Print Report

A3917 Ceanothus cordulatus - Ceanothus integerrimus Shrubland Alliance

Type Concept Sentence: This alliance consists of shrublands dominated by either Ceanothus cordulatus or Ceanothus integerrimus, with other montane chaparral shrubs. This alliance occurs in cismontane California and mountains of southern Oregon. Stands occur on well-drained soils and are best developed on dry, exposed sites such as along ridges and upper slopes, between 300 and 2100 m elevation.

Common (Translated Scientific) Name: Mountain Whitethorn - Deerbrush Shrubland Alliance

Colloquial Name: Californian Montane Whitethorn - Deerbrush Chaparral

Hierarchy Level:  Alliance

Type Concept: This chaparral shrubland alliance is dominated by either Ceanothus cordulatus or Ceanothus integerrimus, with other montane chaparral shrubs, including Arctostaphylos manzanita, Arctostaphylos patula, Arctostaphylos viscida, Ceanothus cuneatus, Ceanothus sanguineus (in Oregon), Ceanothus velutinus, Chrysolepis sempervirens, Holodiscus discolor, Notholithocarpus densiflorus, Prunus emarginata, Quercus berberidifolia, Quercus chrysolepis, Quercus vacciniifolia, and Symphoricarpos mollis. Emergent trees may be present and can include Pseudotsuga menziesii, Arbutus menziesii, and Quercus wislizeni. The herbaceous layer is sparse and typically includes Elymus glaucus. These are generally short-lived shrublands (on the order of decades), succeeding to conifer woodlands or forest. Stands establish from seed banks post-fire or after other disturbance such as logging; too frequent fires can deplete the seed bank. This chaparral shrubland of cismontane California and mountains of southern Oregon is found between 300 and 2100 m elevation. This is a region with strong seasonal precipitation patterns: long, dry summers and cool, moist winters. Precipitation varies from 30 cm per year in the southern portions of the range to 200 cm per year in the northern. Stands occur on well-drained soils and are best developed on dry, exposed sites such as along ridges and upper slopes.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: While one of these dominants is evergreen and the other is semi-deciduous or deciduous, they share many floristic characteristics, dynamics, and environmental setting, so they are placed in a single alliance.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This sclerophyllous, temperate, broad-leaved evergreen shrubland forms a continuous to intermittent shrub canopy with a sparse herbaceous layer. Emergent conifers (10-15 m tall) may be present.

Floristics: This chaparral shrubland alliance is dominated by either Ceanothus cordulatus or Ceanothus integerrimus, with other montane chaparral shrubs, including Arctostaphylos manzanita, Arctostaphylos patula, Arctostaphylos viscida, Ceanothus cuneatus, Ceanothus sanguineus (in Oregon), Ceanothus velutinus, Chrysolepis sempervirens, Holodiscus discolor, Notholithocarpus densiflorus (= Lithocarpus densiflorus), Prunus emarginata, Quercus berberidifolia, Quercus chrysolepis, Quercus vacciniifolia, and Symphoricarpos mollis. Emergent trees may be present and can include Pseudotsuga menziesii, Arbutus menziesii, and Quercus wislizeni. The herbaceous layer is sparse and typically includes Elymus glaucus.

Dynamics:  This alliance is not normally self-perpetuating. It is transitional to other forest vegetation types, and requires disturbances such as logging and fire to provide openings within suitable habitat.
Environmental Description:  This alliance occurs along ridges and upper slopes between 900 and 2900 m in elevation. Stands occur on well-drained soils and are best developed on dry, exposed sites. This alliance grows in a climate with long, dry summers and wet winters. Average yearly precipitation totals vary from roughly 62 cm in the northern end of the range to 30 cm in the southern extremes.
Geographic Range: This alliance occurs from Oregon to southern California. Stands are found in the Klamath Mountains, Coast and Cascade ranges, Sierra Nevada, and Transverse and Peninsular ranges.

Nations: US

States/Provinces:  CA, OR


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.2 Temperate Grassland & Shrubland Formation F012 2.B.2
Division 2.B.2.Ng Western North American Interior Chaparral Division D061 2.B.2.Ng
Macrogroup 2.B.2.Ng.1 Greenleaf Manzanita - Snowbrush Ceanothus - Huckleberry Oak Montane Chaparral Macrogroup M094 2.B.2.Ng.1
Group 2.B.2.Ng.1.a Greenleaf Manzanita - Pinemat Manzanita - Snowbrush Ceanothus Montane Sclerophyll Scrub Group G282 2.B.2.Ng.1.a
Alliance A3917 Mountain Whitethorn - Deerbrush Shrubland Alliance A3917 2.B.2.Ng.1.a
Association CEGL003023 Mountain Whitethorn Shrubland CEGL003023 2.B.2.Ng.1.a
Association CEGL003027 Deerbrush Shrubland CEGL003027 2.B.2.Ng.1.a
Association CEGL005818 Deerbrush - Sticky Whiteleaf Manzanita - (Indian Manzanita) Shrubland CEGL005818 2.B.2.Ng.1.a
Association CEGL005821 Mountain Whitethorn / Sparse Understory Sierran Shrubland CEGL005821 2.B.2.Ng.1.a
Concept Lineage: includes A.763 and A.895

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: > Ceanothus cordulatus (Mountain white thorn chaparral) Alliance (Sawyer et al. 2009) [37.209.00]
> Ceanothus integerrimus (Deer brush chaparral) Alliance (Sawyer et al. 2009) [37.206.00]
> Ceanothus integerrimus Shrubland Alliance (Keeler-Wolf et al. 2012)
= Deer Brush Chaparral (#37531) (Holland 1986b)
= Whitethorn Chaparral (#37532) (Holland 1986b)
Concept Author(s): M.S. Reid, in Faber-Langendoen et al. (2013)

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., P. E. Moore, E. T. Reyes, J. M. Menke, D. N. Johnson, and D. L. Karavidas. 2012. Yosemite National Park vegetation classification and mapping project report. Natural Resource Technical Report NPS/YOSE/NRTR--2012/598. National Park Service, Fort Collins, 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.