Plant Assessment Form

Briza maxima

Common Names: big quakinggrass; rattlesnake grass; large quakinggrass,

Evaluated on: 6/30/05

List committee review date: 08/07/2005

Re-evaluation date:

Evaluator(s)

Joseph M. DiTomaso
University of California, Davis
Dept. Plant Sci., Mail Stop 4, Davis, CA 95616
530-754-8715
jmditomaso@ucdavis.edu

List commitee members

Jake Sigg
Peter Warner
Bob Case
John Knapp
Elizabeth Brusati

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

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

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? C Observational
Identify ecosystem processes impacted:

Can increase fire frequency like most other annual grasses. Generally does not form very dense stands.


Sources of information:

DiTomaso, observational


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

In some sites it can form dense, nearly pure stands, that displace other species, but this is unusual. Typically it is in a mixed community with other annual grasses and forbs. Can be locally dominant and has a negative impact on Chorizanthe howelli, a rare plant in Mendocino County.


Sources of information:

1. DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.
2. Peter Warner, California Dept. of Parks and Recreation, Mendocino, pers. obs.


Question 1.3 Impact on higher trophic levels? D Observational
Identify type of impact or alteration:

A good forage for livestock and wildlife although yields are low. No known negative impacts.


Sources of information:

DiTomaso, observational


Question 1.4 Impact on genetic integrity? D Other Published Material

No native Briza species in California.


Sources of information:

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


Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
B Observational
Describe role of disturbance:

Roadsides, fields, grassland, pastures, ditches, open woodland, coastal terraces and bluffs. Both species tolerate some shade. Also old vineyards, stabilized dunes. Typically prefers disturbance.
Needs initial disturbance for colonization, but then persists for years.


Sources of information:

DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.
2. Peter Warner, California Dept. of Parks and Recreation, Mendocino, pers. obs.


Question 2.2 Local rate of spread with no management? B Observational
Describe rate of spread:

Populations oscillate, but in general it does not expand much when in an area. Seems to be in most habitats that it can occupy. In the Bay Area, is locally spreading and is more abundant than it was years ago.


Sources of information:

DiTomaso, observational.
Jake Sigg, California Native Plant Society, San Francisco, pers. obs.


Question 2.3 Recent trend in total area infested within state? C Observational
Describe trend:

Does not appear to be expanding range in the state.


Sources of information:

DiTomaso, observational.


Question 2.4 Innate reproductive potential? C Other Published Material
Describe key reproductive characteristics:

Annual with large short lived seeds.


Sources of information:

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


Question 2.5 Potential for human-caused dispersal? B Observational
Identify dispersal mechanisms:

Perhaps with livestock and with hay, but most seed fall directly to soil below plant. Caltrans might move it during roadside mowing.


Sources of information:

DiTomaso, observational.
2. Peter Warner, California Dept. of Parks and Recreation, Mendocino, pers. obs.


Question 2.6 Potential for natural long-distance dispersal? D Observational
Identify dispersal mechanisms:

Seed primarily fall to ground below parent plant. No mechanism of long distance dispersal. Can occur close to water and this could move seed long distances on occasion but the plant does not usually grow near water souces.


Sources of information:

DiTomaso, observational.


Question 2.7 Other regions invaded? C Observational
Identify other regions:

Likely inhabits similar habitat elsewhere. Well distributed in state. Present in Montana, in grasslands and openings in forests.


Sources of information:

DiTomaso, observational.
Jake Sigg, California Native Plant Society, pers. obs.


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? A Other Published Material

Roadsides, fields, grassland, pastures, ditches, open woodland, coastal terraces and bluffs. Both species tolerate some shade. Also old vineyards, stabilized dunes.


Sources of information:

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


Question 3.2 Distribution/Peak frequency? C Observational
Describe distribution:

Most common on coast and in coastal woodlands and grasslands.


Sources of information:

DiTomaso, observational.


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 Unknown
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: 4
Total unknowns: 1
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
DunescoastalD, < 5%
desert
interior
Scrub and Chaparralcoastal bluff scrubC, 5% - 20%
coastal scrubD, < 5%
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparral
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairieC, 5% - 20%
valley and foothill grasslandD, < 5%
Great Basin grassland
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 woodlandD, < 5%
piñon and juniper woodland
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): C

Infested Jepson Regions

Click here for a map of Jepson regions

  • Cascade Range
  • Central West
  • Great Valley
  • Northwest
  • Sierra Nevada
  • Southwest
  • Modoc Plateau