Print Report

CEGL000749 Juniperus scopulorum / Purshia tridentata Woodland

Type Concept Sentence: No Data Available


Common (Translated Scientific) Name: Rocky Mountain Juniper / Antelope Bitterbrush Woodland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This woodland association has only been reported from north-central Colorado in Rocky Mountain National Park and northern Arapaho-Roosevelt National Forest. Stands are found on xeric, steep (50-100%), typically south- to west-facing slopes (one east aspect reported) between 2150 and 2600 m (7050-8520 feet) elevation. Substrates are well-drained, poorly developed, coarsely textured, thin soils derived from colluvial and residual parent materials of granite, gneiss and schist. The ground surface area has 40-50% cover of bare soil, exposed rock, and boulder outcroppings. The vegetation is characterized by an open to moderately dense tree canopy dominated by Juniperus scopulorum. Pinus ponderosa and Pseudotsuga menziesii may occasionally occur as scattered individuals. Purshia tridentata dominates the short-shrub layer with 15-25% cover. Rhus trilobata, Linanthus pungens, Rubus deliciosus, Artemisia frigida, and Opuntia polyacantha are shrubs that may be present with a cover of less than 2%. If present, Cercocarpus montanus and Artemisia tridentata cover is low (<5%). Forb and graminoid cover is usually higher than for other Juniperus scopulorum-dominated sites. Commonly associated forbs include Heterotheca villosa, Eriogonum umbellatum, Helianthus pumilus, Potentilla fissa, and Artemisia ludoviciana. Common graminoids include Elymus albicans, Carex rossii, Muhlenbergia montana, and Hesperostipa comata. Diagnostic of this Juniperus scopulorum woodland is the Purshia tridentata-dominated shrub layer.

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 woodland association is characterized by an open to moderately dense tree canopy dominated by Juniperus scopulorum (about 600 trees per acre). Pinus ponderosa and Pseudotsuga menziesii may occasionally occur as scattered individuals. Purshia tridentata dominates the shrub canopy with 15-25% cover. Rhus trilobata, Linanthus pungens (= Leptodactylon pungens), Rubus deliciosus, Artemisia frigida, and Opuntia polyacantha are shrubs that may be present with a cover of less than 2%. If present, Cercocarpus montanus and Artemisia tridentata cover is low (<5%). Forb and graminoid cover is usually higher than for other Juniperus scopulorum-dominated sites. Commonly associated forbs include Heterotheca villosa, Eriogonum umbellatum, Helianthus pumilus, Potentilla fissa (= Drymocallis fissa), and Artemisia ludoviciana. Common graminoids include Elymus albicans (= Elymus lanceolatus ssp. albicans), Carex rossii, Muhlenbergia montana, and Hesperostipa comata (= Stipa comata).

Dynamics:  No Data Available

Environmental Description:  This woodland association has only been reported from north-central Colorado in Rocky Mountain National Park and northern Arapaho-Roosevelt National Forest. Stands are found on xeric, steep (50-100%), typically south- to west-facing slopes (one east aspect reported) between 2150 and 2600 m (7050-8520 feet) elevation. Colluvial and residual parent materials of granite, gneiss and schist origins formed into the well-drained, coarsely textured, thin soils. Soils are minimally developed and consist of Entisols (Ustorthents) at lower, drier sites and Mollisols (Haploborolls) at higher, more mesic sites. The ground surface area has 40-50% cover of bare soil, exposed rock, and boulder outcroppings. Stands usually occur within close proximity to ~Purshia tridentata / Hesperostipa comata Shrub Grassland (CEGL001498)$$.

Geographic Range: This juniper woodland association has only been reported from Rocky Mountain National Park and northern Arapaho-Roosevelt National Forest in north-central Colorado, but may extend north into Wyoming.

Nations: US

States/Provinces:  CO, WY?




Confidence Level: Moderate

Confidence Level Comments: No Data Available

Grank: G2

Greasons: No Data Available


Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: = Juniperus scopulorum / Purshia tridentata Habitat Type (Hess 1981)
= Juniperus scopulorum / Purshia tridentata Habitat Type (Hess and Alexander 1986)
= Juniperus scopulorum / Purshia tridentata Habitat Type (Wasser and Hess 1982)
= Juniperus scopulorum / Purshia tridentata Plant Association (Johnston 1987)

Concept Author(s): L. Tasker

Author of Description: L. Tasker and K.A. Schulz

Acknowledgements: No Data Available

Version Date: 06-03-05

  • 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/]
  • 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 R. R. Alexander. 1986. Forest vegetation of the Arapaho and Roosevelt national forests in northcentral Colorado: A habitat type classification. Research Paper RM-266. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 48 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.).
  • WNDD [Wyoming Natural Diversity Database]. No date. Unpublished data on file. Wyoming Natural Diversity Database, University of Wyoming, Laramie, WY.
  • 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.