip sagebrush (Artemisia tripartita ssp. tripartita) contribute a moderate amount of cover on stabilized dunes and are associated with needle and thread (Hesperostipa comata) or, in more mesic conditions, Idaho fescue (Festuca idahoensis). Periodic drought, grazing, pocket gopher burrowing activity and fire are the main dynamics influencing this system.
Dune (landform), dune (substrate), sand soil texture, aridic, temperate
This system occurs in Intermountain Basins of the western United States including southwestern Montana in the Centennial Valley and northeastern Montana in Roosevelt and Sheridan counties.
Ecological System Distribution
Approximately 75 square kilometers are classified as Active and Stabilized Dune in the 2017 Montana Land Cover layers.
Grid on map is based on USGS 7.5 minute quadrangle map boundaries.
Montana Counties of Occurrence
Beaverhead, Roosevelt, Sheridan
This is a minor system in Montana, found in the Centennial Valley of southwestern Montana and near medicine lake in northeastern Montana. It occurs as a mosaic, with land cover ranging from shifting, bare dunes with little to no vegetation (usually immediately post-disturbance) to anchored and stabilized dunes with sparse to moderate shrub cover in later successional stages. Throughout its North American range, the system develops in areas with sand substrates and high winds. The Centennial occurrence formed following the drying of post-Pleistocene lakes, when sediments were blown out of the lake basins and the remaining sands were distributed to the northeast of these sources.
Across the system’s U.S. range, the typical primary successional sere on sands appears to be as follows: bare sand or sparse herbaceous vegetation on migrating sand; denser herbaceous vegetation or stands of rubber rabbitbrush (Ericameria nauseosa) on anchored or recently stabilized sand; and shrub vegetation of sagebrush (Artemisia species) on longer-stabilized sands. In Montana, early- and mid-seral shrub communities in dunes are dominated by green rabbitbrush (Chrysothamnus viscidiflorus), rubber rabbitbrush, horse brush (Tetradymia cancescens) and needle and thread (Hesperostipa comata). Several plant species of concern occur in the Centennial Valley dunes and are associated with early-successional stages. In areas where the dunes are stabilized, basin big sagebrush (Artemisia tridentata ssp. tridentata) and three-tip sagebrush (Artemisia tripartita ssp. tripartita) contribute a moderate amount of cover and are associated with needle and thread (Hesperostipa comata) or, in more mesic conditions, mountain big sagebrush (Artemisia tridentata ssp. vaseyana) and Idaho fescue (Festuca idahoensis). These dunes bear a resemblance to the St. Anthony dunes in Idaho (Chadwick and Dalke 1965) but are distinct in many respects.
National Vegetation Classification Switch to Full NVC View
Adapted from US National Vegetation Classification
A1046 Sarcobatus vermiculatus Intermountain Wet Shrubland Alliance
A1262 Achnatherum hymenoides - Pseudoroegneria spicata - Muhlenbergia pungens Grassland Alliance
A3179 Purshia tridentata - Artemisia tridentata Mesic Steppe & Shrubland Alliance
A3198 Artemisia tridentata - Mixed Shrub Dry Steppe & Shrubland Alliance
A3398 Pinus ponderosa Southern Rocky Mountain Forest & Woodland Alliance
A3446 Pinus ponderosa / Shrub Understory Central Rocky Mountain Woodland Alliance
A3759 Populus angustifolia Riparian Forest Alliance
A3985 Elymus lanceolatus - Hesperostipa comata - Phacelia hastata Central Rocky Mountain Sand Deposit Grassland Alliance
CEGL001745 Elymus lanceolatus / Phacelia hastata Grassland
A4011 Redfieldia flexuosa - Leymus flavescens - Achnatherum hymenoides Grassland Alliance
CEGL001650 Achnatherum hymenoides / Psoralidium lanceolatum 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
Sand dunes are highly dynamic systems in which sands migrate and vegetation communities shift naturally. Vegetation in these systems is often adapted to regular disturbance regimes and require it to persist. Disturbances by fire, grazing, and burrowing are important processes influencing successional dynamics (Lesica and Cooper 1998). Fire removes dominant shrubs in stabilized areas and maintains pocket gopher habitat, creating bare areas capable of supporting early successional species. In addition, periodic drought influences dune migration rates by reducing anchoring vegetation cover, thereby making way for early seral species (Marin, 2005; Jones 2006; Forman et al., 2006).
Grazing and occasional wildfires are the primary forces affecting this system. Although not widespread in these areas, off-road travel can be detrimental to the sparse vegetation cover and can contribute to dispersal of invasive species. Invasive species are considered to be one of the primary threats to sand dune systems in the intermountain west. Cheatgrass invasion can reach numbers that stop sand movement and alter the crucial fluctuations of the system (Hallock et al 2007).
Management must account for the dynamic nature of active and stabilized dunes. Substrate migration and shifting vegetation occur naturally in this system. Activities that change the amount and composition of vegetation can alter the dynamic process of sand movement and dune migration (Hallock et al 2007).
Fire followed by intensive ungulate grazing may be the only way to restore early seral vegetation that supports plant species and associations of concern in low-lying areas. In stabilized areas of high topographic relief, restoring presettlement fire frequency will maintain pocket gopher habitat and thus promote a high proportion of early seral vegetation (Lesica and Cooper 1998).
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: mtnhp.org/requests
) 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
||CES304.775, Inter-Mountain Basins Active and Stabilized Dune
3160: Inter-Mountain Basins Active and Stabilized Dune
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Chadwick, H.W., and P.D. Dalke. 1965. Plant succession on dune sands in Fremont County, Idaho. Ecology 46(6):765-780.
- Forman, S L, M Spaeth, L Marín, J Pierson, J Gómez, F Bunch, and A Valdez. 2006. "Episodic Late Holocene dune movements on the sand-sheet area, Great Sand Dunes National Park and Preserve, San Luis Valley, Colorado, USA". Quaternary Research. 66 (1): 97.
- Hallock, L. A., R. D. Haugo, and R. Crawford. 2007. Conservation strategy for Washington State inland sand dunes. Washington Natural Heritage Program, Natural Heritage Report 2007-05, prepared for Bureau of Land Management, Spokane, WA. 82 pp.
- Jones GP. 2006. Survey of tall sagebrush vegetation on stabilized sands in the Jack Morrow Hills Coordinated Management Area, BLM Rock Springs Field Office, Wyoming. Laramie, WY: Wyoming Natural Diversity Database; A report prepared for the Bureau of Land Management's Rock Springs Field Office.
- Lesica, P. & S. V. Cooper. 1998. Succession and disturbance in sandhills vegetation: constructing models for managing biological diversity. Conservation Biology 13:293-302.
- Marin, L, S L Forman, A Valdez, and F Bunch. 2005. "Twentieth century dune migration at the Great Sand Dunes National Park and Preserve, Colorado, relation to drought variability". Geomorphology. 70 (1): 163.