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CEGL001497 Purshia tridentata / Pseudoroegneria spicata - Leymus cinereus Shrub Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Antelope Bitterbrush / Bluebunch Wheatgrass - Basin Wildrye Shrub Grassland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This association is reported from sites located on recent, relatively unweathered mafic lava flows of the Great Rift System, within the Snake River Basalt ecoregional section. The plant association occurs in a semi-arid climatic region, on relatively recent mafic volcanic flow substrates. The area has an average annual precipitation of 17 inches, with a peak in winter. Most precipitation occurs as snow. A secondary peak occurs in May. Temperatures are typically hot in summer and cold in winter. The association occurs on slopes of medium-aged and older cinder cones. Sufficient weathering has occurred on these sites so that soil water-holding capacity is great enough to support Purshia tridentata. By comparison, adjacent younger cinder deposits are occupied by ~Eriogonum ovalifolium var. depressum Dwarf-shrubland (CEGL001401)$$. Purshia tridentata forms a low and relatively open layer in this shrub herbaceous type. Cover varies from 15-25%. Several other shrub species are commonly present as scattered individuals, including the deciduous Symphoricarpos oreophilus and Ribes cereum, and the evergreen Ericameria nauseosa, Artemisia tridentata ssp. vaseyana, and Eriogonum heracleoides. Total shrub cover rarely exceeds 30%. The perennial bunchgrass Leymus cinereus dominates the visual aspect of the herbaceous layer, with a growth form of large clumps up to 1 m across. The smaller bunchgrass Pseudoroegneria spicata occurs in higher densities than Leymus cinereus in many areas of this vegetation type. Other grasses usually present include Elymus elymoides, Achnatherum thurberianum, and Poa secunda. The perennial forb Pteryxia terebinthina forms a relatively dense understory, especially where grass density is lower. Other common forbs include Balsamorhiza sagittata, Arabis holboellii, Delphinium andersonii, Lithospermum ruderale, Phacelia hastata, and the suffrutescent species Eriogonum umbellatum and Eriogonum ovalifolium. Total cover of the herbaceous layer is not available, but may be as high as 50%.
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: The broad-leaved deciduous shrub Purshia tridentata forms a low and relatively open layer in this shrub grassland. Cover varies from 15-25%. Several other broad-leaved shrubs are commonly present as scattered individuals, including the deciduous Symphoricarpos oreophilus and Ribes cereum, and the evergreen Ericameria nauseosa (= Chrysothamnus nauseosus), Artemisia tridentata ssp. vaseyana, and Eriogonum heracleoides. Total shrub cover rarely exceeds 30%. The perennial bunchgrass Leymus cinereus dominates the visual aspect of the herbaceous layer, with a growth form of large clumps up to 1 m across. The smaller bunchgrass Pseudoroegneria spicata occurs in higher densities than Leymus in many areas of this vegetation type. Other grasses usually present include Elymus elymoides, Achnatherum thurberianum (= Stipa thurberiana), and Poa secunda. The perennial forb Pteryxia terebinthina forms a relatively dense understory, especially where grass density is lower. Other common forbs include Balsamorhiza sagittata, Arabis holboellii, Delphinium andersonii, Lithospermum ruderale, Phacelia hastata, and the suffrutescents Eriogonum umbellatum and Eriogonum ovalifolium. Total cover of the herbaceous layer is not available, but may be as high as 50%.
Dynamics: No Data Available
Environmental Description: This association occurs in a semi-arid region of relatively recent "plains" volcanic activity. Elevations of the region range from 1490 to 2350 m (4880-7700 feet). The area has an average annual precipitation of 43 cm (17 inches), with a peak in winter during which most precipitation falls as snow. A secondary peak occurs in May. Temperatures are typically hot in summer and cold in winter. This association occurs on slopes of medium-aged and older cinder cones. The weathering of these cinder deposits has proceeded far enough that water-holding capacity is increased over younger cinder deposits which are dominated by Eriogonum ovalifolium. The elevation of the occurrence at Craters of the Moon National Monument is 1770 m (5800 feet). No other information is available.
Geographic Range: The plant association is known only to occur on medium-aged and older cinder cones of the Great Rift System, within the Snake River Basalts ecoregional section.
Nations: US
States/Provinces: ID
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.685323
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G1?
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.3 Big Sagebrush - Threetip Sagebrush - Antelope Bitterbrush Steppe & Shrubland Macrogroup | M169 | 3.B.1.Ne.3 |
| Group | 3.B.1.Ne.3.b Basin Big Sagebrush - Threetip Sagebrush - Antelope Bitterbrush Big Sagebrush Steppe & Shrubland Group | G302 | 3.B.1.Ne.3.b |
| Alliance | A3179 Antelope Bitterbrush - Big Sagebrush Mesic Steppe & Shrubland Alliance | A3179 | 3.B.1.Ne.3.b |
| Association | CEGL001497 Antelope Bitterbrush / Bluebunch Wheatgrass - Basin Wildrye Shrub Grassland | CEGL001497 | 3.B.1.Ne.3.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Purshia tridentata / Agropyron spicatum - Elymus cinereus (Day 1985)
= Antelope Bitterbrush / Great Basin Wildrye Vegetation Type (Day and Wright 1985)
= Antelope Bitterbrush / Great Basin Wildrye Vegetation Type (Day and Wright 1985)
- 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.
- 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.
- Day, T. A. 1985. Plant association and soil factors in primary succession on cinder cones in Idaho. Unpublished thesis, University of Idaho, Moscow. 62 pp.
- Day, T. A., and R. G. Wright. 1985. The vegetation types of Craters of the Moon National Monument. Forestry, Wildlife, and Range Experiment Station Bulletin No. 38. University of Idaho, Moscow. 6 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.