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CEGL003300 Achnatherum hymenoides Shrub Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Indian Ricegrass Shrub Grassland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: Stands occur in the southern Colorado Plateau on low to moderately steep slopes at elevations from 1485-2131 m (4869-6991 feet). Landforms are variable and range from hills, mesas, sideslopes, bajadas to stands along drainage channels and in sand deposits. Substrates are typically sandy soils, but textures range from sandy loam to clay loam. There may be low cover of gravel. The vegetation is characterized by a lush perennial herbaceous layer dominated by Achnatherum hymenoides with an open shrub layer. The total shrub cover ranges from 5-20%. The total herbaceous cover ranges from 50-75%. The shrub stratum is typically composed of a mixture of shrub species, although one may dominate. Common shrubs include scattered Atriplex canescens, Ephedra torreyana, Ericameria nauseosa, Eriogonum leptophyllum, Gutierrezia sarothrae, Parryella filifolia, Purshia tridentata, Tetradymia canescens, or Yucca angustissima. The average height for the shrub stratum is 1-2 m. The herbaceous stratum is dominated by the native grass Achnatherum hymenoides; other herbaceous species present may include Pleuraphis jamesii, Poa fendleriana, or Sporobolus airoides. The non-native invasive species Bromus tectorum and Carduus nutans both occur with significant cover.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This broadly defined semi-arid steppe association was considered a placeholder association and is now considered provisional. Some shrub-steppes are characterized by shrub species and others by graminoids, so it is sometimes confusing as to which is characteristic of an association. Indian ricegrass is a widespread species, and so it is likely this association occurs more widely. Continued survey and classification work are needed to fully characterize this association.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: The association is characterized by a lush perennial herbaceous layer dominated by Achnatherum hymenoides with an open shrub layer. The total shrub cover ranges from 5-20%. The total herbaceous cover ranges from 50-75%. The shrub stratum is typically composed of a mixture of shrub species, although one may dominate. Common shrubs include scattered Atriplex canescens, Ephedra torreyana, Ericameria nauseosa, Eriogonum leptophyllum, Gutierrezia sarothrae, Parryella filifolia, Purshia tridentata, Tetradymia canescens, or Yucca angustissima. The average height for the shrub stratum is 1-2 m. The herbaceous stratum is dominated by the native grass Achnatherum hymenoides; other herbaceous species present may include Pleuraphis jamesii, Poa fendleriana, or Sporobolus airoides. The non-native invasive species Bromus tectorum and Carduus nutans (= ssp. macrolepis) both occur with significant cover.
Dynamics: No Data Available
Environmental Description: Stands occur in the southern Colorado Plateau on low to moderately steep slopes at elevations from 1485-2131 m (4869-6991 feet). Landforms are variable and range from hills, mesas, sideslopes, bajadas to stands along drainage channels and in sand deposits. Substrates are typically sandy soils, but textures range from sandy loam to clay loam. There may be low cover of gravel.
Geographic Range: This shrub-steppe association is known from the southern Colorado Plateau of southwestern Colorado and northeastern Arizona.
Nations: US
States/Provinces: AZ, CO
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.683142
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 3 Desert & Semi-Desert Class | C03 | 3 |
| Subclass | 3.B Cool Semi-Desert Scrub & Grassland Subclass | S11 | 3.B |
| Formation | 3.B.1 Cool Semi-Desert Scrub & Grassland Formation | F033 | 3.B.1 |
| Division | 3.B.1.Ne Western North American Cool Semi-Desert Scrub & Grassland Division | D040 | 3.B.1.Ne |
| Macrogroup | 3.B.1.Ne.1 Yellow Rabbitbrush - Blackbrush / Indian Ricegrass Dry Shrubland & Grassland Macrogroup | M171 | 3.B.1.Ne.1 |
| Group | 3.B.1.Ne.1.c James'' Galleta - Indian Ricegrass - Needle-and-Thread Semi-Desert Grassland Group | G311 | 3.B.1.Ne.1.c |
| Alliance | A1262 Indian Ricegrass - Bluebunch Wheatgrass - Sandhill Muhly Grassland Alliance | A1262 | 3.B.1.Ne.1.c |
| Association | CEGL003300 Indian Ricegrass Shrub Grassland | CEGL003300 | 3.B.1.Ne.1.c |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- Thomas, K. A., M. L. McTeague, A. Cully, K. Schulz, and J. M. S. Hutchinson. 2009a. Vegetation classification and distribution mapping report: Petrified Forest National Park. National Resource Technical Report NPS/SCPN/NRTR--2009/273. National Park Service, Fort Collins, CO. 294 pp.
- Thomas, K., M. Hansen and C. Seger. 2003b. Vegetation of Petrified Forest National Park, Part I: Vegetation of Petrified Forest National Park. Southwest Biological Science Center, U.S. Geological Survey unpublished report to Petrified Forest National Park.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.