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CEGL005470 Achnatherum thurberianum - Bromus tectorum Ruderal Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Thurber''s Needlegrass - Cheatgrass Ruderal Grassland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This herbaceous vegetation association is dominated by Achnatherum thurberianum, a native perennial bunchgrass. Bromus tectorum, an introduced annual grass, is always present and may codominate. Total vegetation cover ranges from 10 to 70%. Shrubs may occur sporadically with low densities. Artemisia tridentata ssp. wyomingensis, Chrysothamnus viscidiflorus, and Purshia tridentata are the most constant native shrubs in this association. In addition to Achnatherum thurberianum, Pseudoroegneria spicata and Pascopyrum smithii are the most frequently occurring and abundant native grasses in this community type. Several native perennial and annual forb species may also occur with sparse cover and variable species composition across stands of this vegetation type. Non-native forb species are often common, but again, species composition is variable. This association occurs on flat to steeply sloping upland sites. Sites with little slope tend to have deeper soils while those with steeper slopes have shallow to moderately deep soils. Soil texture is loam, sandy loam, or clay loam, and may be highly variable from one stand to another. This association often occurs on or near sites that have been disturbed.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This plant community description is based on data from Craters of the Moon (Bell et al. 2009) and on related plant communities that have been previously described. The description provided herein may vary slightly from similar plant communities found elsewhere due to the local scale at which data were collected. Additional global information will be added as it becomes available.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: No Data Available
Dynamics: The unique life history characteristics of Bromus tectorum and the altered ecological process associated with this species have promoted the spread of it and other exotic annual bromes at the expense of sagebrush shrublands in large parts of the western U.S. Consequently, this species tends to codominate primarily on sites that have been disturbed.
Environmental Description: No Data Available
Geographic Range: The distribution of this association is restricted to sites within the range of Achnatherum thurberianum, primarily in the Owyhee Uplands ecoregional section in southwestern Idaho, southeastern Oregon, and northern Nevada. The range of this vegetation type also coincides with the invasion of Bromus tectorum, often on or in close proximity to sites that have been disturbed.
Nations: US
States/Provinces: ID, NV, OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.947903
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: GNA
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 | CEGL005470 Thurber''s Needlegrass - Cheatgrass Ruderal Grassland | CEGL005470 | 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: = Needlegrass - Cheatgrass Semi-natural Herbaceous Vegetation (Achnatherum thurberianum - Bromus tectorum Semi-natural Herbaceous Vegetation) (Bell et al. 2009)
- Bell, J., D. Cogan, J. Erixson, and J. Von Loh. 2009. Vegetation inventory project report, Craters of the Moon National Monument and Preserve. Natural Resource Technical Report NPS/UCBN/NRTR-2009/277. National Park Service, Fort Collins, CO. 358 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.