Print Report
A3369 Abies concolor Southern Rocky Mountain Mesic Forest & Woodland Alliance
Type Concept Sentence: Forests and woodlands included in this alliance consist of stands dominated by Abies concolor or codominated by Populus tremuloides or Pseudotsuga menziesii. They occur in mountain environments from the southern and central Rocky Mountains and east to the Wyoming Basins.
Common (Translated Scientific) Name: White Fir Southern Rocky Mountain Mesic Forest & Woodland Alliance
Colloquial Name: Southern Rocky Mountain Mesic White Fir Forest & Woodland
Hierarchy Level: Alliance
Type Concept: Forests and woodlands included in this alliance consist of stands dominated by Abies concolor or codominated by Populus tremuloides or Pseudotsuga menziesii. They occur in mountain environments from the southern and central Rocky Mountains and east to the Wyoming basins. In general, these mixed conifer forests have a moderately dense to closed canopy (>60%) with Abies concolor successfully reproducing and typically codominant in the tree canopy. The most common codominant canopy species include Populus tremuloides or Pseudotsuga menziesii. Occasionally these stands occur as woodlands with as little as 10% total canopy cover. Other common canopy associates include Picea pungens, Pinus flexilis, Pinus ponderosa, and Pinus strobiformis. Understories may be shrub-, forb- or graminoid-dominated. The most common dominant shrubs include Acer glabrum, Acer grandidentatum, Holodiscus dumosus, Jamesia americana, Juglans major, Physocarpus malvaceus, Quercus gambelii, and Symphoricarpos oreophilus. Common herbaceous dominants include Erigeron eximius, Lathyrus lanszwertii var. leucanthus, Osmorhiza berteroi, Poa pratensis, and Thalictrum fendleri. These forests occupy a variety of topo-edaphic positions, such as lower and middle slopes of ravines, upper slopes at higher elevations, along stream terraces, ridgetops, and north- and east-facing slopes that burn somewhat infrequently. Parent materials and soils are highly variable and nondefinitive for these forests. Elevations range from 1800-3000 m.
Diagnostic Characteristics: Nearly sparse to dense forests and woodlands where Abies concolor is the primary dominant or codominant with Populus tremuloides or Pseudotsuga menziesii. Indicative of this alliance are understories where Abies concolor is always regenerating. It is distinguished from other Abies concolor alliances in having understories dominated by mesophytic species.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: The former Abies concolor Woodland Alliance (A.553) has been included here. The name of the alliance needs to include better diagnostic species, as this alliance has a name very similar to A3420 (G226). For now, a geographic modifier is used to distinguish it.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: These are open to closed, medium-statured to tall (20-50 m in height), multi-storied forests of needle-leaved evergreen trees. Occasionally a subcanopy (10-20 m tall) of broad-leaved evergreen or cold-deciduous trees may be present. Many densely stocked stands may have a somewhat depauperate understory, but more open stands often have a well-developed ericaceous or cold-deciduous shrub layer. The herbaceous layer is usually dominated by shade-tolerant forbs, but sod-forming or cespitose graminoids may also be common.
Floristics: Forests and woodlands included in this alliance consist of open to closed, medium-statured to tall (20-50 m in height) stands dominated by Abies concolor or codominated by Populus tremuloides or Pseudotsuga menziesii. Occasionally these stands occur as woodlands with as little as 10% total canopy cover. Other common canopy associates include Picea pungens, Pinus flexilis, Pinus ponderosa, and Pinus strobiformis. Understories may be shrub-, forb- or graminoid-dominated. The most common dominant shrubs include Acer glabrum, Acer grandidentatum, Holodiscus dumosus, Jamesia americana, Juglans major, Physocarpus malvaceus, Quercus gambelii, and Symphoricarpos oreophilus. Other shrub associates may include Alnus incana, Amelanchier utahensis, Cornus sericea (= Cornus stolonifera), Juniperus communis, Lonicera arizonica, Lonicera involucrata, Mahonia repens (= Berberis repens), Paxistima myrsinites, Rosa woodsii, Rubus idaeus, and Rubus parviflorus. The herbaceous layer may be quite lush and diverse with shade-tolerant species. Common herbaceous dominants include Erigeron eximius, Lathyrus lanszwertii var. leucanthus, Osmorhiza berteroi, Poa pratensis, and Thalictrum fendleri. Other herbaceous associates may include Aquilegia chrysantha, Artemisia franserioides, Bromus ciliatus var. ciliatus, Bromus ciliatus var. richardsonii (= Bromus richardsonii), Carex siccata (= Carex foenea), Fragaria ssp., Galium mexicanum ssp. asperrimum (= Galium asperrimum), Geranium richardsonii, Koeleria macrantha, Monarda fistulosa var. menthifolia, Oreochrysum parryi, and Osmorhiza depauperata.
Dynamics: With fire suppression, Abies concolor has vigorously colonized many sites which were formerly occupied by open Pinus ponderosa woodlands. These invasions have dramatically changed the fuel load and potential behavior of fire in these forests. In particular, the potential for high-intensity crown fires has increased. Abies concolor is much more shade-tolerant than Populus tremuloides and is the most important regenerating species under closed-canopy conditions. Most of these mixed stands are seral and will eventually be dominated by Abies concolor. This unique forest alliance is linked to gap-forming disturbances, such as fire or windthrow, which allow regeneration of Populus tremuloides and control abundances of Abies concolor (Mueggler and Campbell 1986, Mueggler 1988).
Environmental Description: These forests and woodlands occupy a variety of topo-edaphic positions, such as lower and middle slopes of ravines, upper slopes at higher elevations, canyon sideslopes, along stream terraces, ridgetops, scree slopes and north- and east-facing slopes that burn somewhat infrequently. Parent materials and soils are highly variable and nondefinitive for these forests. Annual precipitation averages 50-80 cm, with abundant snowfall, but summer rainfall due to convective storms is also important. Soils are generally slightly acidic, well-drained loams or sandy loams with substantial organic matter. Elevations range from 1800-3000 m.
Geographic Range: This forest alliance occurs mainly in the southern and central Rocky Mountains, but extends west to the Utah Plateaus, south to the Apache Highlands and west into the Wyoming Basins.
Nations: MX?,US
States/Provinces: AZ, CA?, CO, NM, NV, UT, WY
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899493
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
Concept Lineage: A.152, A.419, A.553, in parts [covers proto-alliances A2101 & A2112].
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: >< Abies concolor Series (Johnston 1987)
>< Interior Douglas-fir: 210 (Eyre 1980) [southwestern stands]
>< Western Needleleaf Forests: 20: Spruce-Fir-Douglas fir Forest (Picea-Abies-Pseudotsuga) (Küchler 1964)
>< Western Needleleaf Forests: 5: Mixed Conifer Forest (Abies-Pinus-Pseudotsuga) (Küchler 1964)
>< White Fir: 211 (Eyre 1980)
>< Interior Douglas-fir: 210 (Eyre 1980) [southwestern stands]
>< Western Needleleaf Forests: 20: Spruce-Fir-Douglas fir Forest (Picea-Abies-Pseudotsuga) (Küchler 1964)
>< Western Needleleaf Forests: 5: Mixed Conifer Forest (Abies-Pinus-Pseudotsuga) (Küchler 1964)
>< White Fir: 211 (Eyre 1980)
- Eyre, F. H., editor. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 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.
- Johnston, B. C. 1987. Plant associations of Region Two: Potential plant communities of Wyoming, South Dakota, Nebraska, Colorado, and Kansas. R2-ECOL-87-2. USDA Forest Service, Rocky Mountain Region. Lakewood, CO. 429 pp.
- Küchler, A. W. 1964. Potential natural vegetation of the conterminous United States. American Geographic Society Special Publication 36. New York, NY. 116 pp.
- Mueggler, W. F. 1988. Aspen community types of the Intermountain Region. General Technical Report INT-250. USDA Forest Service, Intermountain Research Station, Ogden, UT. 135 pp.
- Mueggler, W. F., and R. B. Campbell, Jr. 1986. Aspen community types of Utah. Research Paper INT-362. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT.