Common (Translated Scientific) Name: Sitka Spruce / Salmonberry / Slough Sedge - American Skunk-cabbage Swamp Forest

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This association occurs along the Pacific Coast from northern California to British Columbia. It is a wetland type occurring in coastal wetlands, primarily on floodplains adjacent to perennial streams and rivers, but occasionally on depressions between old stabilized dunes. Soils are perennially wet, usually with high organic content. Old-growth stands are rare, because most swamps were readily accessible for logging, and suitable sites were never numerous or extensive. Stands of this type are dominated by Picea sitchensis and Alnus rubra, with Tsuga heterophylla occasionally occurring on mounds. While Picea sitchensis may reach large diameters typical of those growing in upland sites, growth rates in perennially wet soils are slow, and ages of trees often greatly exceed estimates based on familiarity with upland stands. Shallow root systems, buttressed roots, and reduced crown spread are typical of swamp Picea sitchensis individuals. Large wads of Polypodium scouleri and thick mats of epiphytic mosses, particularly Antitrichia curtipendula, are typical on upper trunks and limbs. Canopy cover of Picea sitchensis may be as low as 50%, and high light levels favor a dense growth of Alnus rubra and Rubus spectabilis, with Gaultheria shallon occurring on mounds. The herb layer is a mix of Carex obnupta, Lysichiton americanus, and Athyrium filix-femina, with exposures of often deep, mucky soil between them. Windthrow is frequent and creates gaps for spruce regeneration, often as resprouts from fallen boles. This is a late-seral to climax association, with forests replacing both ~Alnus rubra / Rubus spectabilis / Carex obnupta - Lysichiton americanus Riparian Forest (CEGL003389)$$ and ~Salix hookeriana - (Malus fusca) / Carex obnupta - Lysichiton americanus Wet Shrubland (CEGL003432)$$. Remnant old-growth stands of this association may contain considerable volumes of timber, but should be protected because this association is so rare. Large horizontal limbs and their moss mats may be nesting sites for marbled murrelets. Sites may be vulnerable to catastrophic windthrow, and windfirm buffers could help avert damage in some cases. Some sites are also vulnerable to tsunamis or drowning caused by subsidence following an earthquake. This is the only coastal Picea sitchensis association which has both Carex obnupta and Lysichiton americanus in the understory. Similar types are found further inland, but lack Picea sitchensis.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Since Alnus rubra is always an important part of this wetland association, a better name might be Picea sitchensis - Alnus rubra / Carex obnupta - Lysichiton americanus Saturated Forest. This association may also occur in Alaska.

Similar NVC Types: No Data Available

note: No Data Available