Print Report
CEGL001057 Purshia tridentata / Muhlenbergia montana Shrubland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Antelope Bitterbrush / Mountain Muhly Shrubland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This association generally occurs on the eastern slope of the Front Range in northern Colorado at elevations from 2135 to 2730 m (7000-8960 feet). Stands occur on steep, rocky, south-facing slopes. Substrates are rocky, well-drained, poorly developed sandy or loam soils. The vegetation is characterized by a short-shrub layer dominated by Purshia tridentata with Ribes cereum and Artemisia frigida often abundant. Other shrubs may occur in low abundance, such as Prunus virginiana and Rubus deliciosus. The herbaceous layer is dominated by Muhlenbergia montana and sometimes codominated by Hesperostipa comata. Numerous other graminoids and forbs are present in minor amounts. The association often occurs in rocky openings in Pinus ponderosa or Pinus contorta forests.
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 association has a shrub layer dominated by broad-leaved deciduous Purshia tridentata, which averages from 25-40% cover. Artemisia frigida and Ribes cereum are usually present with up to 30% cover. Few other shrub species occur with consistency; however, Arctostaphylos uva-ursi, Artemisia tridentata ssp. vaseyana, Ceanothus fendleri, Chrysothamnus viscidiflorus, Juniperus communis, and Prunus virginiana are sometimes present. The herbaceous layer is dominated by perennial graminoids, with Muhlenbergia montana the most abundant, averaging 12-22% cover. Hesperostipa comata sometimes codominates. Total graminoid cover is about 25%. Other graminoids may include Carex geophila, Carex geyeri, Bromus porteri, Elymus albicans, Leucopoa kingii (= Festuca kingii), Koeleria macrantha, and Muhlenbergia filiculmis. The forb component is relatively diverse, often with 25 species, but not abundant, averaging <15% cover. Important forbs include Achillea millefolium, Antennaria sp., Artemisia ludoviciana, Astragalus sp., Chenopodium leptophyllum, Cryptantha virgata, Erigeron spp., Eriogonum umbellatum, Geranium caespitosum, Harbouria trachypleura, Helianthus pumilus, Heterotheca villosa, Phacelia heterophylla, Potentilla fissa, Penstemon virens, and Symphyotrichum falcatum. Introduced grasses Bromus inermis and Poa pratensis are frequently present.
Dynamics: No Data Available
Environmental Description: This type 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 found are exposed, steep (45-60% slope) mountain slopes with southerly aspects on the eastern slopes of the Front Range, from 2135 to 2730 m (7000-8960 feet) elevation. These sites are typically too xeric to support extensions of the surrounding coniferous forests. Parent materials are colluvial and residual metamorphic rocks which have developed into soils classified as Entisols. These soils are poorly developed and rocky, with loamy and sandy textures, and shallow A horizons over rocky C horizons. The soil surface is also moderately rocky.
Geographic Range: This association is only known from the eastern slope of the Front Range in Larimer and Boulder counties, Colorado.
Nations: US
States/Provinces: CO
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.684966
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G2
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 | CEGL001057 Antelope Bitterbrush / Mountain Muhly Shrubland | CEGL001057 | 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 - Ribes cereum / Muhlenbergia montana Habitat Type (Hess 1981)
= Purshia tridentata / Muhlenbergia montana Habitat Type (Buttery 1955)
= Purshia tridentata / Muhlenbergia montana Habitat Type (Wasser and Hess 1982)
= Purshia tridentata / Muhlenbergia montana Plant Association (Johnston 1987)
= Area F - Purshia (Roughton 1972)
= Kelly Flats Bitterbrush - Area F (Roughton 1966)
= Purshia tridentata / Muhlenbergia montana Habitat Type (Buttery 1955)
= Purshia tridentata / Muhlenbergia montana Habitat Type (Wasser and Hess 1982)
= Purshia tridentata / Muhlenbergia montana Plant Association (Johnston 1987)
= Area F - Purshia (Roughton 1972)
= Kelly Flats Bitterbrush - Area F (Roughton 1966)
- 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.
- Buttery, R. F. 1955. Range conditions and trends resulting from winter concentrations of elk in Rocky Mountain National Park, Colorado. Unpublished thesis. Colorado Agricultural and Mechanical College, Fort Collins. 117 pp.
- 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/]
- 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.
- 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.
- Marr, J. W., D. M. Armstrong, H. Chronic, J. Chronic, R. W. Pennak, W. A. Weber, R. E. Marr, D. Steward, and J. C. Meyer. 1980. Natural landmarks of the southern Rocky Mountain region. Unpublished report prepared for USDI Heritage Conservation and Recreation Service, Denver, CO, by Thorne Ecological Institute, Boulder, CO. 736 pp.
- Roughton, R. D. 1966. Age structure of browse populations. Unpublished thesis, Colorado State University, Fort Collins. 154 pp.
- Roughton, R. D. 1972. Shrub age structures on a mule deer winter range in Colorado. Ecology 53(4):615-625.
- 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.