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CEGL001664 Pseudoroegneria spicata - Bouteloua gracilis Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Bluebunch Wheatgrass - Blue Grama Grassland
Colloquial Name: Bluebunch Wheatgrass - Blue Grama Mixedgrass Prairie
Hierarchy Level: Association
Type Concept: This bluebunch wheatgrass grassland type is found in the western Great Plains and at low elevations in the Front Range of the Rocky Mountains. In Montana stands are found on toeslopes of the foothills and steeper slopes of valley bottoms. Soils are typically moderately deep (40-100 cm), with a variety of parent materials, and neutral in pH. Surface rock varies from 1-46%. In Montana, the vegetation is open (40-60% cover) and dominated by graminoids. Pseudoroegneria spicata shares dominance with Hesperostipa comata. Bouteloua gracilis is always present, but in varying amounts depending on grazing history (increasing with heavy grazing). Associated graminoids include Carex duriuscula, Koeleria macrantha, and Poa secunda. The most constant forbs include Artemisia frigida (sometimes classified as a shrub), Phlox hoodii and Sphaeralcea coccinea. Slightly more productive sites contain Calamagrostis montanensis, Carex filifolia, Heterotheca villosa, and Liatris punctata. Shrub cover is less than 10%. Low-growing shrubs include Gutierrezia sarothrae and Opuntia polyacantha, and taller shrubs may include Ericameria nauseosa.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: The element summary is based almost entirely on Mueggler and Stewart''s (1980) publication. Thilenius et al. (1995) report a Bouteloua gracilis - Agropyron spicatum type in their preliminary list for the Cheyenne River Basin, Wyoming (west of Rochelle Hills Escarpment). If these types are equal, then this association occurs in Wyoming. Distribution in Colorado is uncertain and removed for now until a wider comparison can be completed.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: In Montana, the vegetation is open (40-60% cover) and dominated by graminoids. Pseudoroegneria spicata shares dominance with Hesperostipa comata (= Stipa comata). Bouteloua gracilis is always present, but in varying amounts depending on grazing history (increasing with heavy grazing). Associated graminoids include Carex duriuscula (= Carex stenophylla), Koeleria macrantha, and Poa secunda (= Poa sandbergii). The most constant forbs include Artemisia frigida (sometimes classified as a shrub), Phlox hoodii and Sphaeralcea coccinea. Slightly more productive sites contain Calamagrostis montanensis, Carex filifolia, Heterotheca villosa (= Chrysopsis villosa), and Liatris punctata. Shrub cover is less than 10%. Low-growing shrubs include Gutierrezia sarothrae and Opuntia polyacantha, and taller shrubs may include Ericameria nauseosa (= Chrysothamnus nauseosus) (Mueggler and Stewart 1980).
Dynamics: Fire and grazing are the most probable natural disturbances. Grazing by pronghorn antelope occurs during the growing season, and both mule deer and elk may utilize this type for winter range (Mueggler and Stewart 1980). Under heavy grazing Pseudoroegneria spicata and Liatris punctata, among others, decline in abundance, whereas Artemisia frigida, Bouteloua gracilis, and Gutierrezia sarothrae increase [see fuller list in Mueggler and Stewart (1980)]. Hesperostipa comata may increase initially as Pseudoroegneria spicata declines, but will eventually decline as well. Artemisia tridentata and Chrysothamnus spp., normally incidental shrubs on this type, may increase to a level of dominance under persistent heavy grazing. Invasive species include Bromus arvensis, Bromus tectorum, Centaurea stoebe ssp. micranthos, Cirsium vulgare, Taraxacum officinale, and Tragopogon dubius. This type is more suitable for grazing by cattle and horses than by sheep, and optimal grazing periods appear to be spring and early fall (Mueggler and Stewart 1980).
Environmental Description: In Montana stands are found on toeslopes of the foothills and steeper slopes of valley bottoms. Soils are typically moderately deep (40-100 cm), with a variety of parent materials, and neutral in pH. Surface rock varies from 1-46% (Mueggler and Stewart 1980). Based on studies in southeastern Wyoming, Bouteloua gracilis, a C4 grass, becomes a minor component of the grassland vegetation above 2300 m, whereas Hesperostipa comata, a C3 grass, is present at over 2600 m (Boutton et al. 1980).
Geographic Range: This community is found in eastern Montana, and possibly Wyoming.
Nations: US
States/Provinces: CO, MT, WY?
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.687353
Confidence Level: Low - Poorly Documented
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.Nb Central North American Grassland & Shrubland Division | D023 | 2.B.2.Nb |
| Macrogroup | 2.B.2.Nb.2 Needle-and-Thread - Western Wheatgrass - Plains Rough Fescue Grassland Macrogroup | M051 | 2.B.2.Nb.2 |
| Group | 2.B.2.Nb.2.b Needle-and-Thread - Blue Grama Dry Mixedgrass Prairie Group | G331 | 2.B.2.Nb.2.b |
| Alliance | A4032 Bluebunch Wheatgrass - Western Wheatgrass - Needle-and-Thread Grassland Alliance | A4032 | 2.B.2.Nb.2.b |
| Association | CEGL001664 Bluebunch Wheatgrass - Blue Grama Grassland | CEGL001664 | 2.B.2.Nb.2.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Agropyron spicatum / Bouteloua gracilis habitat type (Mueggler and Stewart 1980)
? Bouteloua gracilis - Agropyron spicatum type (Thilenius et al. 1995)
? Bouteloua gracilis - Agropyron spicatum type (Thilenius et al. 1995)
- Bear Creek Uranium Mine Application. No date. Unpublished report No. 399 prepared for Wyoming Department of Environmental Quality, Land Quality Division, Cheyenne, WY.
- 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.
- Boutton, T. W., A. T. Harrison, and B. N. Smith. 1980. Distribution of biomass of species differing in photosynthetic pathway along an altitudinal transect in southwestern Wyoming grasslands. Oecologia 45:287-298.
- CNHP [Colorado Natural Heritage Program]. 2006-2017. Tracked natural plant communities. Colorado Natural Heritage Program, Colorado State University, Fort Collins. [https://cnhp.colostate.edu/ourdata/trackinglist/plant_communities/]
- Francis, R. E. 1983. Sagebrush-steppe habitat types in northern Colorado: A first approximation. Pages 67-71 in: Proceedings of the Workshop on Southwestern habitat types. USDA Forest Service, Southwestern Region, Albuquerque, NM.
- MTNHP [Montana Natural Heritage Program]. 2002b. List of ecological communities for Montana. Montana Natural Heritage Program, Montana State Library, 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.
- Terwilliger, C., Jr., and J. A. Tiedemann. 1978. Habitat types of the mule deer critical winter range and adjacent steppe region of Middle Park, Colorado. Unpublished report prepared for USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 108 pp.
- Thilenius, J. F., G. R. Brown, and A. L. Medina. 1995. Vegetation on semi-arid rangelands, Cheyenne River Basin, Wyoming. General Technical Report RM-GTR-263. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 60 pp.
- Tiedemann, J. A., R. E. Francis, C. Terwilliger, Jr., and L. H. Carpenter. 1987. Shrub-steppe habitat types of Middle Park, Colorado. Research Paper RM-273. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 20 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.