Print Report
A3753 Alnus rubra - Fraxinus latifolia / Lysichiton americanus Swamp Woodland Alliance
Type Concept Sentence: Low-elevation deciduous forests and woodlands generally dominated by Alnus rubra, Fraxinus latifolia, or Populus balsamifera ssp. trichocarpa in poorly drained swamps that are seasonally flooded much of the winter, spring, and early summer.
Common (Translated Scientific) Name: Red Alder - Oregon Ash / American Skunk-cabbage Swamp Woodland Alliance
Colloquial Name: Pacific Northwest Alder - Ash Swamp Woodland
Hierarchy Level: Alliance
Type Concept: This alliance occurs throughout the northern Puget Trough lowlands of Washington and British Columbia and in low-lying valleys of the western Oregon and northern California coasts. Forests are dominated by Alnus rubra, Fraxinus latifolia, or Populus balsamifera ssp. trichocarpa which are well-adapted to wet soil conditions. Overstory cover ranges from 40-80%. The forest undergrowth is usually dominated by a deciduous shrub layer with Rubus spectabilis, Crataegus douglasii, Spiraea douglasii, Symphoricarpos albus, Rosa rubiginosa, or Rubus ursinus. The herbaceous layer may be well-developed. Deciduous swamps typically occur along low-elevation (0-1000 m) valley bottoms, along the upland margins of wetlands, or poorly aerated sections of floodplains. Soils are seasonally flooded by spring snowmelt and/or winter rains, which can last well into early summer.
Diagnostic Characteristics: Mineral soil wetlands dominated by Alnus rubra, Fraxinus latifolia, or Populus balsamifera.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Conifer-dominated and mixed conifer-deciduous swamps are a separate alliance. Deciduous tree-dominated riparian areas are another group. Swamps generally have poorly drained, poorly aerated soils relative to riparian and alluvial soils.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Communities within this alliance have an upper canopy dominated by deciduous hardwood trees that form a diffuse canopy of 40-80% canopy cover. The forest undergrowth is usually dominated by a deciduous shrub layer, with 30-60% shrub canopy cover.
Floristics: Forests are dominated by Alnus rubra, Fraxinus latifolia, or Populus balsamifera ssp. trichocarpa which are well-adapted to wet soil conditions, highly shade-intolerant and form a diffuse canopy. Overstory cover ranges from 40-80%. The forest undergrowth is usually dominated by a deciduous shrub layer in which Rubus spectabilis can be the only species (30-60%). Other shrub species are not common, but when present may include Crataegus douglasii, Spiraea douglasii, Symphoricarpos albus, Rosa rubiginosa (= Rosa eglanteria), and Rubus ursinus. The herbaceous layer may be well-developed, with species such as Athyrium filix-femina, Equisetum hyemale, Galium trifidum, Lonicera involucrata, Lysichiton americanus, Rubus ursinus, Tiarella trifoliata, and Tolmiea menziesii. Graminoids include Carex obnupta, Carex deweyana, Carex unilateralis, Carex ovalis (= Carex leporina), and Eleocharis acicularis. Common forbs include Galium trifidum, Galium aparine, Ranunculus uncinatus, Veronica spp., and Geum macrophyllum.
Dynamics: These forests are seasonally flooded by spring snowmelt and rains, and the soils may be saturated year-round in some stands.
Environmental Description: This alliance typically occurs along low-elevation (0-1000 m) streams or valley bottoms, along the upland margins of wetlands, or on the floodplains of streams and rivers. Soils range from alluvium to veneers of muck and peat. Soils are saturated year-round and are composed of muck or peat, silts or clays with poor drainage, and gleying is often evident. Scour and active flooding are not features of these saturated woody wetlands. If this alliance is found on the active floodplains, it occurs around oxbow lakes, swales and other backwater/slackwater areas, and less frequently found along the active streambanks.
Geographic Range: This alliance occurs throughout the northern Puget Trough lowlands of Washington and British Columbia and in low-lying valleys of the western Oregon and northern California coasts.
Nations: CA,US
States/Provinces: BC, OR, WA
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899805
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
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.3 Temperate Flooded & Swamp Forest Formation | F026 | 1.B.3 |
| Division | 1.B.3.Ng Vancouverian Flooded & Swamp Forest Division | D193 | 1.B.3.Ng |
| Macrogroup | 1.B.3.Ng.1 Vancouverian Flooded & Swamp Forest Macrogroup | M035 | 1.B.3.Ng.1 |
| Group | 1.B.3.Ng.1.e Western Hemlock - Red Alder / Yellow Skunk-cabbage Swamp Forest Group | G853 | 1.B.3.Ng.1.e |
| Alliance | A3753 Red Alder - Oregon Ash / American Skunk-cabbage Swamp Woodland Alliance | A3753 | 1.B.3.Ng.1.e |
| Association | CEGL003388 Red Alder / Common Ladyfern - Yellow Skunk-cabbage Swamp Forest | CEGL003388 | 1.B.3.Ng.1.e |
Concept Lineage: A.NCCN-002
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: >< Red Alder Series (Sawyer and Keeler-Wolf 1995)
- Douglas, G. W. 1971. An ecological survey of potential natural areas in the North Cascades National Park complex. Unpublished report prepared for Intercampus Education and Science Preserves Commission, State of Washington. 137 pp.
- Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
- Franklin, J. F., W. H. Moir, M. A. Hemstrom, S. E. Greene, and B. G. Smith. 1988. The forest communities of Mount Rainier National Park. USDI National Park Service. Scientific Monograph Series 19. Washington, DC. 194 pp.
- Franklin, J. F., W. H. Moir, M. A. Hemstrom, and S. Greene. 1979. Forest ecosystems of Mount Rainier National Park. Unpublished report prepared for the USDI National Park Service.
- Henderson, J. A. 1970. Biomass and composition of the understory vegetation in some Alnus rubra stands in western Oregon. Unpublished thesis, Oregon State University, Corvallis, OR. 64 pp.
- Henderson, J. A. 1978. Plant succession on the Alnus rubra / Rubus spectabilis habitat type in western Oregon. Northwest Science 52:(3):156-167.
- Kunze, L. M. 1994. Preliminary classification of native, low elevation, freshwater wetland vegetation in western Washington. Washington State Department of Natural Resources, Natural Heritage Program. 120 pp.
- Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.