Plant Assessment Form

Bromus hordeaceus

Synonyms: Bromus confertus Boreau. (B. racemosus and B. scoparious mistakenly used in some older references)

Common Names: soft brome; soft chess; lopgrass

Evaluated on: 2/24/05

List committee review date: 08/07/2005

Re-evaluation date:

Evaluator(s)

Elizabeth Brusati, project manager
California Invasive Plant Council
1442A Walnut St. #462, Berkeley, CA 94709
510-843-3902
edbrusati@cal-ipc.org
Joseph DiTomaso
University of California-Davis
Dept. Plant Sci., Mail Stop 4, Davis, CA 95616
530-754-8715
jmditomaso@ucdavis.edu

List commitee members

Carla Bossard
John Randall
Carri Pirosko
Dan Gluesenkamp
Gina Skurka
Brianna Richardson

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? Limited
Alert Status? No Alert
Documentation? 3 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes B Observational
Impact?
Four-part score BACU Total Score
B
1.2 ?Impact on plant community A. Severe Other Published Material
1.3 ?Impact on higher trophic levels C. Minor Other Published Material
1.4 ?Impact on genetic integrity U. Unknown
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Other Published Material
Invasiveness?
Total Points
9 Total Score C
2.2 ?Local rate of spread with no management C. Stable Other Published Material
2.3 ?Recent trend in total area infested within state C. Stable Other Published Material
2.4 ?Innate reproductive potential
(see Worksheet A)
B. Moderate Reviewed Scientific Publication
2.5 ?Potential for human-caused dispersal B. Moderate Other Published Material
2.6 ? Potential for natural long-distance dispersal D. None Other Published Material
2.7 ?Other regions invaded C. Already invaded Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
A. Widespread Reviewed Scientific Publication
Distribution?
Total Score A
3.2 ?Distribution/Peak frequency
(see Worksheet C)
A. High Other Published Material

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".

Section 1: Impact
Question 1.1 Impact on abiotic ecosystem processes? B Observational
Identify ecosystem processes impacted:

<p>A dominant part of the grassland system in California. Undoubtedly has contributed to the increased frequency of fires.</p>


Sources of information:

<p>DiTomaso, observational Dan Gluesenkamp, Audubon Canyon Ranch, pers. obs. John Randall, The Nature Conservancy, pers. obs.</p>


Question 1.2 Impact on plant community composition,
structure, and interactions?
A Other Published Material
Identify type of impact or alteration:

<p>Displaces perennial grasses by outcompeting them for moisture early in the season.</p>


Sources of information:

<p>DiTomaso, J., and E. Healy. in prep. Weeds of California and Other Western States.</p>


Question 1.3 Impact on higher trophic levels? C Other Published Material
Identify type of impact or alteration:

<p>Good forage species</p>


Sources of information:

<p>DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.</p>


Question 1.4 Impact on genetic integrity? U

<p>There are numerous native and introduced species of Bromus. No information on hybridization but probably unlikely.</p>


Sources of information:

<p>Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA enter text here</p>


Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
C Other Published Material
Describe role of disturbance:

<p>Inhabits open disturbed sites.</p>


Sources of information:

<p>DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.</p>


Question 2.2 Local rate of spread with no management? C Other Published Material
Describe rate of spread:

<p>Already present throughout California so probably not spreading much.</p>


Sources of information:

<p>DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.</p>


Question 2.3 Recent trend in total area infested within state? C Other Published Material
Describe trend:

<p>Already present throughout California so probably not spreading much.</p>


Sources of information:

<p>DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.</p>


Question 2.4 Innate reproductive potential? B Reviewed Scientific Publication
Describe key reproductive characteristics:

<p>Cool season annual. Flowers April-July. Often self-pollinated. Reproduces by seed. Most seeds germinate after first rains in fall, but can germinate in early to mid-spring (1). Seeds can germinate on or below the soil surface (2).</p>


Sources of information:

<p>1. DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488. 2. Flood, R. G. Germination of soft brome (Bromus hordeaceus). Plant Protection Quarterly 1(4): 144-147.</p>


Question 2.5 Potential for human-caused dispersal? B Other Published Material
Identify dispersal mechanisms:

<p>Seeds dispersed by vehicle tires, human activities, and as seed contaminants.</p>


Sources of information:

<p>DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.</p>


Question 2.6 Potential for natural long-distance dispersal? D Other Published Material
Identify dispersal mechanisms:

<p>Can be dispersed by mud, water, and animals, but long distance movement is probably very uncommon.</p>


Sources of information:

<p>DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.</p>


Question 2.7 Other regions invaded? C Other Published Material
Identify other regions:

<p>Nearly worldwide. One or more subspecies occur in most contiguous states, except possibly Wyoming and a few southern, central, and eastern states (1).</p>


Sources of information:

<p>DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.</p>


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? A Reviewed Scientific Publication

Throughout California, mostly to 1000m, occasionally to 2100m. Common in northern and central regions of the state, uncommon in desert. Grasslands, sagebrush communities, rangeland, fields, open disturbed areas, roadsides. Thrives on fertile soil but can also colonize low-fertility soils such as serpentine (1). Inhabits grasslands near oaks but is outcompeted by B. diandrus under oak canopies (2). The only non-native species that invades the serpentine soil significantly (3).


Sources of information:

1. DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488. 2. Rice, K.J., and E. S. Nagy. 2000. Oak canopy effects on the distribution patterns of two annual grasses: the role of competition and soil nutrients. American Journal of Botany. 87:1699-1706 3. Freitas, H. and H. Mooney. 1996. Effects of water stress and soil texture on the performance of two Bromus hordeaceus ecotypes from sandstone and serpentine soils. Acta Oecologica 17(4): 307-317.


Question 3.2 Distribution/Peak frequency? A Other Published Material
Describe distribution:

One of the most common annual grasses in the state. Found in nearly all grassland sites.


Sources of information:

DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.


Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter Yes
Populations of this species produce seeds every year. Yes
Seed production sustained over 3 or more months within a population annually No
Seeds remain viable in soil for three or more years No
Viable seed produced with both self-pollination and cross-pollination Yes
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes No
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned No
Total points: 5
Total unknowns: 0
Total score: B?

Related traits:

Worksheet B - Arizona Ecological Types is not included here

Worksheet C - California Ecological Types

(sensu Holland 1986)
Major Ecological Types Minor Ecological Types Code?
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
estuaries
Dunescoastal
desert
interior
Scrub and Chaparralcoastal bluff scrubD, < 5%
coastal scrubC, 5% - 20%
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrubC, 5% - 20%
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparralC, 5% - 20%
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairieA, > 50%
valley and foothill grasslandA, > 50%
Great Basin grasslandB, 20% - 50%
vernal pool
meadow and seep
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forest
riparian woodland
riparian scrub (incl.desert washes)
Woodlandcismontane woodlandA, > 50%
piñon and juniper woodlandC, 5% - 20%
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forest
closed cone coniferous forest
lower montane coniferous forest
upper montane coniferous forest
subalpine coniferous forest
Alpine Habitatsalpine boulder and rock field
alpine dwarf scrub
Amplitude (breadth): A
Distribution (highest score): A

Infested Jepson Regions

Click here for a map of Jepson regions

  • ALL
  • CA Floristic Province
  • Cascade Range
  • Central West
  • Desert Province
  • Mojave Desert
  • Sonoran Desert
  • Great Basin Province
  • Great Valley
  • Modoc Plateau
  • Northwest
  • Sierra Nevada
  • Sierra Nevada East
  • Southwest