Print Report
A0586 Cercocarpus ledifolius Shrubby Woodland Alliance
Type Concept Sentence: This woodland is characterized by an open to moderately dense tree canopy of Cercocarpus ledifolius with the understory characterized by an open to moderate shrub layer (>10% cover) or, if less, then shrub cover exceeds herbaceous cover. It occurs in semi-arid steppe and temperate mountainous habitats of the interior western United States.
Common (Translated Scientific) Name: Curl-leaf Mountain-mahogany Shrubby Woodland Alliance
Colloquial Name: Curl-leaf Mountain-mahogany Shrubby Woodland
Hierarchy Level: Alliance
Type Concept: The vegetation in this alliance is characterized by an open to moderately dense canopy of Cercocarpus ledifolius. These woodlands may occur as scattered communities in arid steppe or on rocky outcrops or steep escarpments within forests. Steppe woodlands typically have only Cercocarpus ledifolius in the overstory canopy, but Juniperus occidentalis, Juniperus osteosperma, Juniperus scopulorum, Pinus edulis, or Pinus monophylla occur locally. The understory is characterized by an open to dense short-shrub layer. Shrub cover is over 10% or, if less, exceeds herbaceous cover. Characteristic shrub species include Amelanchier alnifolia, Arctostaphylos patula, Artemisia tridentata, Ericameria nauseosa, Holodiscus dumosus, Prunus virginiana, Purshia tridentata, Quercus gambelii, Ribes spp., Symphoricarpos oreophilus, and Symphoricarpos rotundifolius. Stands with sparse understories are included in this alliance because these stands usually have similar scattered shrubs present. A sparse to moderately dense herbaceous layer may be present and is typically dominated by bunchgrasses, including Achnatherum spp., Calamagrostis rubescens, Elymus elymoides, Festuca idahoensis, Leymus ambiguus, and Pseudoroegneria spicata. Diverse forbs may be present but usually with low cover. Plant associations in this alliance occur in semi-arid steppe and cool temperate mountainous habitats of the interior western United States. These woodlands often form small patchy stands on rocky outcrops or escarpments in forested areas, or may form the only tree cover in steppe regions. Elevations range from 1600 to 2835 m (5250-9300 feet). Annual precipitation averages 25-45 cm, with a significant proportion falling as winter snow. Soils are typically rocky and immature, and of coarser texture than soils of adjacent coniferous woodlands or forests.
Diagnostic Characteristics: The vegetation in this woodland alliance is characterized by a tree canopy dominated by Cercocarpus ledifolius, sometimes with low cover of Juniperus occidentalis, Juniperus osteosperma, Juniperus scopulorum, Pinus edulis, or Pinus monophylla. The understory is characterized by an open to dense shrub layer dominated by species such as Amelanchier alnifolia, Arctostaphylos patula, Artemisia tridentata, Ericameria nauseosa, Holodiscus dumosus, Quercus gambelii, Prunus virginiana, Purshia tridentata, Ribes spp., Symphoricarpos oreophilus, or Symphoricarpos rotundifolius. An herbaceous layer may be present and is typically dominated by bunchgrasses sometimes with low cover of diverse forbs. If shrub cover is low (<10%), then it exceeds herbaceous cover.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: The Cercocarpus ledifolius woodland and shrubland alliances are poorly distinguished in the literature, as most authors describe the species as having either a tall-shrub or small-tree growth form within a single association. Some associations may have shrub-dominated stands in one area and also have a woodland physiognomy in another. The woodland physiognomy appears to be more typical, based on available literature. Near the northern edge of its range in Montana and Idaho, Cercocarpus ledifolius is described as occurring primarily in the shrub-form (Mueggler and Stewart 1980, Tisdale 1986). These northern variants are the only described stands which appear to be clearly distinct from the woodland alliance.
The woodland stands may have a different subspecies (or variety) as a dominant than the shrubland. In Wyoming, the heritage program is proposing to recognize two Cercocarpus ledifolius alliances, based upon varieties of Cercocarpus ledifolius. The most widespread proposed alliance there is dominated by Cercocarpus ledifolius var. ledifolius, which grows up to about 1.5 m tall. The other proposed alliance, dominated by Cercocarpus ledifolius var. intercedens, is found only along the western border of the state, and the growth form is as small trees 4-5 m tall. The two taxa are obviously different in Wyoming, in stature and leaf characteristics, and are easily separated. Further review of the two current Cercocarpus ledifolius alliances may warrant treatment as proposed for Wyoming.
The woodland stands may have a different subspecies (or variety) as a dominant than the shrubland. In Wyoming, the heritage program is proposing to recognize two Cercocarpus ledifolius alliances, based upon varieties of Cercocarpus ledifolius. The most widespread proposed alliance there is dominated by Cercocarpus ledifolius var. ledifolius, which grows up to about 1.5 m tall. The other proposed alliance, dominated by Cercocarpus ledifolius var. intercedens, is found only along the western border of the state, and the growth form is as small trees 4-5 m tall. The two taxa are obviously different in Wyoming, in stature and leaf characteristics, and are easily separated. Further review of the two current Cercocarpus ledifolius alliances may warrant treatment as proposed for Wyoming.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Plant associations in this alliance are woodlands dominated by a spreading broad-leaved evergreen small tree (5-15 m tall) with open to moderate cover (10-60%). Smaller evergreen or cold-deciduous shrubs may be present and are typically of low to medium cover. A ground layer of cespitose or rhizomatous graminoids is usually present, but cover is highly variable.
Floristics: The vegetation in this alliance is characterized by an open to moderately dense canopy of Cercocarpus ledifolius. Steppe woodlands typically have only Cercocarpus ledifolius in the overstory canopy, but Juniperus occidentalis, Juniperus osteosperma, Juniperus scopulorum, Pinus edulis, or Pinus monophylla occur locally. Montane stands may have scattered emergent conifer trees present, including Pinus jeffreyi, Pinus ponderosa, and Pseudotsuga menziesii. The understory is characterized by an open to dense short-shrub layer. Shrub cover is over 10% or, if less, exceeds herbaceous cover. Characteristic shrub species include Amelanchier alnifolia, Arctostaphylos patula, Artemisia tridentata, Ericameria nauseosa (= Chrysothamnus nauseosus), Holodiscus dumosus, Prunus virginiana, Purshia tridentata, Quercus gambelii, Ribes spp., Symphoricarpos oreophilus, Symphoricarpos rotundifolius, and Tetradymia canescens. Stands with sparse understories are included in this alliance because these stands usually have similar scattered shrubs present. A sparse to moderately dense herbaceous layer may be present and is typically dominated by bunchgrasses, including Achnatherum spp., Calamagrostis rubescens, Elymus elymoides, Festuca idahoensis, Leymus ambiguus, and Pseudoroegneria spicata. Diverse forbs may be present but usually with low cover. Common forbs include Arenaria spp., Balsamorhiza sagittata, Chaetopappa ericoides, Comandra umbellata, Hackelia patens, Lappula occidentalis, Packera multilobata (= Senecio multilobatus), and Senecio integerrimus.
Dynamics: Cercocarpus ledifolius is a slow-growing, drought-tolerant species that can inhabit very poor sites, such as cliffs and outcrops. Stands are often small and clumped near ridgetops. These sites may also afford the species some protection from fire. The species is highly susceptible to fire damage and generally does not resprout. Cercocarpus ledifolius is highly favored by native ungulates for winter range, and many individual shrubs show evidence of highlining by deer or elk.
Environmental Description: Plant associations in this woodland alliance occur in semi-arid steppe and foothills, and cool temperate mountainous habitats of the interior western United States. These woodlands often form small patchy stands in arid steppe or on rocky outcrops or steep escarpments in forested areas or may form the only tree cover in steppe regions. Elevations range from 1600 to 2835 m (5250-9300 feet). Climate ranges from semi-arid at lower elevations in the Colorado Plateau, Columbia Plateau, and Owyhee Uplands to cool temperate in foothills and mountains of the western Sierra Nevada, northern Great Basin, and western slope of the Rocky Mountains. Precipitation is variable in amount and season depending on locations, with annual precipitation ranging from 25-45 cm with much of the precipitation falling during the winter months as snow in mountains or as convective showers in May and June in steppe and foothills. Lower elevation sites in steppe regions have rolling topography with low relief. Stands found in foothills and mountains occur on moderate to very steep slopes and ridges. Aspect is variable depending on elevation with cooler east to north slopes more typical of lower elevation sites. Soils are mostly shallow, rocky, well-drained sandy or gravelly loams derived from colluvium, bedrock, or less frequently alluvium. Parent materials are variable and include andesite, basalt, granite, rhyolite, tuff and metamorphic (schist) rocks, and sandstones. Stones make up 30-60% of the soil volume. Cercocarpus roots extend into cracks within the bedrock.
Geographic Range: This alliance occurs in the Great Basin extending west into the foothills of the Sierra Nevada and north into the Columbia Plateau, from northeastern California north across Nevada, into southeastern Oregon, southern Idaho, western Utah and southwestern Montana.
Nations: US
States/Provinces: AZ, CA, CO, ID, MT, NV, OR, UT, WY?
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.857466
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
Concept Lineage: This alliance includes 8 shrub understory associations from Old Alliance II.A.5.N.a. Cercocarpus ledifolius Woodland Alliance (A.586).
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: >< Cercocarpus ledifolius (Curl leaf mountain mahogany scrub) Alliance (Sawyer et al. 2009) [76.200.00]
= Cercocarpus ledifolius Shrubland Alliance (Evens et al. 2014)
= Cercocarpus ledifolius Shrubland Alliance (Evens et al. 2014)
- Blackburn, W. H., P. T. Tueller, and R. E. Eckert, Jr. 1969d. Vegetation and soils of the Pine and Mathews Canyon watersheds. Nevada Agricultural Experiment Station Bulletin R-46. Reno. 111 pp.
- Cooper, S. V., P. Lesica, R. L. DeVelice, and T. McGarvey. 1995. Classification of southwestern Montana plant communities with emphasis on those of Dillon Resource Area, Bureau of Land Management. Montana Natural Heritage Program, Helena, MT. 154 pp.
- DeVelice, R. L. 1992. Classification of the plant communities of Beaverhead, Silver Bow, and Madison counties, Montana. Volume I (text). Prepared for the Montana Natural Heritage Program, Helena, MT. 35 pp.
- Dealy, J. E. 1975. Ecology of curl-leaf mahogany (Cercocarpus ledifolius Nutt.) in Oregon and adjacent areas. Unpublished dissertation, Oregon State University, Corvallis. 168 pp.
- Evens, J. M., K. Sikes, D. Hastings, and J. Ratchford. 2014. Vegetation alliance descriptions for Lake Mead National Recreation Area, Death Valley National Park and Mojave National Preserve. Unpublished report submitted to USDI National Park Service, Mojave Desert Network Inventory and Monitoring Program. California Native Plant Society, Sacramento, CA.
- 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.
- Gruell, G. E., S. Bunting, and L. Neuenschwander. 1985. Influence of fire on curlleaf mountain-mahogany in the Intermountain West. Pages 58-72 in: J. E. Lotan and J. K. Brown, compilers. Fire''s effects on wildlife habitat-symposium proceedings. USDA Forest Service Technical Report INT-186, Intermountain Forest and Range Experiment Station, Ogden, UT.
- Hall, F. C. 1973. Plant communities of the Blue Mountains in eastern Oregon and southeastern Washington. R6 Area Guide 3-1. USDA Forest Service, Pacific Northwest Region, Portland, OR. 62 pp.
- Keeler-Wolf, T., and K. Thomas. 2000. Draft descriptions of vegetation alliances for the Mojave Ecosystem Mapping project. California Natural Diversity Database, California Department of Fish and Game, Sacramento.
- Moseley, R. K. 1987b. Area of Critical Environmental Concern and Research Natural Area proposal for the Malm Gulch and Germer Basin area, Bureau of Land Management, Salmon District, Idaho. Unpublished report prepared for USDI Bureau of Land Management, Salmon District, ID, by The Nature Conservancy, Moscow, ID. 18 pp.
- Mozingo, H. 1987. Shrubs of the Great Basin: A natural history. University of Nevada Press, Las Vegas. 342 pp.
- Mueggler, W. F., and W. L. Stewart. 1980. Grassland and shrubland habitat types of western Montana. General Technical Report INT-66. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT. 154 pp.
- Reid, M. S., K. A. Schulz, P. J. Comer, M. H. Schindel, D. R. Culver, D. A. Sarr, and M. C. Damm. 1999. An alliance level classification of vegetation of the coterminous western United States. Unpublished final report to the University of Idaho Cooperative Fish and Wildlife Research Unit and National Gap Analysis Program, in fulfillment of Cooperative Agreement 1434-HQ-97-AG-01779. The Nature Conservancy, Western Conservation Science Department, Boulder, CO.
- 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.
- Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.
- Tisdale, E. W. 1986. Canyon grasslands and associated shrublands of west-central Idaho and adjacent areas. Bulletin No. 40. Forest, Wildlife and Range Experiment Station, University of Idaho, Moscow. 42 pp.
- VegCAMP and AIS [Vegetation Classification and Mapping Program and Aerial Information Systems, Inc.]. 2013. 2012 California desert vegetation map and accuracy assessment in support of the Desert Renewable Energy Conservation Plan. Unpublished report to California Department of Fish and Wildlife Renewable Energy Program and the California Energy Commission. California Department of Fish and Wildlife, Vegetation Classification and Mapping Program and Aerial Information Systems, Inc.