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CEGL000042 Abies lowiana - Chamaecyparis lawsoniana / Quercus sadleriana / Leucothoe davisiae - Rhododendron macrophyllum Forest
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Sierra White Fir - Port Orford-cedar / Deer Oak / Sierra Laurel - Pacific Rhododendron Forest
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This giant coniferous forest association occurs in narrow draws and streamsides in southwestern Oregon and possibly northern California at an average elevation of 1000 m. All known stands are within the Silver Creek drainage, southwest of Galice, Oregon. This is one of the rare locations where Tsuga heterophylla occurs inland from the Coast Ranges with Abies lowiana also present. The geology within the range of this forest type is very complex. Most stands of this association seem to grow upon coarse grained, colluvium, or colluvium mixed with alluvium derived from granitic to gabbroic rocks, sometimes mixed with ultramafics. The soils are shallow with an average depth to the C horizon of 43 cm. This is a fairly dense forest community, with tree canopy cover averaging 86%. The tree canopy is codominated by Chamaecyparis lawsoniana, Tsuga heterophylla, and Abies lowiana, often with a significant component of Pseudotsuga menziesii. This association often contains a significant amount of Thuja plicata, Chrysolepis chrysophylla, Pseudotsuga menziesii, and/or Alnus rubra. The shrub stratum averages 50% cover. Shrubs are either diffuse and continuous over large areas, or confined to canopy openings in younger stands with very dense trees. Leucothoe davisiae attains the highest cover of any shrub in the community, and is usually found as low streamside mats. Taller individuals of Vaccinium parvifolium and Quercus sadleriana are scattered away from the stream, and share the tall-shrub layer with immature conifers, the hardwood Notholithocarpus densiflorus and Rhododendron macrophyllum. The herbaceous layer attains only 16% cover, and no herb dominates. The presence of Tsuga heterophylla and Abies lowiana in the tree canopy differentiate this association from other Chamaecyparis lawsoniana associations.
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 structurally diverse association is dominated by needle-leaved evergreen trees, with total tree cover averaging 86%. Chamaecyparis lawsoniana dominates (with 56% cover), with Pseudotsuga menziesii and Tsuga heterophylla adding another 19% and 15% cover, respectively. Abies lowiana (= Abies concolor var. lowiana) is important in half the stands sampled. Seven other tree species may occur in some stands, including the broad-leaved species Alnus rubra and Chrysolepis chrysophylla (= Castanopsis chrysophylla). The conifers Abies lowiana, Chamaecyparis lawsoniana and Tsuga heterophylla dominate the tree regeneration, with 30% cover of seedlings. Both tall- and short-shrub layers are composed of broad-leaved species and well-developed, with total cover of 50%. As a whole, the shrub layer is either diffuse and continuous over large areas, or is lacking in young dense stands of trees, where only occasional shrubby openings occur. Several shrubs show high constancy, including the tall evergreens Quercus sadleriana (6% cover), Rhododendron macrophyllum (9% cover), and Notholithocarpus densiflorus (= Lithocarpus densiflorus) (1% cover), and the deciduous Vaccinium parvifolium (1% cover). Shorter shrubs with high constancy include Leucothoe davisiae (14% cover), Gaultheria shallon (6% cover), and Mahonia nervosa (2% cover), all evergreen. The herbaceous layer is composed of perennial forbs and is moderately sparse, with only 16% total cover and no dominant species.
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 (0-5000 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 76 cm (30 inches) annually on the eastern slope, where a rainshadow effect is pronounced and summers are very dry.
This association is found from 900 to 1260 m (2980-4140 feet) elevation, on western and northwestern aspects of a major ridge in the northeastern portion of the range of Chamaecyparis lawsoniana. Sites are along tributaries of the Rogue River, within narrow draws having a variety of slopes, from gentle to steep (range from 2-43% slopes). Soils are derived from colluvium or mixed colluvium and alluvium of a variety of rocks types, but predominantly coarse-grained granitics to gabbroic rocks, in some cases mixed with ultramafics. They are relatively shallow (averaging 43 cm depth to top of C horizon), and textures are typically gravelly-cobbly silt loams to silt clay loams, over very cobbly and stony C horizons. Stands with slopes less than about 10% often have standing water on the ground surface during the summer months.
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 76 cm (30 inches) annually on the eastern slope, where a rainshadow effect is pronounced and summers are very dry.
This association is found from 900 to 1260 m (2980-4140 feet) elevation, on western and northwestern aspects of a major ridge in the northeastern portion of the range of Chamaecyparis lawsoniana. Sites are along tributaries of the Rogue River, within narrow draws having a variety of slopes, from gentle to steep (range from 2-43% slopes). Soils are derived from colluvium or mixed colluvium and alluvium of a variety of rocks types, but predominantly coarse-grained granitics to gabbroic rocks, in some cases mixed with ultramafics. They are relatively shallow (averaging 43 cm depth to top of C horizon), and textures are typically gravelly-cobbly silt loams to silt clay loams, over very cobbly and stony C horizons. Stands with slopes less than about 10% often have standing water on the ground surface during the summer months.
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 the western and northwestern aspects of a major mountain ridge in the Klamath Mountains of Curry and Josephine County, Oregon. This association occurs in an unusual region with several unique floristic features. It is intermediate in elevational range, falling within portions of both the Tsuga heterophylla and Abies concolor zones; it is separated from the main range of Chamaecyparis lawsoniana by the interior valleys of the Rogue and Illinois rivers; and it is one of the few areas where Tsuga heterophylla extends inland in southern Oregon where Abies concolor is also present.
Nations: US
States/Provinces: CA?, OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.686330
Confidence Level: Low
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.f Western Hemlock - Sitka Spruce North-Central Pacific Rainforest Group | G751 | 1.B.2.Nd.3.f |
| Alliance | A3606 Port Orford-cedar - Sitka Spruce Forest Alliance | A3606 | 1.B.2.Nd.3.f |
| Association | CEGL000042 Sierra White Fir - Port Orford-cedar / Deer Oak / Sierra Laurel - Pacific Rhododendron Forest | CEGL000042 | 1.B.2.Nd.3.f |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- 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.
- 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.
- 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.
- Thilenius, J. F. 1968. The Quercus garryana forests of the Willamette Valley, Oregon. Ecology 49:1124-1133.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.
- Zobel, D. B., L. F. Roth, and G. M. Hawk. 1985. Ecology, pathology, and management of Port-Orford cedar (Chamaecyparis lawsoniana). General Technical Report GTR-PNW-194. USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Portland, OR. 161 pp.