Print Report

M046 Avena fatua - Brassica nigra - Bromus diandrus Ruderal Grassland, Meadow & Scrub Macrogroup

Type Concept Sentence: This macrogroup encompasses non-native-dominated by annual grassland, forbland and scrub found in the "Mediterranean" region of California, especially in disturbed areas. Dominant introduced species include the herbs Avena barbata, Avena fatua, Brassica nigra, Bromus diandrus, Bromus hordeaceus, Bromus rubens, Centaurea spp., Erodium spp., Lolium perenne ssp. multiflorum, and Raphanus sativus. Species in non-native shrublands include Ulex europaeus, Cytisus scoparius, and species of Genista and Spartium, among others.

Common (Translated Scientific) Name: Wild Oat - Black Mustard - Ripgut Brome Ruderal Grassland, Meadow & Scrub Macrogroup

Colloquial Name: Californian Ruderal Grassland, Meadow & Scrub

Hierarchy Level:  Macrogroup

Type Concept: This macrogroup encompasses the non-native-dominated annual or perennial grasslands, forblands and scrub found in the Californian chaparral region ("Mediterranean" California). Dominant introduced graminoid species include Aegilops triuncialis, Avena barbata, Avena fatua, Brachypodium distachyon, Briza maxima, Bromus diandrus, Bromus hordeaceus, Bromus rubens, Cynosurus echinatus, Hordeum murinum, Lolium perenne ssp. multiflorum, Taeniatherum caput-medusae, Vulpia bromoides, and Vulpia myuros. Introduced forb species include Brassica nigra, Carduus pycnocephalus, Centaurea spp., Conium maculatum, Erodium botrys, Erodium cicutarium, Foeniculum vulgare, Geranium dissectum, Hypochaeris glabra, and Medicago polymorpha. Species in non-native shrublands include Acacia cyclops, Ulex europaeus, Cytisus scoparius, and species of Genista and Spartium, among others. There are many more species that can be dominant. They occur on the coastal plains, in the Central Valley, in the foothills and in disturbed rural and urban areas. California annual grassland is found at a wide variety of soils, sometimes in complex mosaics. Most are noncalcic Mollisols, medium to heavy texture, about 0.5 m deep. Native graminoid and forb species can be present with low or insignificant cover. The overwhelming dominance of the introduced species is undeniable. Non-native species make up 50-96% of the foliar cover.

Diagnostic Characteristics: Strong dominance by exotic, introduced and/or non-native annual grass and forb species, such as Avena barbata, Avena fatua, Brassica nigra, Bromus diandrus, Bromus hordeaceus, Bromus madritensis, Bromus rubens, Centaurea melitensis, Centaurea solstitialis, Erodium botrys, Erodium cicutarium, Hordeum murinum, Lolium perenne ssp. multiflorum, Raphanus sativus, Schismus spp., and Taeniatherum caput-medusae. These stands have low or insignificant cover of native grasses or forbs, even during peak phenology.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Some exotic grasses, forbs and shrubs of this macrogroup are shared with ~Western North American Ruderal Grassland & Shrubland Macrogroup (M493)$$, especially ~Southern Vancouverian Lowland Ruderal Grassland & Shrubland Group (G648)$$, including Cytisus scoparius and Ulex europaeus. It is not clear whether sufficient diagnostics provide an effective way to discriminate stands dominated by these exotics across these divisions (cool-temperate Pacific coastal versus warm-temperate/Mediterranean California).

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Herbaceous vegetation composed of annual grasses and forbs. Height variable, but generally <1m.

Floristics: Non-native graminoids include Aegilops triuncialis, Avena barbata, Avena fatua, Brachypodium distachyon, Briza maxima, Bromus diandrus, Bromus hordeaceus, Bromus madritensis, Bromus rubens, Cynosurus echinatus, Hordeum murinum, Lolium perenne ssp. multiflorum (= Lolium multiflorum), Schismus arabicus, Schismus barbatus, Taeniatherum caput-medusae (= Elymus caput-medusae), Vulpia bromoides (= Festuca bromoides), and Vulpia myuros (= Festuca myuros). Non-native forb species include Brassica nigra, Carduus pycnocephalus, Centaurea melitensis, Centaurea solstitialis, Centaurea virgata, Glebionis coronarium, Conium maculatum, Erodium botrys, Erodium cicutarium, Foeniculum vulgare, Geranium dissectum, Hirschfeldia incana, Hypochaeris glabra, Leontodon taraxacoides, Medicago polymorpha, Raphanus sativus, and Silybum marianum. Species in non-native shrublands include Ulex europaeus, Cytisus scoparius, and species of Genista and Spartium, among others.

Dynamics:  Stands are a result of the introduction of annual herbaceous and scrub species that successfully compete with native grassland species, especially after significant and repeated disturbance. In addition, these stands are adapted to frequent fires and summer droughts (Sawyer et al. 2009).
Environmental Description:  These grasslands and scrub occur across many environmental settings, though mostly on fine-textured soils, below approximately 1200 m in elevation, and tend not to occur on harsh serpentinite soils. Ruderal scrubs tend to develop on degraded soils of excavations, scrapes, and landslides. Ruderal grasslands tend to develop on fallow agriculture and other heavily disturbed sites.
Geographic Range: This macrogroup occurs throughout Mediterranean California below about 1200 m in elevation.

Nations: MX,US

States/Provinces:  CA, OR?


Confidence Level: High

Confidence Level Comments: No Data Available
Grank: GNA

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.90 Wild Oat - Black Mustard - Ripgut Brome Ruderal Grassland, Meadow & Scrub Macrogroup M046 2.B.1.Na.90
Group 2.B.1.Na.90.a Wild Oat - Ripgut Brome Ruderal Grassland, Meadow & Scrub Group G497 2.B.1.Na.90.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: < Coastal Prairie (214) (Shiflet 1994) [The annual introduced grassland corresponds with this macrogroup.]
< Valley Grassland (215) (Shiflet 1994) [The annual grassland part corresponds with this macrogroup.]
Concept Author(s): M.G. Barbour, T. Keeler-Wolf and A.A. Schoenherr (2007a)

Author of Description: G. Kittel, M. Reid, D. Faber-Langendoen

Acknowledgements: No Data Available

Version Date: 01-13-16
  • Barbour, M. G., T. Keeler-Wolf, and A. A. Schoenherr, editors. 2007a. Terrestrial vegetation of California, third edition. University of California Press, Berkeley.
  • Bartolome, J. W. W. J. Barry, T. Griggs, and P. Hopkinson. 2007. Valley grassland. Pages 367-393 in: M. G. Barbour, T. Keeler-Wolf and A. A. Schoenherr. Terrestrial vegetation of California, 3rd ed. University of California Press, Berkeley.
  • 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, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
  • 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.
  • 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]
  • 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.
  • Shiflet, T. N., editor. 1994. Rangeland cover types of the United States. Society for Range Management. Denver, CO. 152 pp.