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CEGL001252 Encelia farinosa - Ephedra (fasciculata, nevadensis) Shrubland

The U.S. National
Vegetation Classification
Type Concept Sentence:
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Common (Translated Scientific) Name: Brittlebush - (Arizona Joint-fir, Nevada Joint-fir) Shrubland
Colloquial Name:
Hierarchy Level: Association
Type Concept: This shrubland association has been described from the inner gorge of Grand Canyon National Park in northwestern Arizona. Elevation ranges from 610-1340 m. Stands occur on south-facing colluvial slopes below cliffs. Sites are predominately steep to moderate slopes, often talus with frequent rock outcrops. Substrate is shallow, rocky soil derived from limestone, sandstone, shale or igneous parent materials. Stands have a sparse (less than 20% cover), short woody canopy (less than 1 m tall) that is dominated by the xeromorphic evergreen shrubs Encelia farinosa and the xeromorphic evergreen shrubs Ephedra nevadensis and Ephedra viridis. Other common shrubs and dwarf-shrubs may include Acacia greggii, Gutierrezia sarothrae, or Lycium andersonii. The sparse herbaceous layer is composed of scattered forbs such as Galium stellatum, Machaeranthera pinnatifida, Eriogonum inflatum, and the introduced annual grass Bromus rubens. Succulents are common and include Opuntia basilaris, Opuntia erinacea, Opuntia phaeacantha, Echinocereus engelmannii, Echinocactus polycephalus, Ferocactus cylindraceus (= Ferocactus acanthodes), and Agave utahensis. Extent outside the park is not known. This association appears to be restricted to these inner-canyon habitats in the Grand Canyon. Disturbance from rockslides may be important in maintaining this successional type. Shrublands with similar species composition have been reported from California, but survey and classification work are needed to determine if they represent the same association as this.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: No Data Available
Similar NVC Types:
Physiognomy and Structure: No Data Available
Dynamics: No Data Available
Environmental Description: No Data Available
Geographic Range: Assuming this association is restricted to the Grand Canyon, then its range is less than 5000 square km. Occurrence of stands outside the inner gorge of Grand Canyon National Park is unknown.
Nations: US
States/Provinces: AZ, CA?
US Forest Service Ecoregions (1994/1995)
Domain Name:
Division Name:
Province Name: Colorado Plateau Semi-Desert Province
Province Code: 313    Occurrence Status: Confident or certain
Section Name: Mojave Desert Section
Section Code: 322A     Occurrence Status: Confident or certain
Omernik Ecoregions:
Confidence Level: Low
Confidence Level Comments:
Grank: G3
Greasons: This shrubland association occurs extensively in the inner gorge of Grand Canyon National Park, Arizona. Stands are found predominately on colluvial slopes with southern aspects and may be endemic to the park. Disturbance from rockslides may be important in maintaining this successional type. Within the park, stands are protected, however, condition has declined in some stands because of the abundance of Bromus rubens, an introduced annual grass. The extent and status of this vegetation outside the park is not known. More survey work is needed, especially on colluvial slopes in mountainous areas in the Mojave Desert, which may have similar vegetation.
Concept Lineage:
Obsolete Names:
Obsolete Parents:
Synonomy: = Encelia farinosa - Ephedra spp. - Acacia greggii Association (Warren et al. 1982)
= Encelia farinosa-Ephedra nevadensis-Ephedra viridis (Bourgeron and Engelking 1994)
< DRISCOLL FORMATION CODE:III.C.1.a. (Driscoll et al. 1984)
Concept Author(s): K.A. Schulz
Author of Description: K.A. Schulz
Version Date: 26Nov1997
  • 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.
  • Driscoll, R. S., D. L. Merkel, D. L. Radloff, D. E. Snyder, and J. S. Hagihara. 1984. An ecological land classification framework for the United States. Miscellaneous Publication No. 1439. USDA Forest Service, Washington, DC. 56 pp.
  • Kearsley, M. J. C., K. Green, M. Tukman, M. Reid, M. Hall, T. J. Ayers, and K. Christie. 2015. Grand Canyon National Park-Grand Canyon / Parashant National Monument vegetation classification and mapping project. Natural Resource Report NPS/GRCA/NRR--2015/913. National Park Service, Fort Collins, CO. 75 pp. plus appendices.
  • Reid, M. S., and M. E. Hall. 2010. Vegetation classification of Grand Canyon National Park. Draft report submitted to National Park Service, Fort Collins, CO.
  • Warren, P. L., K. L. Reichhardt, D. A. Mouat, B. T. Brown, and R. R. Johnson. 1982. Vegetation of Grand Canyon National Park. Cooperative National Park Resources Studies Unit Technical Report 9. Tucson, AZ. 140 pp.
  • Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.