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CEGL005074 Ambrosia dumosa Dwarf-shrubland

The U.S. National
Vegetation Classification
Type Concept Sentence:
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Common (Translated Scientific) Name: Burrobush Dwarf-shrubland
Colloquial Name:
Hierarchy Level: Association
Type Concept: This white bursage shrubland association occurs in the Mojave Desert of California, as well as northwestern Arizona and southern Nevada. It is currently described from Grand Canyon National Park and Grand Canyon-Parashant National Monument in Arizona. More survey and classification work are needed to fully characterize this type. It primarily occurs on sideslopes and plateaus at 475 to 575 m (1600 to 1875 feet) elevation; it rarely occurs as high as 625 m (2025 feet). This association is typically found on moderately sloping gradients (10-15°), but occasionally occurs on much flatter slopes (0-4°). Soils are rapidly-drained sands or sandy loams that lie on top of limestone or sandstone. Ambrosia dumosa dominates the dwarf-shrub layer and characterizes this vegetation type. Tall shrubs such as Larrea tridentata occasionally occur in a poorly-defined stratum. Opuntia acanthocarpa, Ephedra torreyana, and Encelia farinosa regularly occur in a sparse short-shrub layer. The cactus Opuntia basilaris is commonly found in the dwarf-shrub layer. Bromus rubens and Vulpia octoflora occur occasionally in the sparse graminoid layer. Eriogonum inflatum, Gilia sp., Cryptantha spp., Pectocarya sp., and Descurainia pinnata are common forbs.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: No Data Available
Similar NVC Types:
Ambrosia dumosa - Encelia farinosa Dwarf-shrubland, note: is also dominated by Ambrosia dumosa, has a similar floristic composition, and is typically found on sideslopes, but Encelia farinosa occurs more frequently and with higher cover.
Physiognomy and Structure: No Data Available
Dynamics: No Data Available
Environmental Description: No Data Available
Geographic Range: This shrubland association is currently known from the Mojave Desert of California and Nevada, and Grand Canyon National Park and Grand Canyon-Parashant National Monument in Arizona. More survey work is needed to fully document its global range.
Nations: US
States/Provinces: AZ, CA, 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: = Ambrosia dumosa (Sawyer et al. 2009) [33.060.02]
= Ambrosia dumosa Association (Evens et al. 2014)
= Ambrosia dumosa Dwarf-shrubland (Reid and Hall 2010)
= Ambrosia dumosa Dwarf-shrubland (Evens and Hartman 2007)
= Ambrosia dumosa Shrubland Association (Evens et al. 2012)
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., D. Roach-McIntosh, and D. Stout. 2012. Vegetation descriptions for Joshua Tree National Park. Unpublished report submitted to USDI, National Park Service, Mojave Desert Inventory and Monitoring Network. California Native Plant Society, 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.