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CEGL000043 Chamaecyparis lawsoniana - Pseudotsuga menziesii / Notholithocarpus densiflorus / Gaultheria shallon Forest
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Port Orford-cedar - Douglas-fir / Tanoak / Salal Forest
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This conifer forest association occurs very locally in southwestern Oregon and northern California. These forests form open stands with a dense shrub layer. Stands are found between 400-910 m elevation, as strips along perennial streams or on well protected benches with frequent seeps. The tree canopy averages 80% cover, and is dominated by Chamaecyparis lawsoniana and Pseudotsuga menziesii. Taxus brevifolia and Notholithocarpus densiflorus are also common, and there are more species of Pinus found in this association than any other Chamaecyparis lawsoniana association. Pinus attenuata, Pinus lambertiana, Pinus monticola, Arbutus menziesii, Umbellularia californica, Quercus chrysolepis, and Chrysolepis chrysophylla are all occasionally found in the tree layer. The typically dense shrub layer attains 97% cover and is a diagnostic character of this association. Because of the semi-mesic environments and ultramafic soils that this forest association occurs on, some of the hardwood species present are prevented from attaining tree stature. The shrub form of Notholithocarpus densiflorus is the most common species in this layer. Other common shrubs include Gaultheria shallon, Umbellularia californica, Vaccinium ovatum, Quercus chrysolepis, and Rhododendron occidentale. The herbaceous layer only averages 8% cover and has very low species diversity. Only 6 species consistently achieve more than trace amounts of cover. Polystichum munitum and Xerophyllum tenax are the most common herbs. Ultramafic indicators are common among the herbs.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This association may be confused with ~Chamaecyparis lawsoniana - Pseudotsuga menziesii / (Rhododendron macrophyllum) / Xerophyllum tenax Forest (CEGL000044)$$ or ~Chamaecyparis lawsoniana - Tsuga heterophylla / Gaultheria shallon - Rhododendron macrophyllum Forest (CEGL000045)$$, because this type occurs on ultramafic substrates similar to the former association, but with moisture characteristics like the latter. However, this association is distinguished from the other Chamaecyparis lawsoniana types by the well developed shrub layer, the lack of Tsuga heterophylla due to climatic factors, and the high cover and diversity of Pinus spp. in the tree canopy.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This forest association is structurally diverse, with a canopy dominated by needle-leaved evergreen trees, a subcanopy of needle-leaved and broad-leaved evergreen woody species, and both tall- and short-shrub layers of mixed evergreen and deciduous species. The trees Chamaecyparis lawsoniana and Pseudotsuga menziesii together have 85% cover, but Chamaecyparis lawsoniana is always more abundant and dominates the tree subcanopy as saplings. The shrub layers are well-developed and diverse, with 97% average cover and 17 commonly occurring species. Several broad-leaved evergreen sclerophylls occur in the subcanopy, but they are most commonly tall shrubs. Of these Notholithocarpus densiflorus (= Lithocarpus densiflorus) is the most abundant, averaging 25% cover. Other sclerophylls include Arbutus menziesii, Umbellularia californica, Chrysolepis chrysophylla (= Castanopsis chrysophylla), Quercus chrysolepis, Quercus sadleriana and Quercus vacciniifolia. Rhododendron macrophyllum and Rhododendron occidentale dominate the tall-shrub layer, with 26% average cover, and Gaultheria shallon dominates the low-shrub layer (18% cover). The herbaceous layer is typically sparse, with an average of only 8% cover. The perennial fern Polystichum munitum and the forbs Goodyera oblongifolia, Xerophyllum tenax, Trillium ovatum, Vancouveria planipetala, and Chimaphila menziesii are the most constant and abundant herbaceous species. Many of the forbs are indicators of ultramafic substrates. Moss cover averages 19%.
Dynamics: No Data Available
Environmental Description: This association occurs in a mountainous region (Klamath Mountains Province) of rugged, deeply dissected terrain. Geologically, the province is very complex and of very old deposits. Rock types include volcanic tuffs and sedimentary rocks which have been metamorphosed into schists, gneisses, marbles, and other metavolcanic and metasedimentary rocks. Sandstones, siltstones and shales have been deposited near the coast. The most notable rock types are granitics and elongated, stringer-like outcrops of serpentine. Elevations of this region vary from sea level to over 1525 m (5000 feet).
The climate of the region is maritime, with wet, mild winters, cool, relatively dry summers at higher elevations and warm to hot summers at lower elevations, prolonged cloudy periods, and high annual precipitation. Precipitation varies from over 178 cm (70 inches) annually near the coast, to less than 30 inches annually on the eastern slope, where a rainshadow effect is pronounced and summers are very dry.
This association occurs from 400 to 910 m (1310-2990 feet) elevation, typically below 850 m (2780 feet) in the north of its distribution, and above 580 m (1900 feet) in the south. It is common on benches, along perennial stream drainages, and on gently rolling sites that have seeps or standing water. Slopes are variable, ranging from flat to very steep, and it is found on all aspects except south. Parent materials are primarily mixed colluvium of ultramafic materials, or of granodioritic, ultramafic and metavolcanic materials. Soils typically have many coarse fragments in all horizons, and textures range from silt-loams to clay loams, all with gravels, cobbles, and stones. The average depth to the C horizon is 63 cm.
The climate of the region is maritime, with wet, mild winters, cool, relatively dry summers at higher elevations and warm to hot summers at lower elevations, prolonged cloudy periods, and high annual precipitation. Precipitation varies from over 178 cm (70 inches) annually near the coast, to less than 30 inches annually on the eastern slope, where a rainshadow effect is pronounced and summers are very dry.
This association occurs from 400 to 910 m (1310-2990 feet) elevation, typically below 850 m (2780 feet) in the north of its distribution, and above 580 m (1900 feet) in the south. It is common on benches, along perennial stream drainages, and on gently rolling sites that have seeps or standing water. Slopes are variable, ranging from flat to very steep, and it is found on all aspects except south. Parent materials are primarily mixed colluvium of ultramafic materials, or of granodioritic, ultramafic and metavolcanic materials. Soils typically have many coarse fragments in all horizons, and textures range from silt-loams to clay loams, all with gravels, cobbles, and stones. The average depth to the C horizon is 63 cm.
Geographic Range: One of the primary dominant species, Port Orford-cedar, is very local, restricted to southwestern Oregon and northwestern California. This association is even more local, found only in upper reaches of Silver and Howard creeks, and near Little Sugarloaf Peak in central Curry and Josephine County, in Oregon, and at mid elevations along the western edge of the Six Rivers National Forest in northern California.
Nations: US
States/Provinces: CA, OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.689805
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.3 Western Hemlock - Sitka Spruce - Redwood Rainforest Macrogroup | M024 | 1.B.2.Nd.3 |
| Group | 1.B.2.Nd.3.a Redwood Forest Group | G235 | 1.B.2.Nd.3.a |
| Alliance | A0104 Port Orford-cedar Forest Alliance | A0104 | 1.B.2.Nd.3.a |
| Association | CEGL000043 Port Orford-cedar - Douglas-fir / Tanoak / Salal Forest | CEGL000043 | 1.B.2.Nd.3.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Chamaecyparis lawsoniana association (Stumpf et al. 2017)
< Pseudotsuga-sclerophyll vegetation type (Whittaker 1960) [wetter sites.]
< Pseudotsuga-sclerophyll vegetation type (Whittaker 1960) [wetter sites.]
- Atzet, T. A., D. E. White, L. A. McCrimmon, P. A. Martinez, P. R. Fong, and V. D. Randall. 1996. Field guide to the forested plant associations of southwestern Oregon. Technical Paper R6-NR-ECOL-TP-17-96. USDA Forest Service, Pacific Northwest Region, Portland, OR.
- Atzet, T., and D. L. Wheeler. 1984. Preliminary plant associations of the Siskiyou Mountains Province, Siskiyou National Forest. USDA Forest Service, Pacific Northwest Region, Portland, OR.
- 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.
- Hawk, G. M. 1977. A comparative study of temperate Chamaecyparis forests. Unpublished dissertation, Oregon State University, Corvallis. 194 pp.
- Jimerson, T. J. 1994. A field guide to the Port Orford cedar plant associations in northwestern California. Pacific Southwest Research Station PSW-R5-ECOL-TP-OO2. Six Rivers National Forest, Eureka, CA. 109 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.
- Stumpf, K. A., Cogan Technology, and Kier Associates. 2017. Vegetation mapping and classification project: Redwood National and State Parks, California. Natural Resource Report NPS/REDW/NRR--2017/1431. National Park Service, Fort Collins, CO. 270 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.
- Whittaker, R. H. 1960. Vegetation of the Siskiyou Mountains, Oregon and California. Ecological Monographs 30:279-338.