Print Report

A3864 Ceanothus crassifolius - Ceanothus megacarpus Chaparral Alliance

Type Concept Sentence: This alliance consists of stands of chaparral dominated by Ceanothus megacarpus or Ceanothus crassifolius. It is seral, fire-dependent chaparral, usually with several other shrub species in the canopy. It occurs in California''s lower cismontane regions between 100 and 1350 m elevation, on shallow, rocky soils, on xeric sites, fairly near the coast but above the coastal scrub zone.

Common (Translated Scientific) Name: Hoaryleaf Ceanothus - Bigpod Ceanothus Chaparral Alliance

Colloquial Name: Hoaryleaf Ceanothus - Bigpod Ceanothus Chaparral

Hierarchy Level:  Alliance

Type Concept: This alliance consists of stands of chaparral dominated by Ceanothus megacarpus or Ceanothus crassifolius. These share the shrub canopy with Adenostoma fasciculatum, Adenostoma sparsifolium, Arctostaphylos glauca, Ceanothus leucodermis, Ceanothus spinosus, Cercocarpus montanus, Diplacus aurantiacus, Eriogonum cinereum, Eriogonum fasciculatum, Heteromeles arbutifolia, Malosma laurina, Quercus berberidifolia, Quercus dumosa, Rhamnus ilicifolia, Rhus ovata, Salvia mellifera, and/or Hesperoyucca whipplei. Emergent Juglans californica, Quercus agrifolia, and Umbellularia californica trees may be present. Tree layer is sparse and usually absent. Shrubs are <4 m in height, and the canopy is continuous to intermittent. The herbaceous layer is sparse or open, or occasionally grassy. Stands usually occur on xeric sites, fairly near the coast but above the coastal scrub zone, in central, southern, and cismontane California between 100-1350 m in elevation. At the upper end of the elevational range, stands are restricted to south-facing slopes. Soils vary in depth but are usually coarse-textured, shallow, rocky, and poorly differentiated.

Diagnostic Characteristics: Ceanothus megacarpus or Ceanothus crassifolius has 60% cover

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance combines two Sawyer et al. (2009) Ceanothus alliances based on similar habitats, fire regime, geography, and floristics. Lumping these two southern California xeric chaparral species into one alliance makes sense, even though traditionally, they have been treated as separate alliances. In Orange County and Los Angeles County, they do overlap ecologically and tend to occur adjacent to one another, so there are clear similarities (T. Keeler-Wolf pers. comm. 2013).

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This sclerophyllous, temperate, broad-leaved evergreen shrubland forms an intermittent to continuous canopy less than 4 m in height. Emergent trees (10-15 m tall) may be present. The herbaceous layer is sparse.

Floristics: Stands are dominated by Ceanothus megacarpus or Ceanothus crassifolius. These share the shrub canopy with Adenostoma fasciculatum, Adenostoma sparsifolium, Arctostaphylos glauca, Ceanothus leucodermis, Ceanothus spinosus, Cercocarpus montanus, Diplacus aurantiacus, Eriogonum cinereum, Eriogonum fasciculatum, Heteromeles arbutifolia, Malosma laurina, Quercus berberidifolia, Quercus dumosa, Rhamnus ilicifolia, Rhus ovata, Salvia mellifera, and/or Hesperoyucca whipplei. Emergent Juglans californica, Quercus agrifolia, and Umbellularia californica trees may be present.

Dynamics:  This alliance becomes established after fire and then succeeds into other types of chaparral. Therefore it is considered a fire-dependent seral vegetation type. Stands become thin over time as Ceanothus crassifolius and Ceanothus megacarpus begin to die back after about 40 years (and no subsequent fire).
Environmental Description:  Stands of this xeric chaparral vegetation type occur on slopes from 100 to 1350 m in elevation. At the upper end of the elevational range, stands are restricted to south-facing slopes. Soils are shallow, rocky and poorly differentiated. Stands usually occur on xeric sites, fairly near the coast but above the coastal scrub zone. Precipitation patterns are very Mediterranean, with the bulk of the precipitation falling between November and May. Yearly rainfall totals vary between 25 and 80 cm, with much year-to-year variation.
Geographic Range: This alliance is found in lower cismontane California (central and southern).

Nations: MX?,US

States/Provinces:  CA, MXBCN?


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: GNR

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.a Chamise - Buckbrush - Sticky Whiteleaf Manzanita Xeric Chaparral Group G257 2.B.1.Na.1.a
Alliance A3864 Hoaryleaf Ceanothus - Bigpod Ceanothus Chaparral Alliance A3864 2.B.1.Na.1.a
Association CEGL002926 Chamise - Bigpod Ceanothus Shrubland CEGL002926 2.B.1.Na.1.a
Association CEGL003029 Bigpod Ceanothus - Birchleaf Mountain-mahogany Shrubland CEGL003029 2.B.1.Na.1.a
Association CEGL003030 Bigpod Ceanothus - Hollyleaf Redberry Shrubland CEGL003030 2.B.1.Na.1.a
Association CEGL003500 Chamise - Redshank - Hoaryleaf Ceanothus Shrubland CEGL003500 2.B.1.Na.1.a
Association CEGL003517 Chamise - Hoaryleaf Ceanothus - Laurel Sumac Shrubland CEGL003517 2.B.1.Na.1.a
Association CEGL003552 Hoaryleaf Ceanothus Shrubland CEGL003552 2.B.1.Na.1.a
Association CEGL003557 Hoaryleaf Ceanothus - Laurel Sumac Shrubland CEGL003557 2.B.1.Na.1.a
Association CEGL003562 Bigpod Ceanothus Shrubland CEGL003562 2.B.1.Na.1.a
Association CEGL003565 Bigpod Ceanothus - Chamise Shrubland CEGL003565 2.B.1.Na.1.a
Association CEGL003566 Bigpod Ceanothus - Redshank Shrubland CEGL003566 2.B.1.Na.1.a
Association CEGL003567 Bigpod Ceanothus - Laurel Sumac Shrubland CEGL003567 2.B.1.Na.1.a
Association CEGL003574 Bigpod Ceanothus - Black Sage Shrubland CEGL003574 2.B.1.Na.1.a
Concept Lineage: includes A.764 and A.770

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: > Ceanothus crassifolius (Hoary leaf ceanothus chaparral) Alliance (Sawyer et al. 2009) [37.208.00]
> Ceanothus crassifolius Chaparral (#37830) (Holland 1986b)
> Ceanothus megacarpus (Big pod ceanothus chaparral) Alliance (Sawyer et al. 2009) [37.201.00]
> Ceanothus megacarpus Chaparral (#37840) (Holland 1986b)
Concept Author(s): M.S. Reid after Sawyer et al. (2009)

Author of Description: M.S. Reid

Acknowledgements: No Data Available

Version Date: 12-18-14
  • 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.
  • 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.
  • Keeler-Wolf, T. Personal communication. Senior Vegetation Ecologist, Wildlife and Habitat Data Analysis Branch, California Department of Fish and Game, Sacramento, 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.