Print Report
A3385 Alnus rubra - Acer macrophyllum Forest Alliance
Type Concept Sentence: This alliance consists of communities strongly dominated by Acer macrophyllum and/or Alnus rubra. Some conifers may be present but these have less than 25% relative cover. Vegetation within this alliance usually occurs along low-elevation (0-1000 m) valley slopes and lower mountain slopes of the Pacific Northwest and is often considered an early-seral type to conifer-dominated forests.
Common (Translated Scientific) Name: Red Alder - Bigleaf Maple Forest Alliance
Colloquial Name: Red Alder - Bigleaf Maple Forest
Hierarchy Level: Alliance
Type Concept: This alliance contains communities dominated by Acer macrophyllum and/or Alnus rubra. Some conifers, such as Abies grandis, Picea sitchensis, Pseudotsuga menziesii, Thuja plicata, or Tsuga heterophylla may be present, and can usually be found growing in the understory or as occasional canopy trees, but never have more than 25% relative cover. Other deciduous trees, such as Cornus nuttallii and Betula papyrifera (which is sometimes codominant in northwestern Washington), may also be present in the tree stratum. The forest understory is usually species-rich and well-developed compared to adjacent conifer forests in the same area. Common shrub species in stands of this type include Acer circinatum (which is always present), Gaultheria shallon, Mahonia nervosa, Menziesia ferruginea, Rubus parviflorus, Rubus spectabilis, Sambucus racemosa var. melanocarpa, and Vaccinium membranaceum. The herbaceous layer is often well-developed, with Oxalis oregana and Stachys mexicana particularly common. Ferns can be an abundant component. Species include Polystichum munitum, Athyrium filix-femina, and Pteridium aquilinum. This alliance is found from northwestern British Columbia south along the coastal front and interior valleys to northern California. This maritime-influenced region receives annual precipitation ranging from 75-400 cm, mostly as winter rain. Vegetation within this alliance usually occurs along low-elevation (0-1000 m [0-3300 feet]) valley slopes and lower mountain slopes, often forming a seral community in moist coniferous forests.
Diagnostic Characteristics: Forested stands dominated by Acer macrophyllum and Alnus rubra, singly or in combination.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This alliance is a deciduous tree-dominated alliance. Conifers, if present, are only in the subcanopy or <25% relative cover of the main canopy.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This alliance includes closed-canopy, tall, deciduous forests, usually with a fairly dense shrubby or tall fern-dominated understory. These forests are typically characterized by a broad-leaved deciduous tree canopy from 15-25 m high with over 60% cover. The vigorous shrub layer (2-8 m tall) is dominated by cold-deciduous or evergreen species. The herbaceous understory is typically composed of a diverse and dense mixture of shade-tolerant forbs and ferns.
Floristics: This alliance contains communities dominated by Acer macrophyllum and/or Alnus rubra. Some conifers, such as Abies grandis, Picea sitchensis, Pseudotsuga menziesii, Thuja plicata, or Tsuga heterophylla may be present, and can usually be found growing in the understory or as occasional canopy trees, but never have more than 25% relative cover. Other deciduous trees, such as Cornus nuttallii and Betula papyrifera (which is sometimes codominant in northwestern Washington), may also be present in the tree stratum. The forest understory is usually species-rich and well-developed compared to adjacent conifer forests in the same area. Common shrub species in stands of this type include Acer circinatum (which is always present), Gaultheria shallon, Mahonia nervosa, Menziesia ferruginea, Rubus parviflorus, Rubus spectabilis, Sambucus racemosa var. melanocarpa, and Vaccinium membranaceum. The herbaceous layer is often well-developed, with Oxalis oregana and Stachys mexicana particularly common. Ferns can be an abundant component and include Polystichum munitum, Athyrium filix-femina, and Pteridium aquilinum.
Dynamics: Stands of this alliance are often favored by disturbance. Communities within this alliance are usually seral to conifer forest, but can persist on particularly moist sites. Most of these are forests that initiated following fire, logging, and other stand-replacement disturbances (Chappell et al. 1997). They may be associated with fire, or are steep slope forests associated with landslides and windthrows. Many stands of this alliance are associated with past logging. Alnus rubra is a nitrogen-fixing species which increases local soil fertility after colonization.
Environmental Description: Vegetation within this alliance usually occurs along low-elevation (0-1000 m) valley slopes and lower mountain slopes, often forming a seral community in moist coniferous forests along the Pacific coast from central California north through Oregon and Washington. This maritime-influenced region receives annual precipitation ranging from 75-400 cm, mostly as winter rain.
Geographic Range: This alliance is found from northwestern British Columbia south along the coastal front and interior valleys to northern California.
Nations: CA,US
States/Provinces: BC, CA, OR, WA
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899509
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
Concept Lineage: A.263, A.264 (A.NCCN-020)
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: ? Acer macrophyllum (Bigleaf maple forest) Alliance (Sawyer et al. 2009) [61.450.00]
? Alnus rubra (Red alder forest) Alliance (Sawyer et al. 2009) [61.410.00]
? Alnus rubra (Red alder forest) Alliance (Sawyer et al. 2009) [61.410.00]
- Chappell, C., R. Crawford, J. Kagan, and P. J. Doran. 1997. A vegetation, land use, and habitat classification system for the terrestrial and aquatic ecosystems of Oregon and Washington. Unpublished report prepared for Wildlife habitat and species associations within Oregon and Washington landscapes: Building a common understanding for management. Prepared by Washington and Oregon Natural Heritage Programs, Olympia, WA, and Portland, OR. 177 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.
- Fonda, R. W. 1974. Forest succession in relation to river terrace development in Olympic National Park, Washington. Ecology 55:927-942.
- Franklin, J. F., and C. T. Dyrness. 1969. Vegetation of Oregon and Washington. Research Paper PNW-80. USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Portland, OR. 216 pp.
- Franklin, J. F., and C. T. Dyrness. 1973. Natural vegetation of Oregon and Washington. General Technical Report PNW-8. USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Portland, OR. 417 pp.
- Hemstrom, M. A., and S. E. Logan. 1986. Plant association and management guide Siuslaw National Forest. Report R6-Ecol 220-1986a. USDA Forest Service, Pacific Northwest Region, Portland, OR. 121 pp.
- Henderson, J. A., D. A. Peter, and R. Lesher. 1986. Preliminary plant associations of the Olympic National Forest. USDA Forest Service, Pacific Northwest Region. 136 pp.
- Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.
- del Moral, R., and J. N. Long. 1977. Classification of montane forest community types in the Cedar River drainage of western Washington, U.S.A. Canadian Journal of Forest Research 7(2):217-225.