Print Report

CEGL002628 Alnus incana / Athyrium filix-femina Wet Shrubland

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Gray Alder / Common Ladyfern Wet Shrubland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This association is a locally common association found at low elevations from about 701 to 2074 m (2300-6800 feet), in cool and moist, often maritime-influenced, regions of Idaho, Washington, Oregon, and adjacent non-coastal areas. This association often occurs on floodplains, streambanks, and overflow channels of perennial streams that vary in gradient and valley width. These sites usually have soil ranging from silty loam to sandy-gravelly loam over cobble alluvium. The association is also sometimes sampled in wetlands with organic loam soils on the margins of springs, oxbows, lakes, and sediment-filled beaver ponds. Alnus incana forms an open to partially closed canopy, averaging 5-6.5 m tall, typically having 30-60% cover. Picea engelmannii, or Thuja plicata in maritime-influenced areas, occur with moderate constancy, possibly indicating successional pathways for this type. Other shrubs with high constancy, but mostly low cover, include Cornus sericea, Ribes lacustre, Ribes hudsonianum, Rubus parviflorus, and Symphoricarpos albus. Athyrium filix-femina with 20-75% cover, sometimes with lesser amounts of Gymnocarpium dryopteris, forms a lush fern layer, up to 1.0 m tall. Cinna latifolia up to about 20% cover, with less abundant Carex deweyana, Carex disperma, Glyceria striata, and Scirpus microcarpus, are the most common graminoids. Tall forbs, such as Maianthemum stellatum, Mertensia paniculata, Senecio triangularis, and Streptopus amplexifolius, frequently occur with low cover, and a low-forb ground layer (composed of species such as Boykinia major, Circaea alpina, Claytonia cordifolia, Equisetum arvense, Mitella pentandra, and Trautvetteria caroliniensis) also exists.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This association is defined as a PNV vegetation type. If it were renamed as a dominance type the species would include Alnus incana (ALIN), RIHU, and/or COST. This is a well-documented association described from 40 quantitative plots. Twelve in eastern Oregon (Crowe and Clausnitzer 1997, Crowe et al. 2002); and 28 from eastern Washington (Kovalchik 2001). This association may have been included in a broader Alnus incana type in Montana (Hansen et al. 1995). The broad Alnus incana community type of Hansen et al. (1995) has a similar mixed shrub and mesic forb understory, including noticeable Athyrium filix-femina cover. This association resembles other Alnus incana associations which all have similar mixed shrub species, mesic forbs species, and Athyrium filix-femina in their understories (Crowe and Clausnitzer 1997, Kovalchik 2001, Crowe et al. 2002). This association is distinguished from other Alnus incana types in having Athyrium filix-femina as clearly the most abundant understory herbaceous species (with at least, but usually much more than, 5% cover), as well as relatively low cover of other shrub species.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: Alnus incana forms an open to partially closed canopy, averaging 5-6.5 m tall, typically having 30-60% cover. Picea engelmannii, or Thuja plicata in maritime-influenced areas, occur with moderate constancy, possibly indicating successional pathways for this type. Other shrubs with high constancy, but mostly low cover, include Cornus sericea, Ribes lacustre, Ribes hudsonianum, Rubus parviflorus, and Symphoricarpos albus. Athyrium filix-femina with 20-75% cover, sometimes with lesser amounts of Gymnocarpium dryopteris, forms a lush fern layer, up to 1.0 m tall. Cinna latifolia up to about 20% cover, with less abundant Carex deweyana, Carex disperma, Glyceria striata, and Scirpus microcarpus, are the most common graminoids. Tall forbs, such as Maianthemum stellatum, Mertensia paniculata, Senecio triangularis, and Streptopus amplexifolius, frequently occur with low cover, and a low-forb ground layer (composed of species such as Boykinia major, Circaea alpina, Claytonia cordifolia, Equisetum arvense, Mitella pentandra, and Trautvetteria caroliniensis) also exists.

Dynamics:  Overgrazing and trampling decrease Alnus incana vigor and cover. This can reduce its ability to stabilize streambanks, allowing overwidening or incision of the channel, and thus, drying the moist soils necessary to support this association (Crowe and Clausnitzer 1997, Kovalchik 2001). It is most likely a persistent mid-seral type requiring regular flood scouring and deposition for maintenance (Crowe and Clausnitzer 1997, Kovalchik 2001). For example, both Alnus incana and Athyrium filix-femina are quick to recolonize ground disturbed by fire or flood (scouring and alluvial deposition) and might form a stable community until stream dynamics change. If the stream channel becomes sinuous and entrenched (e.g., Rosgen E channel), Salix species may invade (Crowe and Clausnitzer 1997). More likely, downcutting and floodplain widening may dry out alluvial terraces and allow conifer invasion (Hansen et al. 1995). This change may lead toward an Abies grandis-dominated type in the Blue Mountains (Crowe and Clausnitzer 1997) and a Thuja plicata- or Abies lasiocarpa-dominated type in northern Washington and Idaho (Kovalchik 2001), each with Athyrium filix-femina dominating the undergrowth.
Environmental Description:  This association is a locally common association found at low elevations from about 701 to 2074 m (2300-6800 feet), in cool and moist, often maritime-influenced, regions of Idaho, Washington, Oregon, and adjacent non-coastal areas. This association often occurs on floodplains, streambanks, and overflow channels of perennial streams that vary in gradient and valley width. These sites usually have soil ranging from silty loam to sandy-gravelly loam over cobble alluvium. The association is also sometimes sampled in wetlands with organic loam soils on the margins of springs, oxbows, lakes, and sediment-filled beaver ponds.
Geographic Range: This association is known from Idaho, Washington, and Oregon. It is expected to occur in similar habitats in British Columbia, Montana and California.

Nations: CA?,US

States/Provinces:  BC?, CA?, ID, MT?, OR, WA


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: G3

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.C Shrub & Herb Wetland Subclass S44 2.C
Formation 2.C.4 Temperate to Polar Freshwater Marsh, Wet Meadow & Shrubland Formation F013 2.C.4
Division 2.C.4.Nb Western North American Temperate Freshwater Marsh, Wet Meadow & Shrubland Division D031 2.C.4.Nb
Macrogroup 2.C.4.Nb.5 Sitka Alder - Booth''s Willow / Northwest Territory Sedge Montane Marsh, Wet Meadow & Shrubland Macrogroup M893 2.C.4.Nb.5
Group 2.C.4.Nb.5.d Willow species - Alder species - Water Birch Riparian & Seep Shrubland Group G527 2.C.4.Nb.5.d
Alliance A3771 Gray Alder - Green Alder Wet Shrubland Alliance A3771 2.C.4.Nb.5.d
Association CEGL002628 Gray Alder / Common Ladyfern Wet Shrubland CEGL002628 2.C.4.Nb.5.d
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Alnus incana / Athyrium filix-femina (Crowe and Clausnitzer 1997)
= Alnus incana / Athyrium filix-femina Association (Kovalchik 1993) [(p.118)]
= Alnus incana / Athyrium filix-femina Association (Crowe et al. 2004)
= Alnus incana / Gymnocarpium dryopteris (Crowe and Clausnitzer 1997) [(p. 148) (p.130)]
Concept Author(s): C. Murphy

Author of Description: C. Murphy

Acknowledgements: No Data Available

Version Date: 10-18-02
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