Print Report

G497 Avena fatua - Bromus diandrus Ruderal Grassland, Meadow & Scrub Group

Type Concept Sentence: This warm-temperate Californian ruderal grassland, forbland and scrub group is most commonly dominated by non-native annual or perennial herbaceous species which compose >75% of the foliar cover and include many graminoids such as Avena barbata, Avena fatua, Bromus diandrus, Bromus hordeaceus, Bromus madritensis, Cortaderia jubata, Cortaderia selloana, Lolium perenne ssp. multiflorum, Hordeum murinum, Taeniatherum caput-medusae, Vulpia bromoides, Vulpia myuros, and forbs, including Carduus pycnocephalus, Centaurea spp., Erodium botrys, Erodium cicutarium, Medicago polymorpha, Geranium dissectum, Hypochaeris glabra, and Raphanus sativus.

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

Colloquial Name: Californian Ruderal Grassland, Meadow & Scrub

Hierarchy Level:  Group

Type Concept: This group encompasses the non-native-dominated annual or perennial grasslands and forblands found in warm-temperate or Mediterranean California. They occur on the coastal plains, in the Central Valley, in the foothills and in disturbed rural and urban areas. 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. Dominant introduced graminoid species include Aegilops triuncialis, Avena fatua, Avena barbata, Bromus diandrus, Bromus hordeaceus, Bromus madritensis, Cortaderia jubata, Cortaderia selloana, Lolium perenne ssp. multiflorum, Hordeum murinum, Pennisetum ciliare, Pennisetum setaceum, Taeniatherum caput-medusae, Vulpia bromoides, and Vulpia myuros. Introduced forb species include Brassica nigra, Carduus pycnocephalus, Centaurea spp., Erodium botrys, Erodium cicutarium, Medicago polymorpha, Geranium dissectum, Hypochaeris glabra, Medicago polymorpha, and Raphanus sativus. Species in non-native shrublands include Ulex europaeus, Cytisus scoparius , and species of Genista and Spartium, among others. There are many more species that can be dominant. California annual grassland is found on a wide variety of soils, sometimes in complex mosaics. Most are noncalcic Mollisols, medium to heavy texture, about 0.5 m deep.

Diagnostic Characteristics: Dominance by exotic, introduced and/or non-native annual or perennial grass and forb species, such as Aegilops triuncialis, Avena barbata, Avena fatua, Brachypodium distachyon, Briza maxima, Bromus diandrus, Bromus hordeaceus, Bromus madritensis, Bromus rubens, Cortaderia jubata, Cortaderia selloana, Cynosurus echinatus, Hordeum murinum, Lolium perenne ssp. multiflorum, Hordeum murinum, Pennisetum ciliare, Pennisetum setaceum, Taeniatherum caput-medusae, Vulpia bromoides, and Vulpia myuros. Introduced forb species include Brassica nigra, Carduus pycnocephalus, Centaurea solstitialis, Centaurea melitensis, Centaurea virgata, Conium maculatum, Foeniculum vulgare, Erodium botrys, Erodium cicutarium, Medicago polymorpha, Geranium dissectum, Hypochaeris glabra, Medicago polymorpha, and Raphanus sativus. Species in non-native shrublands include Ulex europaeus, Cytisus scoparius, and species of Genista and Spartium, among others. Native herbaceous species may be present, but these with less than 10% relative cover in the herbaceous layer.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Non-native scrub types were added to this group. They need better characterization. Preliminary notes include the following observations: Some exotic grasses, forbs and shrubs of this macrogroup are shared with ~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 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 perennial or annual grasses and forbs. Height variable, but generally <0.5 m, although some can be much taller (e.g., Cortaderia spp. stands).

Floristics: Graminoids include Aegilops triuncialis, Avena barbata, Avena fatua, Brachypodium distachyon, Briza maxima, Bromus diandrus, Bromus hordeaceus, Bromus madritensis, Bromus rubens, Cortaderia jubata, Cortaderia selloana, Cynosurus echinatus, Hordeum murinum, Lolium perenne ssp. multiflorum (= Lolium multiflorum), Pennisetum ciliare, Pennisetum setaceum, Schismus arabicus, Schismus barbatus, Taeniatherum caput-medusae, Vulpia bromoides, and Vulpia myuros. Forb species include Brassica nigra, Carduus pycnocephalus, Centaurea melitensis, Centaurea solstitialis, Centaurea virgata, Conium maculatum, Erodium botrys, Erodium cicutarium, Foeniculum vulgare, Geranium dissectum, Hypochaeris glabra, Medicago polymorpha, and Raphanus sativus.

Species in non-native shrublands include Ulex europaeus, Cytisus scoparius, and species of Genista and Spartium, among others. Native herbaceous species may be present, but these with less than 10% relative cover in the herbaceous layer. The most ubiquitous ruderal shrub species in central California is Genista monspessulana. It tends to colonize bare soils exposed on construction sites in the California Coast Ranges and northern Sierra Nevada foothills. It quickly builds up a seed bank and, for invasives control, removal of shrubs must be followed up with repeated removal of seedlings for years. Hybrids of several species of introduced Genista and Cytisus have colonized slopes in central and southern coastal California.

Floristic information is summarized from the following sources: Evens and San (2004, 2006), Klein and Evens (2005), Keeler-Wolf and Evens (2006), and Sawyer et al. (2009).

Dynamics:  Stands are a result of historic or recent heavy continuous grazing or other disturbance. Classification to this ruderal group does not preclude the possibility of successful restoration back to the native California grassland group. Stands dominated by these annual and perennial species are adapted to frequent fires and summer droughts. Stands dominated by introduced cool-season, annual grasses have germinating seeds that survive the sporadic wetting and drying cycles that occur though the growing season. Most seeds germinate after the first significant rain in the fall. Plants set seed and die by the end of the growing season in the spring (Sawyer et al. 2009).
Environmental Description:  No Data Available
Geographic Range: This group occurs in the warm-temperate ("Mediterranean") California coastal plain and Central Valley, also in the southeastern portions of the state in transitions to California desert regions.

Nations: MX,US

States/Provinces:  AZ, CA, MXBCN, OR?, WA


Confidence Level: Moderate

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
Alliance A1203 Purple Pampas Grass - Uruguayan Pampas Grass Ruderal Grassland Alliance A1203 2.B.1.Na.90.a
Alliance A3870 Wild Oat - Brome species Ruderal Annual Grassland Alliance A3870 2.B.1.Na.90.a
Alliance A3871 Perennial Ryegrass Ruderal Grassland Alliance A3871 2.B.1.Na.90.a
Alliance A3872 Squarrose Knapweed - Poison-hemlock - Sweet Fennel Ruderal Meadow Alliance A3872 2.B.1.Na.90.a
Alliance A4214 Black Mustard - Radish species Ruderal Annual Forb Meadow Alliance A4214 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: No Data Available
Concept Author(s): G. Kittel, in Faber-Langendoen et al. (2011)

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

Acknowledgements: No Data Available

Version Date: 01-13-16
  • 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.
  • Buck-Diaz, J., J. Ratchford, and J. M. Evens. 2013. California rangeland monitoring and mapping: Focusing upon Great Valley and Carrizo Plain grassland habitats, California. Unpublished report submitted to the Natural Resources Conservation Service. California Native Society, Sacramento, CA. [http://cnps.org/cnps/vegetation/pdf/grassland_nrcs_report-2013c.pdf]
  • Buck-Diaz, J., S. Batiuk, and J. M. Evens. 2012. Vegetation alliances and associations of the Great Valley ecoregion, California. California Native Society, Sacramento, CA. [http://cnps.org/cnps/vegetation/pdf/great_valley_eco-vegclass2012.pdf]
  • Buck-Diaz, J., and J. Evens. 2011b. Carrizo Plain National Monument vegetation classification and mapping project. Report to USDI, Bureau of Land Management, California Department of Fish and Game, and The Nature Conservancy. California Native Plant Society, Sacramento, CA.
  • 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.
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  • 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]
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  • 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.