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CEGL001518 Artemisia arbuscula ssp. arbuscula - Purshia tridentata / Pseudoroegneria spicata - Festuca idahoensis Shrub Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Little Sagebrush - Antelope Bitterbrush / Bluebunch Wheatgrass - Idaho Fescue Shrub Grassland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: Artemisia arbuscula and Purshia tridentata are the dominant shrubs with Chrysothamnus viscidiflorus and Ericameria nauseosa being minor components. This association usually occurs on side and toe slopes on north, northeastern and eastern aspects at elevations from 1370 to 1525 m (4500-5000 feet). Slopes are gently sloping to nearly level, ranging from 0-5%. Bare ground is 50-75% of ground cover. Stones and gravel cover less than 10% of the surface. Soils are moderately well-drained. Pseudoroegneria spicata and Festuca idahoensis are the dominant grasses, with Achnatherum thurberianum, Elymus elymoides, Poa secunda, Koeleria macrantha and the non-native Bromus tectorum commonly found. Important forbs include Astragalus sp., Erigeron sp., and Lomatium triternatum. The Chrysothamnus species and Bromus tectorum increase with grazing intensity. Normally in central Oregon, Purshia tridentata and Artemisia arbuscula would not be growing together since Purshia tridentata requires a considerably deeper and better drained soil than does Artemisia arbuscula. Tests indicate that the two species are growing on distinct microsites. Artemisia arbuscula grows in areas that have a layer restrictive to roots approximately 38.1-50.8 cm (15-20 inches) deep, and Purshia tridentata occurs on sites where this restrictive layer does not occur. The scattered distribution of the two shrubs reflects an underlying distribution of soil condition. Silica has been identified as the major cementing agent that restricts drainage and root penetration on the Artemisia arbuscula sites.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: No Data Available
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: Artemisia arbuscula and Purshia tridentata are the dominant shrubs with Chrysothamnus viscidiflorus and Ericameria nauseosa (= Chrysothamnus nauseosus) being minor components. Pseudoroegneria spicata and Festuca idahoensis are the dominant grasses, with Achnatherum thurberianum, Elymus elymoides, Poa secunda, Koeleria macrantha and the non-native Bromus tectorum commonly found. Important forbs include Astragalus sp., Erigeron sp., and Lomatium triternatum.
Dynamics: The Chrysothamnus species and Bromus tectorum increase with grazing intensity. Normally in central Oregon, Purshia tridentata and Artemisia arbuscula would not be growing together since Purshia tridentata requires a considerably deeper and better drained soil than does Artemisia arbuscula. Tests indicate that the two species are growing on distinct microsites. Artemisia arbuscula grows in areas that have a layer restrictive to roots approximately 38.1-50.8 cm (15-20 inches) deep, and Purshia tridentata occurs on sites where this restrictive layer does not occur. The scattered distribution of the two shrubs reflects an underlying distribution of soil condition. Silica has been identified as the major cementing agent that restricts drainage and root penetration on the Artemisia arbuscula sites.
Environmental Description: This association usually occurs on side and toe slopes on north, northeastern and eastern aspects at elevations from 1370 to 1525 m (4500-5000 feet). Slopes are gently sloping to nearly level, ranging from 0-5%. Bare ground is 50-75% of ground cover. Stones and gravel cover less than 10% of the surface. Soils are moderately well-drained.
Geographic Range: This association is scattered infrequently across its range which is south-central Oregon. It is sporadic because it requires the juxtaposition of two different soil types, one with a silica hardpan and one without.
Nations: US
States/Provinces: NV, OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.689474
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: G2G3
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.2 Little Sagebrush - Black Sagebrush - Scabland Sagebrush Steppe & Shrubland Macrogroup | M170 | 3.B.1.Ne.2 |
| Group | 3.B.1.Ne.2.b Little Sagebrush - Bigelow''s Sagebrush - Black Sagebrush Steppe & Shrubland Group | G308 | 3.B.1.Ne.2.b |
| Alliance | A3219 Little Sagebrush Steppe & Shrubland Alliance | A3219 | 3.B.1.Ne.2.b |
| Association | CEGL001518 Little Sagebrush - Antelope Bitterbrush / Bluebunch Wheatgrass - Idaho Fescue Shrub Grassland | CEGL001518 | 3.B.1.Ne.2.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- 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.
- Dealy, J. E. 1971. Habitat characteristics of the Silver Lake mule deer range. Research Paper PNW-125. USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Portland, OR. 99 pp.
- Kagan, J. S., J. A. Christy, M. P. Murray, and J. A. Titus. 2004. Classification of native vegetation of Oregon. January 2004. Oregon Natural Heritage Information Center, Portland. 52 pp.
- 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.
- Segura-Bustamante, M. 1970. Ecology of bitterbrush (Purshia tridentata (Pursh) DC) in the Silver Lake Deer Winter Range, Oregon. Unpublished dissertation, Oregon State University, Corvallis. 342 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.