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CEGL001443 Atriplex gardneri / Monolepis nuttalliana Dwarf-shrubland

Type Concept Sentence: This open dwarf-shrubland occurs on low ridges and toeslopes in badlands in the Big Horn Basin of Montana and Wyoming. Stands typically have a relatively sparse dwarf-shrub canopy (35% mean cover) that is dominated by Atriplex gardneri.

Common (Translated Scientific) Name: Gardner''s Saltbush / Nuttall''s Povertyweed Dwarf-shrubland

Colloquial Name: Great Plains Badlands Gardner''s Saltbush

Hierarchy Level:  Association

Type Concept: This open dwarf-shrubland occurs on low ridges and toeslopes in badlands in the Big Horn Basin of Montana and Wyoming. Elevation ranges from 1500-1600 m. The association is restricted to arid climatic regimes and sites with deep, heavy clay soil derived from shale, clay or bentonite deposits. The soil has extremely low infiltration, and although gently sloping, it is typically eroded. Gravel and salt deposits are often present on the surface. Stands typically have a relatively sparse dwarf-shrub canopy (35% mean cover) that is dominated by Atriplex gardneri. Scattered Sarcobatus vermiculatus and Suaeda moquinii may also be present. Herbaceous cover is dominated by the annual forb Monolepis nuttalliana with 34% mean cover. Other species may include sparse cover of the grasses Hordeum jubatum, Achnatherum hymenoides, scattered forbs such as Platyschkuhria integrifolia, Allium textile, Camissonia scapoidea, Musineon divaricatum, and the cactus Opuntia polyacantha. There are nine other dwarf-shrublands and two shrublands with Atriplex gardneri dominant or codominant in the canopy, but none have herbaceous layers dominated by Monolepis nuttalliana.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: As currently and narrowly defined this association occurs only within the Bighorn Basin Section of Montana, but Atriplex gardneri exists as a dominant on many "badlands" formations, including deeply weathered shale ridges, bentonite outcrops, fine-textured outwash soils and pan spots, throughout Montana and the Intermountain West and into Saskatchewan. It is difficult to compare these sites with the type cited here because the co-indicator is an annual forb.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: Stands typically have a relatively sparse dwarf-shrub canopy (35% mean cover) that is dominated by Atriplex gardneri. Scattered Sarcobatus vermiculatus and Suaeda moquinii (= Suaeda nigra) may also be present. Herbaceous cover is dominated by the annual forb Monolepis nuttalliana with 34% mean cover. Other species may include sparse cover of the grasses Hordeum jubatum, Achnatherum hymenoides (= Oryzopsis hymenoides), scattered forbs such as Platyschkuhria integrifolia, Allium textile, Camissonia scapoidea, Musineon divaricatum, and the cactus Opuntia polyacantha.

Dynamics:  No Data Available
Environmental Description:  Elevation ranges from 1500-1600 m. The association is restricted to arid climatic regimes and sites with deep, heavy clay soil derived from shale, clay or bentonite deposits. The soil has extremely low infiltration, and although gently sloping, it is typically eroded. Gravel and salt deposits are often present on the surface.
Geographic Range: This association occurs only within the Bighorn Basin Section of Montana and possibly in the same section in Wyoming.

Nations: US

States/Provinces:  MT, WY?


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: G3?

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.B Temperate & Boreal Grassland & Shrubland Subclass S18 2.B
Formation 2.B.2 Temperate Grassland & Shrubland Formation F012 2.B.2
Division 2.B.2.Nb Central North American Grassland & Shrubland Division D023 2.B.2.Nb
Macrogroup 2.B.2.Nb.2 Needle-and-Thread - Western Wheatgrass - Plains Rough Fescue Grassland Macrogroup M051 2.B.2.Nb.2
Group 2.B.2.Nb.2.b Needle-and-Thread - Blue Grama Dry Mixedgrass Prairie Group G331 2.B.2.Nb.2.b
Alliance A4381 None A4381 2.B.2.Nb.2.b
Association CEGL001443 Gardner''s Saltbush / Nuttall''s Povertyweed Dwarf-shrubland CEGL001443 2.B.2.Nb.2.b
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Atriplex nuttallii / Monolepis nuttalliana Plant Community (DeVelice and Lesica 1993)
= Atriplex nuttallii / Monolepis nuttalliana Plant Community (Lesica and DeVelice 1992)
Concept Author(s): K.A. Schulz and S.V. Cooper

Author of Description: K.A. Schulz and S.V. Cooper

Acknowledgements: No Data Available

Version Date: 01-16-19
  • 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.
  • DeVelice, R. L., and P. Lesica. 1993. Plant community classification for vegetation on BLM lands, Pryor Mountains, Carbon County, Montana. Unpublished report by Montana Natural Heritage Program, Helena, MT. 78 pp.
  • Lesica, P., and R. L. DeVelice. 1992. Plant communities of the Pryor Mountains. Preliminary report prepared by the Montana Natural Heritage Program, Helena, MT.
  • MTNHP [Montana Natural Heritage Program]. 2002b. List of ecological communities for Montana. Montana Natural Heritage Program, Montana State Library, Helena, MT.
  • Stevens, J. E., D. S. Jones, and K. J. Benner. 2015. Vegetation classification and mapping project report: Bighorn Canyon National Recreation Area. Natural Resource Report NPS/GRYN/NRR--2015/1070. National Park Service, Fort Collins, CO. 350 pp.
  • Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.