Print Report

CEGL003418 Populus balsamifera ssp. trichocarpa - Picea sitchensis - (Acer macrophyllum) / Oxalis oregana Riparian Forest

Type Concept Sentence: No Data Available


Common (Translated Scientific) Name: Black Cottonwood - Sitka Spruce - (Bigleaf Maple) / Redwood Sorrel Riparian Forest

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This association is apparently limited to the western Olympic Peninsula, Washington, where it occurs in valley bottoms of major rivers. It is possible that it occurs farther south in coastal Washington or Oregon, though it would be rare there. It is found on fluvial terrace landforms, typically where riverine flooding appears to be currently infrequent (middle to upper terraces). Existing stands most often have a mixed broad-leaved deciduous-needle-leaved evergreen canopy, though some stands are dominated by the deciduous component with few evergreens. The canopy is a variable mixture of Populus balsamifera ssp. trichocarpa (always present in tallest layer), Picea sitchensis (always present), Acer macrophyllum, and in smaller amounts Alnus rubra. Understory trees are mostly Picea sitchensis. The understory is characterized by the constant presence and typical abundance of the forb Oxalis oregana. The deciduous broad-leaved shrub layer varies from sparse to well-developed and is typified by Rubus spectabilis and Acer circinatum. Other herbs that have high constancy and are often codominant are Tolmiea menziesii, Polystichum munitum, and Circaea alpina. Stachys chamissonis var. cooleyae, Mitella ovalis, Athyrium filix-femina, Carex deweyana, Poa trivialis, and Ranunculus repens (latter two non-native) are typically present. The association should be distinguishable by the prominence of Populus balsamifera ssp. trichocarpa in the upper canopy, and >10% cover of Picea sitchensis and >5% cover of Oxalis oregana.

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: No Data Available

Dynamics:  No Data Available

Environmental Description:  No Data Available

Geographic Range: This type may occur only on the western Olympic Peninsula. It is possible in southwest Washington or northwest Oregon.

Nations: US

States/Provinces:  OR?, WA




Confidence Level: Low

Confidence Level Comments: No Data Available

Grank: G2G3

Greasons: No Data Available


Concept Lineage: included here

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: = Picea sitchensis-Acer macrophyllum-Populus trichocarpa community (Fonda 1974)
= Populus balsamifera ssp. trichocarpa-Picea sitchensis-(Acer macrophyllum)/Oxalis oregana Forest (Crawford et al. 2009)
= Populus balsamifera ssp. trichocarpa-Picea sitchensis-Acer macrophyllum/Rubus spectabilis forest (Chappell 1999)

Concept Author(s): C.B. Chappell

Author of Description: C.B. Chappell

Acknowledgements: No Data Available

Version Date: 10-17-02

  • Chappell, C. B. 1999. Ecological classification of low-elevation riparian vegetation on the Olympic Experimental State Forest: A first approximation. Unpublished progress report. Washing Natural Heritage Program, Washington Department of Natural Resources, Olympia. 43 pp.
  • Crawford, R. C., C. B. Chappell, C. C. Thompson, and F. J. Rocchio. 2009. Vegetation classification of Mount Rainier, North Cascades, and Olympic national parks. Plant association descriptions and identification keys: Appendices A-G. Natural Resource Technical Report NPS/NCCN/NRTR--2009/D-586. National Park Service, Fort Collins, CO. 586 pp.
  • Fonda, R. W. 1974. Forest succession in relation to river terrace development in Olympic National Park, Washington. Ecology 55:927-942.
  • WNHP [Washington Natural Heritage Program]. 2018. Unpublished data files. Washington Natural Heritage Program, Department of Natural Resources, Olympia, WA.
  • Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.