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G206 Quercus garryana - Pinus ponderosa - Pseudotsuga menziesii Forest & Woodland Group
Type Concept Sentence: This narrowly restricted group appears at or near lower treeline in foothills of the eastern Cascades in Washington and Oregon, within 65 km (40 miles) of the Columbia River Gorge and in the adjacent Columbia Plateau ecoregion and is characterized by a mix of Quercus garryana and Pinus ponderosa or Pseudotsuga menziesii.
Common (Translated Scientific) Name: Oregon White Oak - Ponderosa Pine - Douglas-fir Forest & Woodland Group
Colloquial Name: Cascadian Oregon White Oak - Conifer Forest & Woodland
Hierarchy Level: Group
Type Concept: This narrowly restricted group appears at or near lower treeline in foothills of the eastern Cascades in Washington and Oregon, within 65 km (40 miles) of the Columbia River Gorge. It also appears in the adjacent Columbia Plateau ecoregion. Most occurrences of this group are dominated by a mix of Quercus garryana and Pinus ponderosa or Pseudotsuga menziesii. Isolated, taller Pinus ponderosa or Pseudotsuga menziesii over Quercus garryana trees characterize parts of this group. Clonal Quercus garryana can create dense patches across a grassy landscape or can dominate open woodlands or even savannas. The understory may include dense stands of shrubs or, more often, be dominated by grasses, sedges or forbs. Shrub-steppe shrubs may be prominent in some stands and create a distinct tree / shrub / sparse grassland habitat, including Artemisia nova (in Oregon only), Artemisia tridentata, Chrysothamnus viscidiflorus, and Purshia tridentata. Mesic sites have an open to closed sodgrass understory dominated by Calamagrostis rubescens, Carex geyeri, Carex inops, Carex rossii, or Elymus glaucus. Drier savanna and woodland understories typically contain bunchgrass steppe species such as Festuca idahoensis or Pseudoroegneria spicata. Common exotic grasses that often appear in high abundance are Bromus tectorum and Poa bulbosa. Disjunct occurrences in the Klamath Mountains and southernmost Cascades typically have high cover of sagebrush and bitterbrush in the understory, along with other shrubs. In the Columbia River Gorge, this group appears as small to large patches in transitional areas in the Little White Salmon and White Salmon river drainages in Washington and Hood River, Rock Creek, Moiser Creek, Mill Creek, Threemile Creek, Fifteen Mile Creek, and White River drainages in Oregon. Quercus garryana can create dense patches often associated with grassland or shrubland balds within a closed Pseudotsuga menziesii forest landscape. Commonly the understory is shrubby and composed of Ceanothus integerrimus, Holodiscus discolor, Symphoricarpos albus, and Toxicodendron diversilobum. These woodlands occur at the lower treeline/ecotone between Artemisia spp. or Purshia tridentata steppe or shrubland and Pinus ponderosa and/or Pseudotsuga menziesii forest or woodland. Elevations range from 460 to 1920 m. Sites are typically warm with southern exposures with seasonal soil drought or desiccating winds. Substrates usually have bedrock, sand, or pumice soils which are excessively well-drained. Fire plays an important role in creating vegetation structure and composition in this habitat. Decades of fire suppression have led to invasion by Pinus ponderosa along lower treeline and by Pseudotsuga menziesii in the gorge and other oak patches on xeric sites in the east Cascade foothills. In the past, most of the habitat experienced frequent low-severity fires that maintained woodland or savanna conditions. The mean fire-return interval is 20 years, although variable. Soil drought plays a role, maintaining an open tree canopy in part of this dry woodland habitat.
Westside: This group also occurs of the west side of the mountain ranges from the Cascades to the North Coast Ranges in California. It is limited to the southern portions of the North Pacific region where it occurs in southwestern British Columbia, in the Puget Trough and Willamette Valley south into the Klamath Mountains and into northern California, southward through the lower southern Cascades and western Modoc Plateau and the middle and inner North Coast Ranges into Mendocino County. The vegetation ranges from savanna and woodland to forest dominated by deciduous broadleaf trees, mostly Quercus garryana. Codominance by the evergreen conifer Pseudotsuga menziesii is common, and Pinus ponderosa is important in some stands. In the south, common associates also include Quercus kelloggii and Arbutus menziesii. The predominant oaks with the higher frequency fires include Quercus kelloggii and Quercus garryana, with Quercus garryana var. garryana codominant in the central and northern Coast Ranges, Klamath Mountains and Modoc Plateau. However, Quercus garryana var. fruticosa often codominates in the northwestern Coast Ranges. More isolated patches of shrubby, clonal Quercus garryana var. semota (similar to but apparently distinct from var. fruticosa) occur farther south into the Sierra Nevada southward to the Paiute and Tehachapi mountains (southern branches of the Sierra Nevada), but these are without Pinus ponderosa or Pseudotsuga menziesii and appear to behave more as montane chaparral stands. The perennial bunchgrass component includes Danthonia californica (close to the coast), Elymus glaucus, Festuca californica, and Festuca idahoensis. A variety of native forbs also occur. Other characteristic species include Ceanothus cuneatus, Juniperus occidentalis, and Toxicodendron diversilobum. Succession in the absence of fire tends to favor increased shrub dominance in the understory, increased tree density, and increased importance of conifers, with the end result being conversion to a conifer forest. This group merges into ~Californian Broadleaf Forest & Woodland Group (G195)$$. This group occurs as both small patch and large patch in its dynamics. This west side version of this group is associated with dry, predominantly low-elevation sites and/or sites that experienced frequent presettlement fires. Elevations range from 600-1600 m (1800-4850 feet) on steep, rocky slopes where snow and cold temperatures occur. In the Willamette Valley, soils are mesic yet well-drained, and the stands are mostly large patch. In the Puget Lowland and Georgia Basin, this group is primarily found on dry sites, typically either shallow bedrock soils or deep gravelly glacial outwash soils. It occurs on various soils in the interior valleys of the Klamath Mountains, and on shallow soils of "bald hill" toward the coast. Even where more environmentally limited, the group is strongly associated with a historic low-severity fire regime. With frequent annual burning (at lower elevations and on warmer sites), this group is an open to dense woodland of large oaks with well-developed grassy understories of native perennial bunchgrass. Succession in the absence of fire tends to favor increased shrub dominance in the understory, increased tree density, and increased importance of conifers, with the end result being conversion to a conifer forest. This group merges into ~Californian Broadleaf Forest & Woodland Group (G195)$$. This group occurs as both small patch and large patch in its dynamics.
Westside: This group also occurs of the west side of the mountain ranges from the Cascades to the North Coast Ranges in California. It is limited to the southern portions of the North Pacific region where it occurs in southwestern British Columbia, in the Puget Trough and Willamette Valley south into the Klamath Mountains and into northern California, southward through the lower southern Cascades and western Modoc Plateau and the middle and inner North Coast Ranges into Mendocino County. The vegetation ranges from savanna and woodland to forest dominated by deciduous broadleaf trees, mostly Quercus garryana. Codominance by the evergreen conifer Pseudotsuga menziesii is common, and Pinus ponderosa is important in some stands. In the south, common associates also include Quercus kelloggii and Arbutus menziesii. The predominant oaks with the higher frequency fires include Quercus kelloggii and Quercus garryana, with Quercus garryana var. garryana codominant in the central and northern Coast Ranges, Klamath Mountains and Modoc Plateau. However, Quercus garryana var. fruticosa often codominates in the northwestern Coast Ranges. More isolated patches of shrubby, clonal Quercus garryana var. semota (similar to but apparently distinct from var. fruticosa) occur farther south into the Sierra Nevada southward to the Paiute and Tehachapi mountains (southern branches of the Sierra Nevada), but these are without Pinus ponderosa or Pseudotsuga menziesii and appear to behave more as montane chaparral stands. The perennial bunchgrass component includes Danthonia californica (close to the coast), Elymus glaucus, Festuca californica, and Festuca idahoensis. A variety of native forbs also occur. Other characteristic species include Ceanothus cuneatus, Juniperus occidentalis, and Toxicodendron diversilobum. Succession in the absence of fire tends to favor increased shrub dominance in the understory, increased tree density, and increased importance of conifers, with the end result being conversion to a conifer forest. This group merges into ~Californian Broadleaf Forest & Woodland Group (G195)$$. This group occurs as both small patch and large patch in its dynamics. This west side version of this group is associated with dry, predominantly low-elevation sites and/or sites that experienced frequent presettlement fires. Elevations range from 600-1600 m (1800-4850 feet) on steep, rocky slopes where snow and cold temperatures occur. In the Willamette Valley, soils are mesic yet well-drained, and the stands are mostly large patch. In the Puget Lowland and Georgia Basin, this group is primarily found on dry sites, typically either shallow bedrock soils or deep gravelly glacial outwash soils. It occurs on various soils in the interior valleys of the Klamath Mountains, and on shallow soils of "bald hill" toward the coast. Even where more environmentally limited, the group is strongly associated with a historic low-severity fire regime. With frequent annual burning (at lower elevations and on warmer sites), this group is an open to dense woodland of large oaks with well-developed grassy understories of native perennial bunchgrass. Succession in the absence of fire tends to favor increased shrub dominance in the understory, increased tree density, and increased importance of conifers, with the end result being conversion to a conifer forest. This group merges into ~Californian Broadleaf Forest & Woodland Group (G195)$$. This group occurs as both small patch and large patch in its dynamics.
Diagnostic Characteristics: Forests and woodlands dominated by a mix of Quercus garryana and Pinus ponderosa or Pseudotsuga menziesii. Shrubs and herbaceous species are Intermountain Basin species, diagnostic of the Columbia Plateau and Great Basin or Rocky Mountains species. Bakker and Colasurdo (2010) concluded that Quercus garryana tree densities in all size classes were higher in eastern Washington than on western sites. Westside: Dry low-elevation stands dominated by Quercus garryana which can have some Arbutus menziesii, Quercus chrysolepis, or Quercus kelloggii. Pseudotsuga menziesii is common, and Pinus ponderosa occurs occasionally but is not diagnostic. Other characteristic species include Ceanothus cuneatus, Juniperus occidentalis, Symphoricarpos albus, and Toxicodendron diversilobum.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This group is a matrix type with stands of either pure Pinus ponderosa, pure Quercus garryana, or mixed Pinus ponderosa - (Pseudotsuga menziesii) - Quercus garryana. The description of ~Pinus ponderosa - Quercus garryana / Arctostaphylos viscida / Festuca californica Woodland (CEGL000880)$$ indicates that it is a transitional type or a clustering of plots from the interbasins (Festuca idahoensis and Pseudoroegneria spicata) and California (Festuca californica, Toxicodendron diversilobum).
Quercus garryana var. fruticosa (and other shrub-form varieties) are not included in this group; in California, they are considered part of montane deciduous scrub, occurring at higher elevations than the tree-form Quercus garryana var. garryana.
Quercus garryana var. fruticosa (and other shrub-form varieties) are not included in this group; in California, they are considered part of montane deciduous scrub, occurring at higher elevations than the tree-form Quercus garryana var. garryana.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Medium-tall woodlands and forests often with emergent taller conifer trees. Undergrowth of medium-height shrubs and an open layer of grasses and or forbs is typical. Also medium-height open-canopy deciduous broadleaf woodlands with grassy understory.
Floristics: Most occurrences of this group are dominated by Quercus garryana with and without Pinus ponderosa or Pseudotsuga menziesii. Isolated, taller Pinus ponderosa or Pseudotsuga menziesii over Quercus garryana trees characterize part of this group. Clonal Quercus garryana can create dense tree or tall-shrub patches across a grassy landscape or can dominate open woodlands or even savannas. The understory may include dense stands of shrubs or, more often, be dominated by grasses, sedges or forbs. Shrub-steppe shrubs may be prominent in some stands and create a distinct tree / shrub / sparse grassland habitat, including Purshia tridentata, Artemisia tridentata, Artemisia nova, and Chrysothamnus viscidiflorus. Understories are generally dominated by herbaceous species, especially graminoids. Mesic sites have an open to closed sodgrass understory dominated by Calamagrostis rubescens, Carex geyeri, Carex rossii, Carex inops, or Elymus glaucus. Drier savanna and woodland understories typically contain bunchgrass steppe species such as Festuca idahoensis or Pseudoroegneria spicata. Common exotic grasses that often appear in high abundance are Bromus tectorum and Poa bulbosa. These woodlands occur at the lower treeline/ecotone between Artemisia spp. or Purshia tridentata steppe or shrubland and Pinus ponderosa and/or Pseudotsuga menziesii forests or woodlands. In the Columbia River Gorge, this group appears as small to large patches in transitional areas in the Little White Salmon and White Salmon river drainages in Washington and Hood River, Rock Creek, Moiser Creek, Mill Creek, Threemile Creek, Fifteen Mile Creek, and White River drainages in Oregon. Quercus garryana can create dense patches often associated with grassland or shrubland balds within a closed Pseudotsuga menziesii forest landscape. Commonly the understory is shrubby and composed of Ceanothus integerrimus, Holodiscus discolor, Symphoricarpos albus, and Toxicodendron diversilobum. Fire plays an important role in creating vegetation structure and composition in this habitat. Decades of fire suppression have led to invasion by Pinus ponderosa along lower treeline and by Pseudotsuga menziesii in the gorge and other oak patches on xeric sites in the east Cascade foothills.
Westside floristics: With frequent annual burning (at lower elevations and on warmer sites), this group is an open to dense woodland of large oaks with well-developed grassy understories of native perennial bunchgrass. The perennial bunchgrass component includes Danthonia californica (close to the coast), Elymus glaucus, Festuca californica, and Festuca idahoensis. A variety of native forbs also occur. Other characteristic species include Ceanothus cuneatus, Juniperus occidentalis, and Toxicodendron diversilobum. The predominant oaks with the higher frequency fires include Quercus kelloggii and Quercus garryana, with Quercus garryana var. garryana codominant in the central and northern Coast Ranges. Succession in the absence of fire tends to favor increased shrub dominance in the understory, increased tree density, and increased importance of conifers, with the end result being conversion to a conifer forest. The vegetation ranges from savanna and woodland to forest dominated by deciduous broadleaf trees, mostly Quercus garryana. Codominance by the evergreen conifer Pseudotsuga menziesii is common, and Pinus ponderosa is important in some stands. In the south, common associates also include Arbutus menziesii and Quercus kelloggii.
Westside floristics: With frequent annual burning (at lower elevations and on warmer sites), this group is an open to dense woodland of large oaks with well-developed grassy understories of native perennial bunchgrass. The perennial bunchgrass component includes Danthonia californica (close to the coast), Elymus glaucus, Festuca californica, and Festuca idahoensis. A variety of native forbs also occur. Other characteristic species include Ceanothus cuneatus, Juniperus occidentalis, and Toxicodendron diversilobum. The predominant oaks with the higher frequency fires include Quercus kelloggii and Quercus garryana, with Quercus garryana var. garryana codominant in the central and northern Coast Ranges. Succession in the absence of fire tends to favor increased shrub dominance in the understory, increased tree density, and increased importance of conifers, with the end result being conversion to a conifer forest. The vegetation ranges from savanna and woodland to forest dominated by deciduous broadleaf trees, mostly Quercus garryana. Codominance by the evergreen conifer Pseudotsuga menziesii is common, and Pinus ponderosa is important in some stands. In the south, common associates also include Arbutus menziesii and Quercus kelloggii.
Dynamics: Fire plays an important role in creating vegetation structure and composition in this habitat. Decades of fire suppression have led to invasion by Pinus ponderosa along lower treeline and by Pseudotsuga menziesii in the gorge and other oak patches on xeric sites in the east Cascade foothills. Most of the habitat experienced frequent low-severity fires that maintained woodland or savanna conditions. The mean fire-return interval is 20 years, although variable. Landfire VDDT models: #R OAP1 Oregon White Oak-Ponderosa Pine model describes general successional pathways treating drier pine succession separate from more mesic Douglas-fir pathways. Frequent annual burning (at lower elevations and on warmer sites) is required to maintain the open to dense woodland of large oaks with well-developed grassy understories of native perennial bunchgrass. Landfire VDDT models: #R OWOA Oregon White Oak applies to southern occurrences.
Environmental Description: This narrowly restricted group appears at or near lower treeline in foothills of the eastern Cascades in Washington and Oregon within 65 km (40 miles) of the Columbia River Gorge. It also appears in the adjacent Columbia Plateau ecoregion associated with low-elevation slopes and valley margins. This area receives 50-80 cm of annual precipitation, falling mostly as winter rain and snow. Elevation ranges from 460 to 1920 m. Stands often occur on warm sites with southern exposures with seasonal soil drought or desiccating winds. Substrates usually have bedrock, sand, or pumice soils which drain quickly (Reid et al.1999).
Westside environment: This group is limited to southwestern British Columbia, in the Puget Trough and Willamette Valley south into the Klamath Mountains and into northern California, where it is found throughout the Sierra Nevada and Coast Ranges foothills and lower montane elevations from 600-1600 m (1800-4850 feet) on steep, rocky slopes where snow and cold temperatures occur. This group is associated with dry, predominantly low-elevation sites and/or sites that experienced frequent presettlement fires. In the Willamette Valley, soils are mesic yet well-drained, and the stands are mostly large patch. In the Puget Lowland and Georgia Basin, this group is primarily found on dry sites, typically either shallow bedrock soils or deep gravelly glacial outwash soils. It occurs on various soils in the interior valleys of the Klamath Mountains, and on shallow soils of "bald hills" toward the coast.
Westside environment: This group is limited to southwestern British Columbia, in the Puget Trough and Willamette Valley south into the Klamath Mountains and into northern California, where it is found throughout the Sierra Nevada and Coast Ranges foothills and lower montane elevations from 600-1600 m (1800-4850 feet) on steep, rocky slopes where snow and cold temperatures occur. This group is associated with dry, predominantly low-elevation sites and/or sites that experienced frequent presettlement fires. In the Willamette Valley, soils are mesic yet well-drained, and the stands are mostly large patch. In the Puget Lowland and Georgia Basin, this group is primarily found on dry sites, typically either shallow bedrock soils or deep gravelly glacial outwash soils. It occurs on various soils in the interior valleys of the Klamath Mountains, and on shallow soils of "bald hills" toward the coast.
Geographic Range: This narrowly restricted group appears at or near lower treeline in the foothills of the eastern Cascades in Washington and Oregon within 65 km (40 miles) of the Columbia River Gorge. It also appears in the adjacent Columbia Plateau ecoregion. Disjunct occurrences in the Klamath Mountains and southernmost Cascades may have big sagebrush and bitterbrush in the understory, along with other shrubs.
Westside range: This group occurs primarily in the Puget Trough and Willamette Valley and extends southward at low elevations in the Klamath Mountains on both sides of the Oregon/California stateline, and continues south throughout the Sierra Nevada and Coast Ranges foothills and lower montane of California and Oregon at elevations from 600-1600 m (1800-4850 feet).
Westside range: This group occurs primarily in the Puget Trough and Willamette Valley and extends southward at low elevations in the Klamath Mountains on both sides of the Oregon/California stateline, and continues south throughout the Sierra Nevada and Coast Ranges foothills and lower montane of California and Oregon at elevations from 600-1600 m (1800-4850 feet).
Nations: CA,US
States/Provinces: BC, CA, OR, WA
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.833213
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
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 | A3327 Oregon White Oak - Ponderosa Pine / Geyer''s Sedge Woodland Alliance | A3327 | 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 |
Concept Lineage: G204 merged into G206 (DFL 7-12)
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: < Interior Ponderosa Pine: 237 (Eyre 1980)
< Oregon White Oak: 233 (Eyre 1980)
< Oregon White Oak: 233 (Eyre 1980)
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