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CEGL001719 Juniperus occidentalis / Artemisia tridentata / Carex filifolia Wooded Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Western Juniper / Big Sagebrush / Threadleaf Sedge Wooded Grassland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: The range of this association is limited, restricted to a small area in and around Horse Ridge Natural Research Area southeast of Bend, in the High Lava Plains section of the Columbia Plateau ecoregion. Juniperus occidentalis is the dominant tree in this old-growth, relatively open woodland. There is a shrub-steppe type understory which is dominated by Artemisia tridentata ssp. wyomingensis with Purshia tridentata as an occasional associate. Grasses dominate the forb layer, with Carex filifolia composing more than half of this cover. Other common associates include Pseudoroegneria spicata, Festuca idahoensis, Koeleria macrantha, Elymus elymoides, Eriogonum microthecum, and Tetradymia canescens. Areas in good condition have high cover of mosses, especially under the Juniperus occidentalis trees. Elevation ranges from 1250-1430 m. The community is located on a broad ridgetop to plateau of rolling topography, although most occurrences are on north-facing slopes. Most precipitation occurs as snow, summers are warm and dry with 1-4 months without rain. Soils are sandy-textured and developed in 30-60 cm of aerially deposited pumice over well-cracked Columbia basalt bedrock.
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: This is a wooded grassland (savanna) association, with a moderately sparse tree layer and a sparse shrub layer. The tree layer consists of an open canopy of the needle-leaved evergreen Juniperus occidentalis, with cover between 10% and 25%. Seedlings and saplings are present. The shrub layer is dominated by the microphyllous evergreen Artemisia tridentata, with occasional associated species such as Purshia tridentata, Tetradymia glabrata and Chrysothamnus viscidiflorus. Total shrub cover is less than 20%. The herbaceous layer is dominated by the perennial sedge Carex filifolia and the bunchgrass Festuca idahoensis. Other perennial grasses commonly present include Pseudoroegneria spicata, Elymus elymoides, Koeleria macrantha, and Achnatherum thurberianum (= Stipa thurberiana). Common perennial forbs include Packera cana (= Senecio canus), Erigeron filifolius, Astragalus curvicarpus, and the suffrutescent Eriogonum umbellatum. The annual forbs Collinsia parviflora and Leptosiphon septentrionalis (= Linanthus septentrionalis) are also commonly present. Total herbaceous cover is greater than 25%, but the average is not known.
Dynamics: No Data Available
Environmental Description: This association occurs within the western juniper zone of central Oregon, which is the most xeric of the tree-dominated regions of the Pacific Northwest. Average annual precipitation in this region is from 20-33 cm (8-13 inches), with most occurring as snow during the cool winter. Summers are hot and dry. The association occurs from 1250-1430 m (4100-4700 feet) elevation on the rolling topography of a ridge which rises above the surrounding plateau. Because of its higher elevation, this ridge receives slightly higher annual and summer precipitation than other areas within the western juniper zone. Columbia River basalts underlie the region. Soils are derived from 30-60 cm (12-24 inches) of aerially deposited pumice over well-cracked basalt bedrock. Textures are sandy loams, organic matter is low, and lower portions of the profiles often have white calcareous or siliceous deposits. The soil surface is bare of litter and is covered by fine pumice gravel.
Geographic Range: The range of this association is limited, restricted to a small area in and around Horse Ridge Natural Research Area southeast of Bend, in the High Lava Plains section of the Columbia Plateau ecoregion.
Nations: US
States/Provinces: OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.689402
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: G1
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 1 Forest & Woodland Class | C01 | 1 |
| Subclass | 1.B Temperate & Boreal Forest & Woodland Subclass | S15 | 1.B |
| Formation | 1.B.2 Cool Temperate Forest & Woodland Formation | F008 | 1.B.2 |
| Division | 1.B.2.Nc Western North American Pinyon - Juniper Woodland & Scrub Division | D010 | 1.B.2.Nc |
| Macrogroup | 1.B.2.Nc.1 Singleleaf Pinyon - Utah Juniper - Western Juniper Intermountain Woodland Macrogroup | M896 | 1.B.2.Nc.1 |
| Group | 1.B.2.Nc.1.b Western Juniper Open Woodland Group | G248 | 1.B.2.Nc.1.b |
| Alliance | A3500 Western Juniper Grassy Open Woodland Alliance | A3500 | 1.B.2.Nc.1.b |
| Association | CEGL001719 Western Juniper / Big Sagebrush / Threadleaf Sedge Wooded Grassland | CEGL001719 | 1.B.2.Nc.1.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.
- Franklin, J. F., F. C. Hall, C. T. Dyrness, and C. Maser. 1972. Federal Research Natural Areas in Oregon and Washington: A guidebook for scientists and educators. USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Portland, OR.
- Franklin, J. F., and C. T. Dyrness. 1973. Natural vegetation of Oregon and Washington. General Technical Report PNW-8. USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Portland, OR. 417 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.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.