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CEGL002906 Bromus diandrus Ruderal Grassland

Type Concept Sentence: Bromus diandrus is abundant in the herbaceous layer, and Brassica nigra is often present at low cover. This association is only sampled from the Santa Monica Mountains region and the Channel Islands of southern California but has been widely observed in other parts of cismontane California.

Common (Translated Scientific) Name: Ripgut Brome Ruderal Grassland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This association is only sampled from the Santa Monica Mountains region and the Channel Islands of southern California. However, it has been widely observed (but not sampled) in other parts of cismontane California and elsewhere in the western U.S. This herbaceous association occurs on flat to steep often northwest- or southwest-facing slopes at elevations between 31 and 613 m. Bromus diandrus is abundant in the herbaceous layer, and Brassica nigra is often present at low cover. Malosma laurina, Baccharis pilularis, Sambucus nigra ssp. cerulea, Ceanothus megacarpus, Salvia mellifera, and Heteromeles arbutifolia are occasionally found in the shrub layer at low cover, and Quercus agrifolia is infrequently found in the tree layer at low cover.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Although this common association of the California annual grassland/herbaceous alliance shares species with the Brassica nigra associations of the same alliance, it is overwhelmingly dominated by Bromus diandrus. The plots sampled at Santa Monica Mountains National Recreation Area without Bromus diandrus in the summary table all have Bromus sp. listed (unidentified to species due to poor phenology) and are all likely to be Bromus diandrus. It remains to be seen how environmentally distinct this association is from the other weedy associations in the same alliance (e.g., those with Brassica nigra); however, it does seem to favor slightly wetter areas and slightly deeper soils than the Brassica nigra alliance.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: Stands of this association at Santa Monica Mountains National Recreation Area form an open to continuous herbaceous layer (10-90%, mean 38.9%) at 0.01-1 m tall. The shrub layer is sparse to open (0-22%, mean 8.4%) at 0-5 m tall. Trees are infrequently emergent (0-10% cover, mean 1.3%) with hardwoods at 0-15 m tall and conifers at 0-10 m tall. Total vegetation cover is 15-90%; mean cover is 47.9%. In this association, the herbaceous layer is open to continuous and invasive exotic Bromus diandrus is abundant. Other herbs occur at relatively low cover; for example, Brassica nigra is often included, and Hirschfeldia incana and Centaurea melitensis sometimes occur in this layer. The shrub layer occasionally includes Malosma laurina, Baccharis pilularis, Sambucus nigra ssp. cerulea (= Sambucus mexicana), Ceanothus megacarpus, Salvia mellifera, and Heteromeles arbutifolia. The tree layer infrequently includes Quercus agrifolia as an emergent.

Dynamics:  Until further inventory is completed, there is no global information.
Environmental Description:  Until further inventory is completed, there is no global information.
Geographic Range: This association is only sampled from the Santa Monica Mountains region and the Channel Islands. However, it has been widely observed (but not sampled) in other parts of cismontane California.

Nations: US

States/Provinces:  CA


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 A3870 Wild Oat - Brome species Ruderal Annual Grassland Alliance A3870 2.B.1.Na.90.a
Association CEGL002906 Ripgut Brome Ruderal Grassland CEGL002906 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: = Bromus diandrus (Sawyer et al. 2009) [42.026.21]
= Bromus diandrus Herbaceous Association (Keeler-Wolf and Evens 2006)
= Bromus diandrus Semi-natural Association (Rodriguez et al. 2017)
= Bromus diandrus Stand Type (Buck-Diaz et al. 2012)
< California Annual Grassland (Sawyer and Keeler-Wolf 1995)
< Non-native Grassland (#42200) (Holland 1986b)
Concept Author(s): T. Keeler-Wolf and J. Evens (2006)

Author of Description: T. Keeler-Wolf and J. Evens

Acknowledgements: No Data Available

Version Date: 08-24-16
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