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CEGL000296 Abies lasiocarpa - Picea engelmannii / Alnus incana Swamp Forest

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Subalpine Fir - Engelmann Spruce / Gray Alder Swamp Forest

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This spruce-fir riparian forest occurs in the southern Rocky Mountains in Colorado. It occurs on heavily forested reaches of first- and second-order streams above 2440 m (8000 feet) in elevation where Abies lasiocarpa - Picea engelmannii forests also occur on adjacent hillslopes. It is found on stream benches and banks in narrow, V-shaped valleys most commonly within 4.6-6.1 m (15-20 feet) of the channel edge and rarely more than 0.6 m (2 feet) above the streambank. Stream channels vary in their morphology; they can be narrow to wide and steep to flat and sinuous. Soils are shallow, dark-colored layers of loamy sands, silty loams, and sandy clay loams over cobbly alluvium with high organic matter content in the top 50.8 cm (20 inches) and mottles at 101.6 cm (40 inches). Stands have an evergreen needle-leaved tree canopy dominated by Abies lasiocarpa and Picea engelmannii. Occasional canopy associates can include Picea pungens, Pinus contorta, or Populus tremuloides. Tall Alnus incana and Salix drummondiana grow in a thick band along the edge of the stream. At lower elevations, Alnus incana is more abundant than Salix drummondiana. At mid elevations, the two shrubs can be codominant. At higher elevations, Salix drummondiana becomes dominant and Alnus incana drops out, forming ~Abies lasiocarpa - Picea engelmannii / Salix drummondiana Swamp Forest (CEGL000327)$$. In stands where Alnus incana and Salix drummondiana codominate the shrub layer, the stand should be classified as CEGL000327. Additional tall shrubs that can occur in this association include Cornus sericea, Salix geyeriana, Salix monticola, Lonicera involucrata, and Acer glabrum. The herbaceous layer is usually rich in forb species, with total herb cover ranging from 20-70%. Species often include Corydalis caseana ssp. brandegeei, Heracleum maximum, Oxypolis fendleri, Mertensia ciliata, Mertensia franciscana, Maianthemum racemosum ssp. amplexicaule, Streptopus amplexifolius, Pyrola asarifolia, Cardamine cordifolia, Hydrophyllum fendleri, among many others. Graminoids commonly include Calamagrostis canadensis, Carex aquatilis, Glyceria striata, Elymus glaucus, Carex disperma, and Bromus ciliatus. Bryophyte cover is often moderate.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: The Abies lasiocarpa - Picea engelmannii / Alnus incana ssp. tenuifolia - Salix drummondiana (after Baker 1989b) plant association has been split into two plant associations: ~Abies lasiocarpa - Picea engelmannii / Alnus incana Swamp Forest (CEGL000296)$$, which occurs at lower elevations and has Alnus incana in the understory; and ~Abies lasiocarpa - Picea engelmannii / Salix drummondiana Swamp Forest (CEGL000327)$$, which occurs at higher elevations and has very little to no Alnus incana in the understory (Kittel et al. 1996). Stands with both Alnus incana and Salix drummondiana appear to be transitional between these two plant associations. In stands where Alnus incana and Salix drummondiana codominate the shrub layer, the stand should be classified as CEGL000327. Salix drummondiana is a later-successional species and tends to form relatively stable, long-lived seral communities, whereas Alnus incana is a long-lived but early-successional species (Uchytil 1989, 1991a).

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

Floristics: Stands have an evergreen needle-leaved tree canopy dominated by Abies lasiocarpa and Picea engelmannii. Occasional canopy associates can include Picea pungens, Pinus contorta, or Populus tremuloides. Tall Alnus incana and Salix drummondiana grow in a thick band along the edge of the stream. At lower elevations, Alnus incana is more abundant than Salix drummondiana. At mid elevations, the two shrubs can be codominant. At higher elevations, Salix drummondiana becomes dominant and Alnus incana drops out, forming ~Abies lasiocarpa - Picea engelmannii / Salix drummondiana Swamp Forest (CEGL000327)$$. Additional tall shrubs that can occur in this association include Cornus sericea, Salix geyeriana, Salix monticola, Lonicera involucrata, and Acer glabrum. The herbaceous layer is usually rich in forb species, with total herb cover ranging from 20-70%. Species often include Corydalis caseana ssp. brandegeei, Heracleum maximum, Oxypolis fendleri, Mertensia ciliata, Mertensia franciscana, Maianthemum racemosum ssp. amplexicaule, Streptopus amplexifolius, Pyrola asarifolia, Cardamine cordifolia, Hydrophyllum fendleri, among many others. Graminoids commonly include Calamagrostis canadensis, Carex aquatilis, Glyceria striata, Elymus glaucus, Carex disperma, and Bromus ciliatus. Bryophyte cover is often moderate.

Dynamics:  This is a late-seral, or at least long-lived, riparian community. At lower elevations it may represent a successional change from deciduous-dominated overstory to conifer-dominated overstory, a shift that may be attributed to a lack of flooding or other frequent disturbance. The successional process of spruce-fir forests is slow (200+ years); factors such as fire frequency, wind-throw and insect outbreaks affect species composition and age structure of these stands.
Environmental Description:  This spruce-fir riparian forest occurs on heavily forested reaches of first- and second-order streams above 2440 m (8000 feet) in elevation where Abies lasiocarpa - Picea engelmannii forests also occur on adjacent hillslopes. It is found on stream benches and banks in narrow, V-shaped valleys most commonly within 4.6-6.1 m (15-20 feet) of the channel edge and rarely more than 0.6 m (2 feet) above the streambank. Stream channels vary in their morphology; they can be narrow to wide and steep to flat and sinuous. Soils are shallow, dark-colored layers of loamy sands, silty loams, and sandy clay loams over cobbly alluvium with high organic matter content in the top 50.8 cm (20 inches) and mottles at 101.6 cm (40 inches).
Geographic Range: This plant association occurs in Nevada (Manning and Padgett 1995), Utah (Padgett et al. 1989), eastern Idaho, western Wyoming (Youngblood et al. 1985a), and the southern Rocky Mountains in Colorado (CNHP 1997). In Colorado, this association occurs in the Yampa, San Miguel/Dolores (Kittel and Lederer 1993), Gunnison (Kittel et al. 1995), Colorado (Kittel et al. 1994), and South Platte river basins (Kittel et al. 1996), the San Juan, Rio Grande and Routt national forests (Kettler and McMullen 1996, Richard et al. 1996), and Rocky Mountain National Park (Baker 1989b).

Nations: US

States/Provinces:  CO, ID, NV, UT, WY


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: G5

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.Nc Rocky Mountain-Great Basin Montane Flooded & Swamp Forest Division D195 1.B.3.Nc
Macrogroup 1.B.3.Nc.1 Engelmann Spruce - Narrowleaf Cottonwood / Red-osier Dogwood Riparian & Swamp Forest Macrogroup M034 1.B.3.Nc.1
Group 1.B.3.Nc.1.a Engelmann Spruce - Blue Spruce - Narrowleaf Cottonwood Riparian & Swamp Forest Group G506 1.B.3.Nc.1.a
Alliance A3757 Subalpine Fir - Engelmann Spruce Swamp Forest Alliance A3757 1.B.3.Nc.1.a
Association CEGL000296 Subalpine Fir - Engelmann Spruce / Gray Alder Swamp Forest CEGL000296 1.B.3.Nc.1.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Abies lasiocarpa - Picea engelmannii / Alnus incana ssp. tenuifolia Forest (Carsey et al. 2003a)
< Abies lasiocarpa-Picea engelmannii/Alnus incana ssp. tenuifolia-Salix drummondiana (Baker 1989b)
= Abies lasiocarpa-Picea engelmannii/Alnus incana ssp. tenuifolia-Lonicera involucrata-Salix drummondiana (Richard et al. 1996)
= Abies lasiocarpa-Picea engelmannii/Alnus incana ssp. tenuifolia-Lonicera involucrata-Salix drummondiana (Kettler and McMullen 1996)
= Abies lasiocarpa-Picea engelmannii/Alnus incana ssp. tenuifolia-Lonicera involucrata-Salix drummondiana (Baker 1989b)
= Abies lasiocarpa/Alnus incana-Salix drummondiana (Kittel and Lederer 1993)
= Picea engelmannii-Abies lasiocarpa/Alnus incana (Kittel et al. 1994)
= Picea engelmannii-Abies lasiocarpa/Alnus incana (Kittel et al. 1995)
= Subalpine fir-Engelmann spruce /thinleaf alder (Abies lasiocarpa-Picea engelmannii /Alnus incana ssp. tenuifolia) Plant Association (Kittel et al. 1999a)
Concept Author(s): Western Ecology Group

Author of Description: S.L. Neid

Acknowledgements: No Data Available

Version Date: 07-13-05
  • Baker, W. L. 1986a. Riparian vegetation of the montane and subalpine zones in west-central and southwestern Colorado: Final report prepared for The Nature Conservancy and Colorado Natural Areas Program, Boulder.
  • Baker, W. L. 1989b. Classification of the riparian vegetation of the montane and subalpine zones in western Colorado. Great Basin Naturalist 49(2):214-228.
  • Bourgeron, P. S., and L. D. Engelking, editors. 1994. A preliminary vegetation classification of the western United States. Unpublished report. The Nature Conservancy, Western Heritage Task Force, Boulder, CO. 175 pp. plus appendix.
  • CNHP [Colorado Natural Heritage Program]. 2006-2017. Tracked natural plant communities. Colorado Natural Heritage Program, Colorado State University, Fort Collins. [https://cnhp.colostate.edu/ourdata/trackinglist/plant_communities/]
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  • Kettler, S., and A. McMullen. 1996. Routt National Forest riparian vegetation classification. Report prepared for Routt National Forest by the Colorado Natural Heritage Program, Colorado State University, Fort Collins.
  • Kittel, G. M., and N. D. Lederer. 1993. A preliminary classification of the riparian vegetation of the Yampa and San Miguel/Dolores river basins. Unpublished report prepared for Colorado Department of Health and the Environmental Protection Agency by The Nature Conservancy, Colorado Field Office, Boulder.
  • Kittel, G., E. Van Wie, M. Damm, R. Rondeau, S. Kettler, and J. Sanderson. 1999a. A classification of the riparian plant associations of the Rio Grande and Closed Basin watersheds, Colorado. Unpublished report prepared by the Colorado Natural Heritage Program, Colorado State University, Fort Collins.
  • Kittel, G., R. Rondeau, N. Lederer, and D. Randolph. 1994. A classification of the riparian vegetation of the White and Colorado River basins, Colorado. Final report submitted to Colorado Department of Natural Resources and the Environmental Protection Agency. Colorado Natural Heritage Program, Boulder. 166 pp.
  • Kittel, G., R. Rondeau, and A. McMullen. 1996. A classification of the riparian vegetation of the Lower South Platte and parts of the Upper Arkansas River basins, Colorado. Submitted to Colorado Department of Natural Resources and the Environmental Protection Agency, Region VIII. Prepared by Colorado Natural Heritage Program, Fort Collins. 243 pp.
  • Kittel, G., R. Rondeau, and S. Kettler. 1995. A classification of the riparian vegetation of the Gunnison River Basin, Colorado. Submitted to Colorado Department of Natural Resources and the Environmental Protection Agency. Prepared by Colorado Natural Heritage Program, Fort Collins. 114 pp.
  • Manning, M. E., and W. G. Padgett. 1995. Riparian community type classification for Humboldt and Toiyabe national forests, Nevada and eastern California. USDA Forest Service, Intermountain Region. 306 pp.
  • Padgett, W. G., A. P. Youngblood, and A. H. Winward. 1989. Riparian community type classification of Utah and southeastern Idaho. Research Paper R4-ECOL-89-0. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT.
  • Richard, C., G. Kittel, and S. Kettler. 1996. A classification of the riparian vegetation of the San Juan National Forest. Draft 1 report. Colorado Natural Heritage Program, Colorado State University, Fort Collins.
  • Salas, D., J. Stevens, and K. Schulz. 2005. USGS-NPS Vegetation Mapping Program: Rocky Mountain National Park, Colorado. Technical Memorandum No. 8260-05-02. USDI Bureau of Reclamation, Denver, CO. 161 pp. plus Appendices A-L (733 pp.).
  • Uchytil, R. J. 1989. Alnus incana ssp. tenuifolia. In: Fire Effects Information System [Online]. USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). [http://www.fs.fed.us/database/feis/] (accessed 7 March 2005).
  • Uchytil, R. J. 1991a. Salix drummondiana. In: Fire Effects Information System [Online]. USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). [http://www.fs.fed.us/database/feis/] (accessed 7 March 2005).
  • WNDD [Wyoming Natural Diversity Database]. No date. Unpublished data on file. Wyoming Natural Diversity Database, University of Wyoming, Laramie, WY.
  • Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.
  • Youngblood, A. P., W. G. Padgett, and A. H. Winward. 1985a. Riparian community type classification of eastern Idaho-western Wyoming. R4-Ecol-85-01. USDA Forest Service, Intermountain Region, Ogden, UT. 78 pp.