Print Report

CEGL001291 Atriplex canescens / Sporobolus airoides Shrubland

Type Concept Sentence: No Data Available


Common (Translated Scientific) Name: Fourwing Saltbush / Alkali Sacaton Shrubland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This shrubland occurs in the northern Chihuahua Desert extending into the Trans-Pecos of Texas, southwestern Great Plains, and Colorado Plateau. Stands are found in washes, floodplains and on alluvial flats, extending up lower slopes of alluvial fans or bajadas. Elevation ranges from 915-2170 m (3000-7100 feet). Sites are level to gently sloping. Substrates are typically moderately deep, alkaline, calcareous, fine-textured soils or calcareous sands. Some areas are subject to periodic inundation from direct precipitation onto the clayey, somewhat impermeable soils, and runoff from surrounding higher elevations and overtopping drainages. Sediment deposition may occur during these events. Cover of bare soil can be high (>50%). The vegetation is characterized by an open to moderately dense (10-50% cover) short-shrub layer dominated by Atriplex canescens with a perennial graminoid layer dominated by Sporobolus airoides. The shrub layer has greater cover than the herbaceous layer, which may include other scattered shrubs and dwarf-shrubs, such as Artemisia filifolia, Atriplex confertifolia, Atriplex obovata, Chrysothamnus viscidiflorus, Ericameria nauseosa, Gutierrezia sarothrae, Isocoma pluriflora, Krascheninnikovia lanata, Lycium spp., Opuntia spp., Prosopis glandulosa, and Sarcobatus vermiculatus. Associated herbaceous species, such as Achnatherum hymenoides, Ambrosia psilostachya, Artemisia campestris, Elymus elymoides, Pascopyrum smithii, Pleuraphis jamesii, Sphaeralcea coccinea, Sporobolus cryptandrus, Sporobolus nealleyi, and Suaeda spp., may be present. Bouteloua gracilis cover is typically minor and inconsistent. Forbs are limited and scattered and trees are accidental or absent. Diagnostic of this Atriplex canescens-dominated shrubland is a Sporobolus airoides-dominated herbaceous layer.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Stands with relatively low cover of Atriplex canescens (10-25%) are included in this association because the shrub density is often variable within stands, but species composition and ecological processes do not change significantly. There are several similar associations that vary according to the abundance of different codominants, especially graminoids. Rangewide review of these types is needed to clarify their extent.

Similar NVC Types: No Data Available
note: No Data Available

Physiognomy and Structure: No Data Available

Floristics: The association is characterized by an open to moderately dense (10-50% cover) short-shrub layer dominated by Atriplex canescens with a perennial graminoid layer dominated by Sporobolus airoides but includes sparse Atriplex canescens - Sporobolus airoides-dominated stands (<10% total vegetation cover). The shrub layer generally has greater cover than the herbaceous layer and may include other scattered shrubs and dwarf-shrubs, such as Artemisia filifolia, Atriplex confertifolia, Atriplex obovata, Chrysothamnus viscidiflorus, Ericameria nauseosa, Gutierrezia sarothrae, Isocoma pluriflora, Krascheninnikovia lanata, Lycium berlandieri, Lycium pallidum, Cylindropuntia imbricata (= Opuntia imbricata), Cylindropuntia leptocaulis (= Opuntia leptocaulis), Opuntia phaeacantha, Prosopis glandulosa, and Sarcobatus vermiculatus. Associated herbaceous species, such as Achnatherum hymenoides, Ambrosia psilostachya, Artemisia campestris, Elymus elymoides, Pascopyrum smithii, Pleuraphis jamesii, Sphaeralcea spp., Sporobolus cryptandrus, Sporobolus nealleyi, and Suaeda spp., may be present. Bouteloua gracilis cover is typically minor and inconsistent (Francis 1986, Shaw et al. 1989, Muldavin et al. 2000b). However, Bouteloua gracilis with Sporobolus cryptandrus is well-represented within Salinas Pueblo Missions National Monument in New Mexico. Introduced species such as Salsola kali, Bromus tectorum, or Marrubium vulgare may be common. Forbs are limited and scattered and trees are accidental or absent.

Dynamics:  Both Atriplex canescens and Sporobolus airoides are widespread species in semi-arid and arid western North America. Both species are able to tolerate moderately high alkalinity or salinity and finer-textured soils with poor drainage, but they are not restricted to these soils and can be found growing on sand (USFS 1937). Most stands occur on sites that, although located in floodplains or valley floors, will flood only rarely. Atriplex canescens has an extensive root system and is very drought-tolerant. It is very palatable and especially valuable winter forage but can be severely damaged by over-utilization (USFS 1937). Sporobolus airoides produces abundant, long-lived seeds that enable it to fully occupy and dominate favorable sites. It is deep-rooted and produces abundant coarse forage that is best utilized during the growing season (USFS 1937).

Environmental Description:  This shrubland occurs on alkaline sites in the northern Chihuahua Desert extending into the Trans-Pecos of Texas, southwestern Great Plains, and Colorado Plateau. Sites are in washes, floodplains and on alluvial flats, extending up lower slopes of alluvial fans or bajadas. Elevation ranges from 915-2170 m (3000-7100 feet). Sites are level to gently sloping (1-5%), and soils are typically moderately deep, alkaline, calcareous, fine-textured soils such as silt loam, loamy clay or clay (Francis 1986, Shaw et al. 1989, Muldavin et al. 2000b), although some sites in active floodplains may be rapidly drained sandy soils. Some areas are subject to periodic inundation from direct precipitation onto the clayey, somewhat impermeable soils, and runoff from surrounding higher elevations and overtopping drainages. Sediment deposition may occur during these events. The ground surface is characterized by large patches of tussock grasses intermixed with exposed soil and litter. Cover of bare soil may be high (>50%) (Francis 1986). Evidence of overland flow and erosion, e.g., gullies, rills, plant pedestalling, is common (Soil Conservation Service n.d.).

Geographic Range: This shrubland occurs in the northern Chihuahua Desert extending into Trans-Pecos Texas, the southwestern Great Plains and Colorado Plateau in Colorado, New Mexico, Arizona, and Utah. It is reported from California and likely also occurs in Nevada and Mexico.

Nations: MX?,US

States/Provinces:  AZ, CA, CO, NM, NV?, TX, UT




Confidence Level: Moderate

Confidence Level Comments: No Data Available

Grank: G5?

Greasons: No Data Available


Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: >< Atriplex canescens - Atriplex confertifolia / Sporobolus airoides Vegetation Type (Dick-Peddie 1993)
>< Atriplex canescens - Sarcobatus vermiculatus / Sporobolus airoides Vegetation Type (Dick-Peddie 1993)
? Atriplex canescens / Sporobolus airoides - Sitanion hystrix Plant Community (Francis 1986)
? Atriplex canescens / Sporobolus airoides Community Type (Muldavin et al. 1994b)
= Atriplex canescens / Sporobolus airoides Plant Association (Baker 1984a)
? Atriplex canescens / Sporobolus airoides Plant Association (Muldavin et al. 1998d)
= Atriplex canescens / Sporobolus airoides Plant Community (Shaw et al. 1989)
= Fourwing Saltbush/Alkali Sacaton PA (Muldavin et al. 2000b) [(Atriplex canescens/Sporobolus airoides; ATRCAN/SPOAIR)]
? Saline Overflow Range Site #37 B (Soil Conservation Service n.d.)
? Salt Flat Range Site #34 B (Soil Conservation Service n.d.)
< Saltbush Series with Great Basin Desert Scrub (Dick-Peddie 1993)

Concept Author(s): W.L. Baker (1984a)

Author of Description: K.A. Schulz, J. Coles, K.S. King and M.E. Hall

Acknowledgements: No Data Available

Version Date: 05-24-10

  • Baker, W. L. 1984a. A preliminary classification of the natural vegetation of Colorado. Great Basin Naturalist 44(4):647-676.
  • 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/]
  • Clark, D., M. Dela Cruz, T. Clark, J. Coles, S. Topp, A. Evenden, A. Wight, G. Wakefield, and J. Von Loh. 2009. Vegetation classification and mapping project report, Capitol Reef National Park. Natural Resource Report NPS/NCPN/NRTR--2009/187. National Park Service, Fort Collins, CO. 882 pp.
  • Coles, J., A. Tendick, G. Manis, A. Wight, G. Wakefield, J. Von Loh, and A. Evenden. 2009a. Vegetation classification and mapping project report, Arches National Park. Natural Resource Technical Report NPS/NCPN/NRTR--2009/253. National Park Service, Fort Collins, CO. 544 pp.
  • Coles, J., M. Hansen, and K. Thomas. 2003. Wupatki National Monument, Arizona, vegetation classification and distribution: A USGS-NPS Vegetation Mapping Program study. Southwest Biological Science Center, U.S. Geological Survey Open-file Report. [in preparation]
  • Diamond, D. D. 1993. Classification of the plant communities of Texas (series level). Unpublished document. Texas Natural Heritage Program, Austin. 25 pp.
  • Dick-Peddie, W. A. 1993. New Mexico vegetation: Past, present, and future. University of New Mexico Press, Albuquerque. 244 pp.
  • Donart, G. B., D. Sylvester, and W. Hickey. 1978a. A vegetation classification system for New Mexico, USA. Pages 488-490 in: Rangeland Congress, Denver, CO, 14-18 August 1978. Society for Range Management, Denver.
  • Francis, R. E. 1986. Phyto-edaphic communities of the Upper Rio Puerco Watershed, New Mexico. Research Paper RM-272. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 73 pp.
  • Hansen, M., J. Coles, K. A. Thomas, D. Cogan, M. Reid, J. Von Loh, and K. Schulz. 2004b. USGS-NPS Vegetation Mapping Program: Wupatki National Monument, Arizona, vegetation classification and distribution. U.S. Geological Survey Technical Report. Southwest Biological Science Center, Flagstaff, AZ. 229 pp.
  • Muldavin, E., G. Shore, K. Taugher, and B. Milne. 1998d. A vegetation map classification and map for the Sevilleta National Wildlife Refuge, New Mexico. Final report submitted to USDI, U.S. Fish and Wildlife Service, Sevilleta National Wildlife Refuge, Socorro, NM, by the New Mexico Natural Heritage Program, University of New Mexico, Albuquerque. 73 pp. + appendices.
  • Muldavin, E., M. P. Moreno, J. Thomson, and P. Mehlhop. 1994b. A vegetation map for White Sands National Monument. Final report prepared for White Sands National Monument: Alamogordo, NM, by New Mexico Natural Heritage Program.
  • Muldavin, E., Y. Chauvin, A. Kennedy, T. Neville, P. Neville, K. Schulz, and M. Reid. 2012a. Vegetation classification and map: Salinas Pueblo Missions National Monument. Natural Resource Technical Report NPS/SCPN/NRTR--2012/553. National Park Service, Fort Collins, CO.
  • Muldavin, E., Y. Chauvin, T. Neville, P. Neville, A. Kennedy, H. Hulse, P. Arbetan, K. Schultz, M. Hall, and M. Reid. 2013c. Vegetation classification and map: El Malpais National Park. Natural Resource Technical Report NPS/SCPN/NRTR--2013/803. National Park Service, Fort Collins, CO. [http://nhnm.unm.edu/vlibrary/pubs_archive/nhnm/nonsensitive/R13MUL01NMUS.pdf]
  • Muldavin, E., Y. Chauvin, and G. Harper. 2000b. The vegetation of White Sands Missile Range, New Mexico: Volume I. Handbook of vegetation communities. Final report to Environmental Directorate, White Sands Missile Range. New Mexico Natural Heritage Program, University of New Mexico, Albuquerque. 195 pp. plus appendices
  • Peterson, E. B. 2008. International Vegetation Classification alliances and associations occurring in Nevada with proposed additions. Nevada Natural Heritage Program, Carson City, NV. 348 pp.
  • Romme, W. H., K. D. Heil, J. M. Porter, and R. Fleming. 1993. Plant communities of Capitol Reef National Park, Utah. USDI National Park Service, Technical Report NPS/NAUCARE/NRTER-93/02. Cooperative Park Studies Unit, Northern Arizona University. 37 pp.
  • Salas, D. E., D. Wegner, and C. Bolen. 2010a. Vegetation classification and distribution mapping report: Navajo National Monument. Natural Resource Technical Report NPS/SCPN/NRTR--2010/298. National Park Service, Fort Collins, CO. 160 pp.
  • Shaw, R. B., S. L. Anderson, K. A. Schultz, and V. E. Diersing. 1989. Plant communities, ecological checklist, and species list for the U.S. Army Pinon Canyon Maneuver Site, Colorado. Colorado State University, Department of Range Science, Science Series No. 37, Fort Collins. 71 pp.
  • Soil Conservation Service. No date. Range site descriptions of vegetation in Colorado. Unpublished report series MLRA dating from 1975 to 1989. Soil Conservation Service, Colorado Field Office, Denver.
  • Tendick, A., J. Coles, K. Decker, M. Hall, J. Von Loh, T. Belote, A. Wight, G. Wakefield, and A. Evenden. 2012. Vegetation classification and mapping project report, Canyonlands National Park. Natural Resource Technical Report NPS/NCPN/NRTR--2012/577. National Park Service, Fort Collins, CO.
  • USFS [U.S. Forest Service]. 1937. Range plant handbook. Dover Publications Inc., New York. 816 pp.
  • Vest, E. D. 1962a. Biotic communities in the Great Salt Lake Desert. Institute of Environmental Biological Research, Ecology and Epizoology Series 73. Division of Biological Science, University of Utah. 122 pp.
  • Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.