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CEGL000046 Chamaecyparis lawsoniana - Tsuga heterophylla / Polystichum munitum Forest
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Port Orford-cedar - Western Hemlock / Western Swordfern Forest
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This giant conifer association grows on mesic sites between 300-800 m elevation in southwestern Oregon and northwestern California. Stands are found on moist benches and well-watered slopes up to 35%. Soils are well developed, gravelly silt loams of comparative depth. The tree canopy is dominated by Pseudotsuga menziesii, Chamaecyparis lawsoniana and Tsuga heterophylla. Abies grandis, Alnus rubra, Acer macrophyllum, and Notholithocarpus densiflorus are common associates. The vigorous immature conifer layer averages 47% cover and is dominated by Tsuga heterophylla. The shrub stratum is poorly developed, attaining an average of only 9% cover. Gaultheria shallon and Mahonia nervosa) are common in the low-shrub stratum, while Notholithocarpus densiflorus dominates the tall-shrub layer. The dense herbaceous layer is dominated by Polystichum munitum and Oxalis oregana which make up 80% of the herbaceous cover. Moss cover averages 39%. The high cover of the herbaceous layer (63%), with dominance by Polystichum munitum and Oxalis oregana differentiate this community from other Chamaecyparis lawsoniana forest 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: As described here, this association is structurally variable, in that a few stands have well-developed tall- and short-shrub layers, while most stands are typically low in shrub abundance. The tree canopy (with 85% average cover) is dominated by needle-leaved evergreen species, primarily Chamaecyparis lawsoniana, with lesser amounts of Pseudotsuga menziesii and Tsuga heterophylla. The tree subcanopy (with 47% average cover) is a mix of saplings and small trees of the above conifers, as well as mature individuals of the broad-leaved deciduous trees Alnus rubra and Acer macrophyllum, and the evergreen Notholithocarpus densiflorus (= Lithocarpus densiflorus). Typically most stands have poorly developed shrub layers, although several shrubs have high constancy, including the evergreen Gaultheria shallon and Mahonia nervosa (= var. nervosa), and the deciduous Vaccinium parvifolium. The herbaceous layer is strongly dominated by the perennial fern Polystichum munitum, with lesser amounts of the forb Oxalis oregana. These two species average 55% cover, and total herbaceous cover is 60%. There are many forbs present in trace amounts. Moss cover averages 40% and is composed of mesic- to wet-site species. In a few stands both tall- and short-shrub layers are well-developed with cover as high as 90%. Species are primarily broad-leaved deciduous, such as Acer macrophyllum, Alnus rubra, Corylus cornuta, Cornus nuttallii, and the evergreen Vaccinium ovatum. The herbaceous layer is much the same as described above.
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 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 300 to 808 m (980-2650 feet) elevation, predominantly on benches and lower river terraces, and occasionally on side- or toeslopes with up to 35% slope. Aspects are primarily northern. Soils are well-developed and derived from a variety of parent materials, the most common being alluvium of sedimentary origins. They are deep (an average of 66 cm to the surface of the C horizon), vary from poorly to well-drained, and have textures of silty loams to silty clay loams, with gravels and cobbles throughout the profile. Soil moisture is typically high year-round, but is primarily subsurface flow from sideslopes.
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 300 to 808 m (980-2650 feet) elevation, predominantly on benches and lower river terraces, and occasionally on side- or toeslopes with up to 35% slope. Aspects are primarily northern. Soils are well-developed and derived from a variety of parent materials, the most common being alluvium of sedimentary origins. They are deep (an average of 66 cm to the surface of the C horizon), vary from poorly to well-drained, and have textures of silty loams to silty clay loams, with gravels and cobbles throughout the profile. Soil moisture is typically high year-round, but is primarily subsurface flow from sideslopes.
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 coastal strip in southern Coos and northern Curry counties, Oregon, and adjacent California.
Nations: US
States/Provinces: CA, OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.689308
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: G1
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 | CEGL000046 Port Orford-cedar - Western Hemlock / Western Swordfern Forest | CEGL000046 | 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 - Tsuga heterophylla / Polystichum munitum (Atzet et al. 1996)
= Chamaecyparis lawsoniana - Tsuga heterophylla / Polystichum munitum (Hawk 1977)
= Chamaecyparis lawsoniana - Tsuga heterophylla / Polystichum munitum (Hawk 1977)
- 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.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.