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CEGL001679 Pseudoroegneria spicata - Hesperostipa comata Grassland

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Bluebunch Wheatgrass - Needle-and-Thread Grassland

Colloquial Name: Bluebunch Wheatgrass - Needle-and-Thread Mixedgrass Prairie

Hierarchy Level:  Association

Type Concept: This grassland association occurs in the Columbia Basin and Great Basin across north-central Wyoming east to the Bighorn Mountains into the northwestern Great Plains. Stands occur on a variety of sites that include windswept slopes and ridges. Sites range from gentle to steep slopes on all aspects. Bare soil, leaf litter, and gravel cover most of the ground surface. The vegetation is characterized by an open to moderately dense bunchgrass layer codominated by Pseudoroegneria spicata and Hesperostipa comata. The dwarf-shrubs Artemisia frigida and Gutierrezia sarothrae occur with sparse cover. Other graminoids include Bouteloua gracilis, Carex spp., Koeleria macrantha, Leymus cinereus, Poa fendleriana, and Poa secunda. Associated forbs include Astragalus spp., Comandra umbellata, Phlox hoodii, and Sphaeralcea munroana. The exotic annual grass Bromus tectorum is present to abundant on some sites.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: No Data Available

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: This grassland is characterized by an open to moderately dense bunchgrass layer codominated by Pseudoroegneria spicata and Hesperostipa comata. The dwarf-shrubs Artemisia frigida and Gutierrezia sarothrae occur with sparse cover. Occasional shrubs, such as Artemisia tridentata ssp. wyomingensis, Chrysothamnus viscidiflorus, and Ericameria nauseosa, are sometimes present. Other graminoids include Bouteloua gracilis, Carex spp., Koeleria macrantha, Leymus cinereus, Poa fendleriana, and Poa secunda. Associated forbs include Astragalus spp., Comandra umbellata, Phlox hoodii, and Sphaeralcea munroana. The exotic annual grass Bromus tectorum is present to abundant on some sites.

Dynamics:  Pseudoroegneria spicata decreases in abundance with heavy grazing, while Bouteloua gracilis, Koeleria macrantha, Poa fendleriana, and Poa secunda increase (Tweit and Houston 1980). Hesperostipa comata may initially increase, then decreases with heavy grazing (Tweit and Houston 1980). Shrubs and dwarf-shrubs also increase with overgrazing and may eventually dominate (Tweit and Houston 1980). The amount and season of grazing and precipitation also affect relative abundances of grass species over time.
Environmental Description:  This grassland association occurs in the Columbia Basin and Great Basin across north-central Wyoming east to the Bighorn Mountains into the northwestern Great Plains. Elevation can range from approximately 915 to 2440 m (3000-8000 feet). Stands occur on a variety of sites that include windswept slopes and ridges. Sites range from gentle to steep slopes on all aspects. Bare soil, leaf litter, and gravel cover most of the ground surface. Soils are often deep and rocky and derived from limestones and volcanics.
Geographic Range: This grassland association occurs in the Columbia Basin and Great Basin extending east to the Bighorn Mountains to the northwestern Great Plains.

Nations: US

States/Provinces:  MT, NV, OR, UT, WY


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: G4

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.B Temperate & Boreal Grassland & Shrubland Subclass S18 2.B
Formation 2.B.2 Temperate Grassland & Shrubland Formation F012 2.B.2
Division 2.B.2.Nf Western North American Grassland & Shrubland Division D022 2.B.2.Nf
Macrogroup 2.B.2.Nf.2 Saskatoon Serviceberry / Idaho Fescue - Bluebunch Wheatgrass Grassland & Shrubland Macrogroup M048 2.B.2.Nf.2
Group 2.B.2.Nf.2.c Rough Fescue - Idaho Fescue - Bluebunch Wheatgrass Central Rocky Mountain Foothill Grassland Group G273 2.B.2.Nf.2.c
Alliance A3987 Idaho Fescue - Bluebunch Wheatgrass - Sandberg Bluegrass Dry Grassland Alliance A3987 2.B.2.Nf.2.c
Association CEGL001679 Bluebunch Wheatgrass - Needle-and-Thread Grassland CEGL001679 2.B.2.Nf.2.c
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: > Agropyron - Poa Zone, Climatic Climax (Poulton 1955)
= Agropyron spicata / Poa sandbergii Habitat Type, Phase Stipa comata (Tweit and Houston 1980)
= Agropyron spicata / Poa sandbergii Habitat Type, Phase Stipa comata (Mueggler and Stewart 1980)
? Agropyron spicatum / Poa secunda Habitat Type (Daubenmire 1970)
< Elymus spicatus Vegetation Type (Jones and Ogle 2000)
= Roegneria spicata Plant Association (Johnston 1987)
Concept Author(s): Western Ecology Group

Author of Description: K.A. Schulz

Acknowledgements: No Data Available

Version Date: 05-06-08
  • Anderson, W. E. 1956. Some soil-plant relationships in eastern Oregon. Journal of Range Management 9:171-175.
  • Bighorn Coal Mine. No date. Application No. 213-T2, on file at Wyoming Department of Environmental Quality, Land Quality Division, Cheyenne.
  • Bourgeron, P. S., and L. D. Engelking, editors. 1994. A preliminary vegetation classification of the western United States. Unpublished report. The Nature Conservancy, Western Heritage Task Force, Boulder, CO. 175 pp. plus appendix.
  • Cogan, D., J. E. Taylor, and K. Schulz. 2012. Vegetation inventory project: Great Basin National Park. Natural Resource Report NPS/MOJN/NRR--2012/568. National Park Service, Fort Collins, CO. 373 pp.
  • Coles, J., A. Wight, J. Von Loh, K. Schulz, and A. Evenden. 2011. Vegetation classification and mapping project report, Golden Spike National Historic Site. Natural Resource Technical Report NPS/NCPN/NRTR---2011/508. National Park Service, Fort Collins, CO. 252 pp. [http://www.nature.nps.gov/im/units/NCPN]
  • Daubenmire, R. F. 1970. Steppe vegetation of Washington. Washington State University Agricultural Experiment Station Technical Bulletin No. 62. 131 pp.
  • Hyde, R. M. 1964. Vegetation in Sunlight Basin, Park County, Wyoming. Unpublished dissertation, University of Wyoming, Laramie.
  • Johnston, B. C. 1987. Plant associations of Region Two: Potential plant communities of Wyoming, South Dakota, Nebraska, Colorado, and Kansas. R2-ECOL-87-2. USDA Forest Service, Rocky Mountain Region. Lakewood, CO. 429 pp.
  • Jones, G., and S. Ogle. 2000. Characterization abstracts for vegetation types on the Bighorn, Medicine Bow, and Shoshone national forests. Prepared for USDA Forest Service, Region 2 by the Wyoming Natural Diversity Database, University of Wyoming.
  • Kagan, J. S., J. A. Christy, M. P. Murray, and J. A. Titus. 2004. Classification of native vegetation of Oregon. January 2004. Oregon Natural Heritage Information Center, Portland. 52 pp.
  • MTNHP [Montana Natural Heritage Program]. 2002b. List of ecological communities for Montana. Montana Natural Heritage Program, Montana State Library, Helena, MT.
  • MTNHP [Montana Natural Heritage Program]. No date. Unpublished data on file. Montana Natural Heritage Program, Helena, MT.
  • Mueggler, W. F., and W. L. Stewart. 1980. Grassland and shrubland habitat types of western Montana. General Technical Report INT-66. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT. 154 pp.
  • Poulton, C. E. 1955. Ecology of the non-forested vegetation in Umatilla and Morrow counties, Oregon. Unpublished dissertation. State College of Washington, Pullman. 166 pp.
  • Schulz, K. A., and M. E. Hall. 2011. Vegetation inventory project: Great Basin National Park. Unpublished report submitted to USDI National Park Service, Mojave Desert Inventory and Monitoring Network. NatureServe, Western Regional Office, Boulder, CO. 30 pp. plus Appendices A-H.
  • Stevens, J. E., D. S. Jones, and K. J. Benner. 2015. Vegetation classification and mapping project report: Bighorn Canyon National Recreation Area. Natural Resource Report NPS/GRYN/NRR--2015/1070. National Park Service, Fort Collins, CO. 350 pp.
  • Tweit, S., and K. Houston. 1980. Grassland and shrubland habitat types of the Shoshone National Forest. USDA Forest Service, Rocky Mountain Region, Shoshone National Forest.
  • WNDD [Wyoming Natural Diversity Database]. No date. Unpublished data on file. Wyoming Natural Diversity Database, University of Wyoming, Laramie, WY.
  • Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.
  • Williams, C. 1961. Distribution of vegetation in the Wind River Canyon, Wyoming. Wyoming Range Management 150:1-2.