Invalid Unit Specified
CEGL005136 Larrea tridentata - Ambrosia dumosa - Fouquieria splendens Shrubland

The U.S. National
Vegetation Classification
Type Concept Sentence:
Collapse All::Expand All
Common (Translated Scientific) Name: Creosotebush - Burrobush - Ocotillo Shrubland
Colloquial Name:
Hierarchy Level: Association
Type Concept: This creosotebush shrubland association occurs in Arizona and Nevada. It is currently described from Grand Canyon National Park in Arizona. More survey and classification work are needed to fully characterize this type. It typically occurs on sideslopes, terraces, and plateaus at 500 to 600 m (1650-1950 feet) elevation, but can be found as low as 425 m (1400 feet). It is primarily found on fairly gentle gradients (2-10°), but also occasionally occurs on steeper slopes (20°). Soils are rapidly-drained silty loams that typically lie above limestone bedrock. Vegetation is characterized by the codominance of the tall shrubs Larrea tridentata and Fouquieria splendens, and the dwarf-shrub Ambrosia dumosa. Ephedra fasciculata frequently occurs in a relatively weak short-shrub layer, while Psorothamnus sp., Opuntia acanthocarpa, and Encelia farinosa also occur occasionally. The dwarf-shrub layer invariably includes the cactus Opuntia basilaris. Few graminoids occur, but Dasyochloa pulchella does appear fairly consistently. Cryptantha spp., Dichelostemma capitatum, and Phacelia sp. are the most frequent forbs. Eriogonum inflatum and Gilia sp. also sporadically occur in this layer.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: No Data Available
Similar NVC Types:
Larrea tridentata - Encelia farinosa - Fouquieria splendens Shrubland, note: is also codominated by Larrea tridentata and Fouquieria splendens and supports Ambrosia dumosa, Ephedra fasciculata, and Encelia farinosa; however, Encelia farinosa is codominant and Ambrosia dumosa occurs much less frequently.
Physiognomy and Structure: No Data Available
Dynamics: No Data Available
Environmental Description: No Data Available
Geographic Range: This shrubland association is currently known from Lake Mead National Recreation Area and Grand Canyon National Park in northern Arizona and southern Nevada. More survey work is needed to fully document its global range.
Nations: US
States/Provinces: AZ, NV
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 - Poorly Documented
Confidence Level Comments:
Grank: GNR
Concept Lineage:
Obsolete Names:
Obsolete Parents:
Synonomy: = Larrea tridentata - Ambrosia dumosa - Fouquieria splendens (Sawyer et al. 2009) [33.140.44]
= Larrea tridentata - Ambrosia dumosa - Fouquieria splendens Shrubland (Evens and Hartman 2007)
= Larrea tridentata - Ambrosia dumosa - Fouquieria splendens Shrubland (Reid and Hall 2010)
= Larrea tridentata-Ambrosia dumosa-Fouquieria splendens Association (Evens et al. 2014)
Concept Author(s): M.S. Reid and M.E. Hall (2010)
Author of Description: R. Meszaros
Version Date: 06Jan2017
  • Evens, J. M., and S. Hartman. 2007. Vegetation survey and classification for the Northern and Eastern Colorado Desert Coordinated Management Plan (NECO). CNPS Vegetation Program, Sacramento, CA.
  • Evens, J. M., K. Sikes, D. Hastings, and J. Ratchford. 2014. Vegetation alliance descriptions for Lake Mead National Recreation Area, Death Valley National Park and Mojave National Preserve. Unpublished report submitted to USDI National Park Service, Mojave Desert Network Inventory and Monitoring Program. California Native Plant Society, Sacramento, CA. []
  • 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.
  • Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.
  • Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.