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CEGL001055 Purshia tridentata / Artemisia frigida / Hesperostipa comata Shrubland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Antelope Bitterbrush / Prairie Sagewort / Needle-and-Thread Shrubland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This shrubland association is described from north-central Colorado, along the eastern slopes of the northern Front Range, on the Arapaho-Roosevelt National Forest. Best developed examples are in the Cache La Poudre River drainage in a narrowly restricted latitudinal range. Sites where this association is found are steep to very steep (30-55%) mountain slopes with southerly aspects from 1770-2350 m (5800-7700 feet) elevation and are too xeric to support coniferous woodland. Parent materials are colluvium of schist and gneiss origins which have developed into soils classified as Entisols. These soils are poorly developed, coarse-textured and rocky, with loamy and sandy textures. There is typically a shallow A horizon over a cambic B horizon over rocky C horizons. The soil surface is also moderately rocky. The broad-leaved, semi-evergreen shrub Purshia tridentata averages 30% cover in this shrubland association, with heights of 1-2 m. Other shrubs are poorly represented. Artemisia frigida is present in all stands, averaging 4% cover. The herbaceous layer is moderately dense to relatively sparse and dominated by the 0.5-m tall perennial bunchgrass Hesperostipa comata. Other important species present in lesser amounts include perennial grasses Bouteloua gracilis and Elymus albicans, and the perennial forbs Heterotheca villosa, Eriogonum umbellatum, Helianthus pumilus, and Scutellaria brittonii.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This G1G2 shrubland is characterized by a short-shrub layer dominated by Purshia tridentata, with a dwarf-shrub layer dominated by Artemisia frigida and a graminoid layer dominated by Hesperostipa comata. It is currently restricted from the northern Front Range from the St. Vrain River to Poudre River canyons.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: The broad-leaved, semi-evergreen shrub Purshia tridentata averages 30% cover in this shrubland association, with heights of 1-2 m. Other shrubs are poorly represented, but the low Artemisia frigida is present in all stands, averaging 4% cover (Hess 1981). Other taller shrubs occasionally associated with this type include Rhus trilobata, Ribes cereum, and Rubus deliciosus. The herbaceous layer is relatively sparse and dominated by the 0.5-m tall perennial bunchgrass Hesperostipa comata (= Stipa comata), with 15% cover. Other important species present in small amounts include the perennial grasses Bouteloua gracilis and Elymus albicans (= Elymus lanceolatus ssp. albicans), and the perennial forbs Heterotheca villosa, Eriogonum umbellatum, Helianthus pumilus, and Scutellaria brittonii (Hess 1981).
Dynamics: Grazing of livestock is likely to reduce shrub cover and that of herbaceous species as well.
Environmental Description: This association occurs in a mountainous region subject to a continental climate regime, with warm summers and cold winters. Precipitation patterns differ between the east and west sides of the Continental Divide, but the overall difference is warmer and drier winters on the east slope of the Front Range.
Sites where this association is found are steep to very steep (30-55%) mountain slopes with southerly aspects on the eastern slopes of the Front Range, from 1770-2350 m (5800-7700 feet) elevation. These sites are typically too xeric to support coniferous forests. Parent materials are colluvium of schist and gneiss origins which have developed into soils classified as Entisols. These soils are poorly developed, coarse-textured and rocky, with loamy and sandy textures. There is typically a shallow A horizon over a cambic B horizon over rocky C horizons (Hess 1981). The soil surface is also moderately rocky.
Sites where this association is found are steep to very steep (30-55%) mountain slopes with southerly aspects on the eastern slopes of the Front Range, from 1770-2350 m (5800-7700 feet) elevation. These sites are typically too xeric to support coniferous forests. Parent materials are colluvium of schist and gneiss origins which have developed into soils classified as Entisols. These soils are poorly developed, coarse-textured and rocky, with loamy and sandy textures. There is typically a shallow A horizon over a cambic B horizon over rocky C horizons (Hess 1981). The soil surface is also moderately rocky.
Geographic Range: This lower montane shrubland association occurs in north-central Colorado, along the eastern slopes of the northern Front Range in Boulder and Larimer counties.
Nations: US
States/Provinces: CO
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.687443
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G1G2
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.1 Gambel Oak - Alderleaf Mountain-mahogany - Bitterbrush species Southern Rocky Mountain Montane Shrubland Macrogroup | M049 | 2.B.2.Nf.1 |
| Group | 2.B.2.Nf.1.b Alderleaf Mountain-mahogany - Wavyleaf Oak - Skunkbush Sumac Foothill Shrubland Group | G276 | 2.B.2.Nf.1.b |
| Alliance | A3731 Antelope Bitterbrush - Wax Currant Shrubland Alliance | A3731 | 2.B.2.Nf.1.b |
| Association | CEGL001055 Antelope Bitterbrush / Prairie Sagewort / Needle-and-Thread Shrubland | CEGL001055 | 2.B.2.Nf.1.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: >< Purshia tridentata / Stipa comata Habitat Type (Daubenmire 1970)
= Purshia tridentata / Stipa comata Habitat Type (Hess 1981)
= Purshia tridentata / Stipa comata Habitat Type (Wasser and Hess 1982)
< Purshia tridentata / Stipa comata Plant Association (Johnston 1987) [Includes stands from eastern Washington, eastern Idaho and northwestern Colorado.]
= Purshia tridentata / Stipa comata Habitat Type (Hess 1981)
= Purshia tridentata / Stipa comata Habitat Type (Wasser and Hess 1982)
< Purshia tridentata / Stipa comata Plant Association (Johnston 1987) [Includes stands from eastern Washington, eastern Idaho and northwestern Colorado.]
- 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.
- 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/]
- Daubenmire, R. F. 1970. Steppe vegetation of Washington. Washington State University Agricultural Experiment Station Technical Bulletin No. 62. 131 pp.
- Hess, K. 1981. Phyto-edaphic study of habitat types of the Arapaho-Roosevelt National Forest, Colorado. Unpublished dissertation, Colorado State University, Fort Collins. 558 pp.
- Hess, K., and C. H. Wasser. 1982. Grassland, shrubland, and forest habitat types of the White River-Arapaho National Forest. Unpublished final report 53-82 FT-1-19. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 335 pp.
- 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.
- Salas, D., J. Stevens, and K. Schulz. 2005. USGS-NPS Vegetation Mapping Program: Rocky Mountain National Park, Colorado. Technical Memorandum No. 8260-05-02. USDI Bureau of Reclamation, Denver, CO. 161 pp. plus Appendices A-L (733 pp.).
- Wasser, C. H., and K. Hess. 1982. The habitat types of Region II. USDA Forest Service: A synthesis. Final report prepared for USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 140 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.