Print Report

A0587 Cercocarpus montanus var. glaber Mesic Chaparral Alliance

Type Concept Sentence: Vegetation in this alliance is characterized by the presence of Cercocarpus montanus var. glaber or Cercocarpus montanus var. minutiflorus as either a tall shrub or small tree. The shrub layer is variable in density and species composition, because of the wide distribution (within California) of the alliance, being known from the valleys of northwestern California to montane habitats in the southern part of the state.

Common (Translated Scientific) Name: Birchleaf Mountain-mahogany Mesic Chaparral Alliance

Colloquial Name: Mesic Birchleaf Mountain-mahogany Chaparral

Hierarchy Level:  Alliance

Type Concept: Vegetation in this alliance is characterized by the presence of Cercocarpus montanus var. glaber or Cercocarpus montanus var. minutiflorus as either a tall shrub or small tree. The shrub layer is variable in density and species composition, because of the wide distribution (within California) of the alliance. Characteristic shrubs include several species of Ceanothus and Arctostaphylos, Adenostoma fasciculatum, Artemisia tridentata, Eriogonum fasciculatum, Eriogonum wrightii, Fremontodendron californicum, Garrya flavescens, Heteromeles arbutifolia, Malosma laurina, Prunus ilicifolia, Quercus berberidifolia, Quercus john-tuckeri, Rhamnus ilicifolia, Salvia apiana, Salvia mellifera, and Hesperoyucca whipplei. Tree associates include many different species of Quercus, Juniperus, and Pinus depending on location, but they usually have scant cover. Most stands are open and typically occupy rockier sites than denser Ceanothus- and Quercus-dominated chaparral types. This alliance is widely distributed latitudinally, known from the valleys of northwestern California to montane habitats in the southern part of the state. Elevation ranges from 100-2400 m. Depending upon local moisture conditions and fire history, this vegetation can occur on ridges with stony, excessively drained soils or moist swales with fine soils and subirrigation. Habitats are ridges and upper slopes on all aspects, and fractured rock outcrops, including limestone and marble, and rarely flooded, rocky alluvium. Soils are shallow, rocky, and well-drained.

Diagnostic Characteristics: Both Cercocarpus montanus and Eriogonum fasciculatum between 30-60% relative cover in the shrub canopy (Gordon and White 1994); Cercocarpus montanus >30% relative cover with no other shrub species exceeding it in cover, or Cercocarpus montanus and Arctostaphylos glauca with equal relative cover (Keeler-Wolf et al. 1998a); or Cercocarpus montanus =30% relative cover, and other chaparral shrubs may be equally important in cover, including Adenostoma fasciculatum and Ceanothus spinosus (Keeler-Wolf and Evens 2006).

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance is dominated by Cercocarpus montanus var. glaber (Kartesz 1999), which is treated as Cercocarpus betuloides by Sawyer and Keeler-Wolf (1995), following the treatment of Hickman (1993). This alliance includes stands dominated by Cercocarpus montanus var. minutiflorus. In some stands along the western desert margins and in inland cismontane California, relatively tall Cercocarpus montanus shrubs share dominance with the relatively low shrub Eriogonum fasciculatum, along with other low shrubs. Such stands of transitional scrub have often been called desert chaparral (Horton 1960) or semi-desert chaparral (Holland 1986b). Stands occupy locally xeric, steep, rocky exposures or occur along intermittently flooded stream channels with well-drained sandy and bouldery substrates. Associations dominated by Cercocarpus montanus vary in the species composition of the secondary species.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Stands are dominated by a long-lived evergreen shrub or small tree which typically forms open woodlands or shrublands of 30-60% cover. Evergreen shrubs are common in the understory, sometimes forming a dense thicket. Herbaceous associates are usually scattered cespitose graminoids.

Floristics: This alliance is widely distributed latitudinally, with many associated species across its range. Perhaps the largest stands of tree-sized Cercocarpus montanus var. glaber occur in the semi-arid interior Klamath/Siskiyou region. In these northern stands, Quercus garryana, Quercus kelloggii, and Juniperus occidentalis are common tree associates. Shrubs are a mixture of steppe and coastal species, including Arctostaphylos spp., Artemisia tridentata, Ceanothus cuneatus, Garrya fremontii, and Purshia tridentata. In central California, the vegetation is usually associated with species from adjacent chaparral or oak-pine woodlands. Common tree species include Aesculus californica, Juniperus californica, Pinus coulteri, Pinus ponderosa, Pinus sabiniana, Quercus chrysolepis, Quercus douglasii, Quercus kelloggii, and Quercus wislizeni. Shrub associates are exceptionally diverse across the range of this alliance. Common and recurrent associates include Adenostoma fasciculatum, Arctostaphylos spp., Ceanothus cuneatus, Ceanothus integerrimus, Ceanothus megacarpus, Ceanothus papillosus, Ceanothus spinosus, Eriogonum fasciculatum, Frangula californica (= Rhamnus californica), Quercus berberidifolia, Quercus garryana var. fruticosa (= var. breweri), and Rhamnus ilicifolia. In San Diego County stands dominated by Cercocarpus montanus var. minutiflorus have been described, and are included in this alliance. Along the interior edges of the Transverse and Peninsular ranges of southern California, these stands often grade into pinyon-juniper woodlands. Common tree associates in these stands include Juniperus californica, Pinus monophylla, Pinus quadrifolia, and Pseudotsuga macrocarpa, occurring with many of the shrub species mentioned above.

Dynamics:  Cercocarpus montanus var. glaber, a long-lived, slow-growing shrub or small tree, composes a significant part of the chaparral vegetation of California and southern Oregon. It attains tree stature only at sites with relatively long fire-return intervals. Habitats such as steppe margins, where vegetation cover is relatively sparse, or rocky outcrops are most favorable for development of these communities.

Cercocarpus montanus is generally top-killed and sprouts vigorously from the root crowns and stumps after most fires; however, seedling establishment may be relatively low and mortality high. Seeds typically germinate in fire-free intervals; seedling establishment is episodic and occurs usually >60 years after fire. Older stands can have a buildup of dead surface fuels, but they are not completely consumed (Uchytil 1991c). Stands that have not burned for many decades develop a woodland character associated with other tall shrubs and trees, but stands with more frequent fire intervals are low, shrubby, and open.
Environmental Description:  This vegetation is widely distributed along the interior margin of the California floristic province of the southern and central Pacific Slope, often at or near the border with transmontane steppe habitats. Precipitation varies from 25 to 90 cm annually, arriving in a Mediterranean pattern of winter surplus and prolonged summer drought. Depending upon local moisture conditions and fire history, this vegetation can occur on ridges with stony, excessively drained soils or moist swales with fine soils and subirrigation.
Geographic Range: This alliance is found throughout California, from the valleys of northwestern California to montane habitats in the southern part of the state.

Nations: MX?,US

States/Provinces:  AZ?, CA, MXBCN?


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: G5

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.B Temperate & Boreal Grassland & Shrubland Subclass S18 2.B
Formation 2.B.1 Mediterranean Scrub & Grassland Formation F038 2.B.1
Division 2.B.1.Na Californian Scrub & Grassland Division D327 2.B.1.Na
Macrogroup 2.B.1.Na.1 Chamise - Whiteleaf Manzanita - Scrub Oak Chaparral Macrogroup M043 2.B.1.Na.1
Group 2.B.1.Na.1.b Scrub Oak - Eastwood''s Manzanita - California Ash Chaparral Group G261 2.B.1.Na.1.b
Alliance A0587 Birchleaf Mountain-mahogany Mesic Chaparral Alliance A0587 2.B.1.Na.1.b
Association CEGL003615 Birchleaf Mountain-mahogany Shrubland CEGL003615 2.B.1.Na.1.b
Association CEGL003621 Birchleaf Mountain-mahogany - Chamise Shrubland CEGL003621 2.B.1.Na.1.b
Association CEGL003630 Birchleaf Mountain-mahogany - Redheart Shrubland CEGL003630 2.B.1.Na.1.b
Association CEGL003633 Birchleaf Mountain-mahogany - Laurel Sumac - Coastal Sagebrush Shrubland CEGL003633 2.B.1.Na.1.b
Association CEGL008638 Birchleaf Mountain-mahogany Sierran Chaparral Shrubland CEGL008638 2.B.1.Na.1.b
Concept Lineage: A.587 is equivalent

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: ? Cercocarpus betuloides (Hickman 1993)
= Cercocarpus minutiflorus Alliance (Sproul et al. 2011)
= Cercocarpus montanus (Birch leaf mountain mahogany chaparral) Alliance (Sawyer et al. 2009) [76.100.00]
= Cercocarpus montanus Shrubland Alliance (CNPS 2017) [76.100.00]
? Birchleaf Mountain-Mahogany Series (Sawyer and Keeler-Wolf 1995)
>< Flannel Bush Chaparral (#37J00) (Holland 1986b)
>< Northern North Slope Chaparral (#37E10) (Holland 1986b)
>< Semi-Desert Chaparral (#37400) (Holland 1986b)
>< Southern North Slope Chaparral (#37E20) (Holland 1986b)
Concept Author(s): M.S. Reid, D. Sarr, and G. Kittel, in Faber-Langendoen et al. (2013)

Author of Description: M.S. Reid

Acknowledgements: No Data Available

Version Date: 12-18-14
  • Barbour, M. G., and J. Major, editors. 1977. Terrestrial vegetation of California. John Wiley and Sons, New York. 1002 pp.
  • Borchert, M., A. Lopez, C. Bauer, and T. Knowd. 2004. Field guide to coastal sage scrub and chaparral series of Los Padres National Forest. Report R5-TP-019. USDA Forest Service, Pacific Southwest Region, San Francisco, CA.
  • CNPS [California Native Plant Society]. 2015-2017. A manual of California vegetation [online]. California Native Plant Society, Sacramento, CA. [http://vegetation.cnps.org/].
  • Cheatham, N. H., and J. R. Haller. 1975. An annotated list of California habitat types. Unpublished report. University of California, Natural Land and Water Reserves System.
  • Cheng, S. 2004. Forest Service research natural areas in California. General Technical Paper PSW-GTR-188. USDA Forest Service, Pacific Southwest Research Station, Albany, CA.
  • Evens, J., A. Klein, J. Taylor, T. Keeler-Wolf, and D. Hickson, principal investigators. 2006. Vegetation classification, descriptions, and mapping of the Clear Creek Management Area, Joaquin Ridge, Monocline Ridge, and Environs in San Benito and western Fresno counties, California. Final report prepared by California Native Plant Society and California Department of Fish and Game, Sacramento, CA. 273 pp.
  • Evens, J., and S. San. 2004. Vegetation associations of a serpentine area: Coyote Ridge, Santa Clara County, California. Unpublished report. California Native Plant Society, Sacramento, CA.
  • Evens, J., and S. San. 2006. Vegetation alliances of the San Dieguito River Park region, San Diego County, California. Final report (August 2005) Version 2 (revised May 2006). Prepared by California Native Plant Society in cooperation with the California Natural Heritage Program of the California Department of Fish and Game and San Diego Chapter of the California Native Plant Society. Sacramento, CA. 271 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.
  • Gordon, H. J., and T. C. White. 1994. Ecological guide to the southern California chaparral plant series. Technical Report R5-ECOL-TP-005. USDA Forest Service, Pacific Southwest Region, San Francisco, CA.
  • Hanes, T. L. 1976. Vegetation types of the San Gabriel Mountains. Pages 65-76 in: J. Latting, editor. Plant communities of southern California. Symposium proceedings. Special Publication No. 2. California Native Plant Society, Sacramento, CA.
  • Hanes, T. L. 1977. Chaparral. Pages 417-469 in: M. G. Barbour and J. Major, editors. Terrestrial vegetation of California. Wiley-Interscience, reprinted 1988 by the California Native Plant Society, Sacramento, CA.
  • Hanes, T. L. 1981. California chaparral. Pages 139-174 in: F. di Castri, D. W. Goodall, and R. L. Specht, editors. Ecosystems of the world 11: Mediterranean-type shrublands. Elsevier Scientific Publishing Company, New York, NY.
  • Hickman, J. C. 1993. The Jepson manual: Higher plants of California. University of California Press, Ltd., Berkeley, CA. 1400 pp.
  • Holland, R. F. 1986b. Preliminary descriptions of the terrestrial natural communities of California. Unpublished report prepared for the California Department of Fish and Game, Nongame-Heritage Program and Natural Diversity Database, Sacramento. 156 pp.
  • Horton, J. S. 1960. Vegetation types of the San Bernardino Mountains. PSW Technical Paper 44. USDA Forest Service, Pacific Southwest Research Station, Berkeley, CA.
  • Kartesz, J. T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: J. T. Kartesz and C. A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, NC.
  • Keeler-Wolf, T., C. Roye, and K. Lewis. 1998a. Vegetation mapping and classification of the Anza-Borrego Desert State Park, California. Unpublished report on file at California Natural Diversity Database, California Department Fish and Game, Sacramento.
  • Keeler-Wolf, T., M. Schindel, S. San, P. Moore, and D. Hickson. 2003a. Classification of the vegetation of Yosemite National Park and surrounding environs in Tuolumne, Mariposa, Madera and Mono counties, California. Unpublished report by NatureServe in cooperation with the California Native Plant Society and California Department of Fish and Game, Wildlife and Habitat Data Analysis Branch, Sacramento, CA.
  • Keeler-Wolf, T., and J. Evens. 2006. Vegetation classification of the Santa Monica Mountains National Recreation Area and environs in Ventura and Los Angeles counties, California. A report submitted to National Park Service, Santa Monica Mountains National Recreation Area by California Department of Fish and Game, Wildlife and Habitat Data Analysis Branch and The California Native Plant Society, Vegetation Program, Sacramento, CA.
  • Keeley, J. E., and S. C. Keeley. 1988. Chaparral. Pages 165-207 in: M. G. Barbour and W. D. Billings, editors. North American terrestrial vegetation. Cambridge University Press, New York, NY.
  • Kittel, G., E. Reyes, J. Evens, J. Buck, and D. Johnson. 2012a. Vegetation classification and mapping project report, Pinnacles National Monument. Natural Resource Report NPS/SFAN/NRR-2012/574. National Park Service, Fort Collins, CO. 428 pp.
  • Klein, A., J. Crawford, J. Evens, T. Keeler-Wolf, and D. Hickson. 2007. Classification of the vegetation alliances and associations of the northern Sierra Nevada foothills, California. Volumes 1 and 2. Report prepared for California Department of Fish and Game, Habitat Conservation Division. California Native Plant Society, Sacramento, CA. [https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=18232&inline=1]
  • Klein, A., and J. Evens. 2006. Vegetation alliances of western Riverside County, California. Contract Number: P0185404. Final report prepared for The California Department of Fish and Game, Habitat Conservation Division. California Native Plant Society, Sacramento, CA. 332 pp. [http://www.dfg.ca.gov/biogeodata/vegcamp/pdfs/VegMappingRpt_Western_Riverside.pdf]
  • O''Leary, J. F. 1990. Californian coastal sage scrub: General characteristics and considerations for biological conservation. Pages 24-41 in: A. A. Schoenherr, editor. Endangered plant communities of southern California. Proceedings of the 15th Annual Symposium. Special Publication No. 3. Southern California Botanists, Fullerton, CA.
  • 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.
  • Sproul, F., T. Keeler-Wolf, P. Gordon-Reedy, J. Dunn, A. Klein, and K. Harper. 2011. Vegetation classification manual for western San Diego County. AECOM, California Department of Fish and Game, San Diego Area Governments.
  • Uchytil, R. J. 1991c. Cercocarpus montanus. In: Fire Effects Information System [Online]. USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). [http://www.fs.fed.us/database/feis/]