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CEGL000931 Quercus garryana - Quercus kelloggii / Toxicodendron diversilobum Woodland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Oregon White Oak - California Black Oak / Pacific Poison-oak Woodland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This mixed woodland occurs in northern California and southwestern Oregon. Large stands of this community are rare. Generally it is found on valley bottoms or south-facing slopes in a mixed conifer-hardwood matrix. This association is dominated by Quercus garryana and Quercus kelloggii. Many stands show some invasion of conifers, primarily Pseudotsuga menziesii and Pinus ponderosa, but in no stands of this community are conifers found in the canopy. Arbutus menziesii can be codominant in stands, and is occasionally included in the association name. Canopy varies from very open to fairly closed woodlands (15-70%). In high-quality stands, the trees are large and fairly widely spaced. With extended fire suppression, trees become more dense and smaller. The shrub layer is dominated by Toxicodendron diversilobum. On flats and moister aspects, Symphoricarpos albus and Rosa gymnocarpa can be found, in some areas with introduced Rubus species. Grasses dominate the forb layer in good condition stands, with Elymus glaucus, Festuca californica, Melica spp. dominant. Due to impacts of livestock, introduced grasses (Arrhenatherum elatius, Taeniatherum caput-medusae, Cynosurus echinatus, and Dactylis glomerata) and forbs (Anthriscus caucalis, Daucus carota, and Centaurea spp.) are more common understory components. According to historical records, it occurred as a savanna type and a woodland when widespread fires occurred across the landscape. Quercus garryana - Quercus kelloggii savannas are included in this type.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This is a poorly studied community type. It is the only Oregon white oak - California black oak mixed woodland in the USNVC, and represents a fairly broad mix of types. If it was not so rare, threatened, and poorly inventoried, at a minimum it would likely be split into a riparian - valley bottom type and an upland type. In all probability, there was also an Oregon white oak - California black oak savanna, and tiny examples of this can be found in the southern Willamette Valley and the Umpqua Valley. Given the lack of data, it is best to consider all these types as one association.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This association is dominated by Quercus garryana and Quercus kelloggii. Many stands show some invasion of conifers, primarily Pseudotsuga menziesii and Pinus ponderosa, but in no stands of this community are conifers found in the canopy. Arbutus menziesii can be codominant in stands, and is occasionally included in the association name. Canopy varies from very open to fairly closed woodlands (15-70%). In high-quality stands, the trees are large and fairly widely spaced. With extended fire suppression, trees become more dense and smaller. The shrub layer is dominated by Toxicodendron diversilobum. On flats and moister aspects, Symphoricarpos albus and Rosa gymnocarpa can be found, in some areas with introduced Rubus species. Grasses dominate the forb layer in good condition stands, with Elymus glaucus, Festuca californica, Melica spp. dominant. Due to impacts of livestock, introduced grasses (Arrhenatherum elatius, Taeniatherum caput-medusae, Cynosurus echinatus, and Dactylis glomerata) and forbs (Anthriscus caucalis (= Anthriscus scandicina), Daucus carota, and Centaurea spp.) are more common understory components.
Dynamics: According to historical records, it occurred as a savanna type and a woodland when widespread fires occurred across the landscape. Quercus garryana - Quercus kelloggii savannas are included in this type.
Environmental Description: Generally it is found on valley bottoms or south-facing slopes in a mixed conifer-hardwood matrix.
Geographic Range: This type is found from the southern end of the Willamette Valley to northern California. In California, both of these oak species give way to other species south of the Klamath Mountains.
Nations: US
States/Provinces: CA, OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.689932
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.Nd Vancouverian Forest & Woodland Division | D192 | 1.B.2.Nd |
| Macrogroup | 1.B.2.Nd.1 Southern Vancouverian Dry Foothill Forest & Woodland Macrogroup | M886 | 1.B.2.Nd.1 |
| Group | 1.B.2.Nd.1.b Oregon White Oak - Ponderosa Pine - Douglas-fir Forest & Woodland Group | G206 | 1.B.2.Nd.1.b |
| Alliance | A3328 Oregon White Oak - Douglas-fir / Pacific Poison-oak Forest & Woodland Alliance | A3328 | 1.B.2.Nd.1.b |
| Association | CEGL000931 Oregon White Oak - California Black Oak / Pacific Poison-oak Woodland | CEGL000931 | 1.B.2.Nd.1.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Quercus garryana - Quercus kelloggii / Toxicodendron diversilobum (Sawyer et al. 2009) [71.030.14]
= Quercus garryana - Quercus kelloggii / Toxicodendron diversilobum Forest (Buechling et al. 2008)
= Quercus garryana - Quercus kelloggii / Toxicodendron diversilobum Forest (Buechling et al. 2008)
- 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.
- Buechling, A., E. Alverson, J. Kertis, and G. Fitzpatrick. 2008. Classification of oak vegetation in the Willamette Valley. Oregon Natural Heritage Information Center, Oregon State University, Corvallis. 71 pp.
- Jimerson, T. M. 1993. Preliminary plant associations of the Klamath province, Six Rivers and Klamath national forests. Unpublished report. USDA Forest Service, Eureka, CA.
- 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.
- Riegel, G. M., B. G. Smith, and J. F. Franklin. 1992. Foothill oak woodlands of the interior valleys of southwestern Oregon. Northwest Science 66(2):66-76.
- Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.
- Smith, W. P. 1985. Plant associations within the interior valleys of the Umpqua River Basin, Oregon. Journal of Range Management 38:526-530.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.