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CEGL000961 Cercocarpus ledifolius / Calamagrostis rubescens Woodland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Curl-leaf Mountain-mahogany / Pinegrass Woodland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This woodland association is found in eastern Oregon and Idaho. Mean annual precipitation is 56 cm, which falls predominantly as heavy snowfall in the winter. Stands are consistently found on north- or northeast-facing slopes between 1750-1920 m elevation. Slopes are moderate, between 10-40%. Soils are moderately deep varying from gravelly to sandy loams overlying fractured Rhyolitic bedrock. The canopy cover of the woodland/tall shrubland type averages 80%, and is dominated by Cercocarpus ledifolius. The only other tree that occurs in this association is an occasional Prunus emarginata. The shrub layer is sparse. Amelanchier alnifolia and Mahonia repens are ubiquitous while Chrysothamnus viscidiflorus, Ericameria nauseosa and Eriogonum heracleoides are occasional associates. Calamagrostis rubescens is the dominant grass in lightly to moderately grazed stands. In areas which have received heavy grazing Festuca idahoensis or Achnatherum lemmonii codominate with the Calamagrostis rubescens. Other graminoids include Elymus elymoides, Elymus glaucus, Elymus caninus, and Carex rossii. The dominant forb in undisturbed stands is Hieracium cynoglossoides. On disturbed sites Viola nuttallii dominates. Common forbs on all sites include Geum triflorum, Agoseris heterophylla, and Achillea millefolium.
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: Percent cover values are not available for most species in this association. Cercocarpus ledifolius, a broad-leaved evergreen species usually considered a shrub, takes on the form of a small tree, up to 7 m tall. It dominates the canopy, with cover averaging 76-83%. Several broad-leaved deciduous shrubs up to 2 m tall occur in most stands, including Amelanchier alnifolia, Prunus emarginata, Ribes cereum, and Mahonia repens. Chrysothamnus viscidiflorus, Ericameria nauseosa (= Chrysothamnus nauseosus) and Eriogonum heracleoides are occasional associates. The herbaceous layer is dominated by a mix of perennial grasses, with Calamagrostis rubescens usually the most abundant. Some stands with slightly more mesic conditions are dominated by Festuca idahoensis. Other abundant and constant species include Achnatherum lemmonii (= Stipa lemmonii), Elymus elymoides (= Sitanion hystrix) and Poa secunda, and the perennial sedge Carex rossii. Several forbs are present in most stands, including the perennials Hieracium scouleri var. albertinum (= Hieracium albertinum), Viola nuttallii, Geum triflorum, and Senecio integerrimus, and the annual Agoseris heterophylla. An orchid, Piperia unalascensis, occurred in half of the stands. Several stands of this association show signs of past overgrazing by livestock, particularly sheep. The introduced forbs Cirsium vulgare and Taraxacum officinale are common to abundant in these stands, and two native species have increased abundance related to grazing, i.e., Achnatherum lemmonii and Viola nuttallii.
Dynamics: Many stands of Cercocarpus ledifolius trees in the Owyhee Uplands were cut for firewood during the late 1800s and into the early 1900s. This has resulted in these stands having a dense, shrubby physiognomy (thickets) rather than a taller tree form. Dealy (1975) reported that this species can reach heights of 15 m in these uplands and considered it a tree.
The presence and/or abundance of several herbaceous species within some stands of this association are indicators of good recovery from past impacts of livestock grazing. These species include Elymus caninus, Poa secunda, Hieracium scouleri var. albertinum, Agoseris heterophylla, and Piperia unalascensis.
The presence and/or abundance of several herbaceous species within some stands of this association are indicators of good recovery from past impacts of livestock grazing. These species include Elymus caninus, Poa secunda, Hieracium scouleri var. albertinum, Agoseris heterophylla, and Piperia unalascensis.
Environmental Description: This association occurs in an upland region, that may be characterized as a north-facing basin drained by the Owyhee River. Some fault-block features occur, but much of the region is of rolling topography with low relief. The region is arid, with average annual precipitation between 18 and 30 cm, with somewhat higher precipitation at higher elevations. Much of the precipitation falls during the winter months as snow, and summers can be hot and dry.
This association is found on a mountainous ridge composed of rhyolite, from 1730-1920 m elevation. Slopes are typically east to northeast, and moderate to very steep. A seven-year precipitation record for the ridge showed annual precipitation varying from 50-56 cm. However, there is deep snow accumulation on the northeasterly aspects, which are leeward of prevailing southwesterly storms. Soils are moderately shallow (30-48 cm deep), well-drained gravelly loams over cracked rhyolite bedrock. Stones make up 30-60% of the soil volume. Cercocarpus roots extend into cracks within the bedrock.
This association is found on a mountainous ridge composed of rhyolite, from 1730-1920 m elevation. Slopes are typically east to northeast, and moderate to very steep. A seven-year precipitation record for the ridge showed annual precipitation varying from 50-56 cm. However, there is deep snow accumulation on the northeasterly aspects, which are leeward of prevailing southwesterly storms. Soils are moderately shallow (30-48 cm deep), well-drained gravelly loams over cracked rhyolite bedrock. Stones make up 30-60% of the soil volume. Cercocarpus roots extend into cracks within the bedrock.
Geographic Range: The plant association is described from one site in the Owyhee Uplands ecoregional section, in southeastern Oregon. Additional stands are expected, but have not been located, elsewhere within the Owyhee Uplands in Idaho.
Nations: US
States/Provinces: ID, OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.684006
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: G2
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.d Curl-leaf Mountain-mahogany Woodland & Scrub Group | G249 | 1.B.2.Nc.1.d |
| Alliance | A3570 Curl-leaf Mountain-mahogany Grassy Woodland Alliance | A3570 | 1.B.2.Nc.1.d |
| Association | CEGL000961 Curl-leaf Mountain-mahogany / Pinegrass Woodland | CEGL000961 | 1.B.2.Nc.1.d |
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. 1975. Ecology of curl-leaf mahogany (Cercocarpus ledifolius Nutt.) in Oregon and adjacent areas. Unpublished dissertation, Oregon State University, Corvallis. 168 pp.
- Dealy, J. E., D. A. Leckenby, and D. M. Concannon. 1981. Wildlife habitats in managed rangelands--the Great Basin of southeastern Oregon. Plant communities and their importance to wildlife. General Technical Report PNW-120. USDA Forest Service, Pacific Northwest Region, Portland, OR. 66 pp.
- Johnson, C. G., and R. R. Clausnitzer. 1992. Plant associations of the Blue and Ochoco mountains. R6-ERW-TP-036-92. USDA Forest Service, Pacific Northwest Region, Wallowa-Whitman National Forest. 163 pp. plus appendices.
- 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.