Plant Assessment Form

Brassica nigra

Synonyms: Sinapis nigra (L.)

Common Names: black mustard

Evaluated on: 3/9/04

List committee review date: 19/03/2004

Re-evaluation date:

Evaluator(s)

Matt Brooks/Research Botanist
U.S. Geological Survey
160 N.Stephanie St., Henderson, NV 89074
702-564-4615
matt_brooks@usgs.gov

List commitee members

Cynthia Roye
Carla Bossard
Doug Johnson
Joe DiTomaso
Jake Sigg
Alison Stanton
Matt Brooks
Peter Warner.

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate
Alert Status? No Alert
Documentation? 2 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes C Observational
Impact?
Four-part score CBUD Total Score
B
1.2 ?Impact on plant community B. Moderate Observational
1.3 ?Impact on higher trophic levels U. Unknown
1.4 ?Impact on genetic integrity D. None Other Published Material
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Observational
Invasiveness?
Total Points
11 Total Score B
2.2 ?Local rate of spread with no management C. Stable Observational
2.3 ?Recent trend in total area infested within state C. Stable Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
A. High Observational
2.5 ?Potential for human-caused dispersal B. Moderate Observational
2.6 ? Potential for natural long-distance dispersal C. Rare Observational
2.7 ?Other regions invaded C. Already invaded
3.1 ?Ecological amplitude/Range
(see Worksheet C)
A. Widespread Other Published Material
Distribution?
Total Score A
3.2 ?Distribution/Peak frequency
(see Worksheet C)
A. High 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:

C. Possibly fire regimes May increase fuel loads, but only where alien annual grasses have already altered the fire regime, so additional effect of this species may be only to slightly increase fire intensity.


Sources of information:

Matt Brooks personal observation


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

B. May reduce biomass and fecundity of co-existing species. Can produce large amounts of biomass, and matures early in the phenologic year, possibly usurping soil water before other native annual plants reach peak development


Sources of information:

Matt Brooks personal observation


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

U, unknown


Sources of information:

Question 1.4 Impact on genetic integrity? D Other Published Material

D. no known hybridiation There are no native Brassica species in California, although hybridization with the alien Brassica napus has been observed.


Sources of information:

Hickman, 1993. The Jepson Manual, Higher Plant of Calfifornia. U.C. Press. and Joe DiTomaso personal observation


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

B. Disturbance promotes dominance and spread. This is an early successional species, which may decline in dominance as native species re-establish, but likely varies among vegetation types. It may persist indefiniately in riparian areas with repeated natural disturbance.


Sources of information:

Matt Brooks personal observation


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

C. Slow unless there is disturbance. Occurs in habitat openings caused by nautural distubances, roads, urban developments, agricultural fields, etc.


Sources of information:

Matt Brooks personal observation


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

C. constant possibly declining where H. incana and B. tournefortii have more recently displaced B. nigra as dominant alien in sage scrub.


Sources of information:

Matt Brooks personal observation


Question 2.4 Innate reproductive potential? A Observational
Describe key reproductive characteristics:

A. high reported to establish from seedbank in chaparall after 40 year fire-free interval


Sources of information:

Jon Keeley personal communication, DiTomaso, J.M. and E.A. Healy. Weeds of California and other Western States. University of California, Division of Agriculture and Natural Resources, Oakland, CA (in press, expected publication in 2005).


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

B. moderate Mustard seeds are sticky when wet facilitating dispersal on vehicles and grow in hay fields where they may be dispersed along with the hay when it is sold. Seen on gravel bars, mudflats, roadsides, pipeline ROWs.


Sources of information:

. Matt Brooks personal observation


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

C. Low Likely dispersed by saltation or rodents.


Sources of information:

Matt Brooks personal observation


Question 2.7 Other regions invaded? C
Identify other regions:

C. low occurs in similar habitats outside California.


Sources of information:

Personal observation: Matt Brooks; Peter Warner; Joe DiTomaso.


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

A. Widespread has invaded shrublands, grasslands, and riparian areas


Sources of information:

Hickman, 1993. The Jepson Manual, Higher Plant of Calfifornia. U.C. Press. and Matt Brooks personal observation, DiTomaso, J.M. and E.A. Healy. Weeds of California and other Western States. University of California, Division of Agriculture and Natural Resources, Oakland, CA (in press, expected publication in 2005).


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

A. very frequent common in sage scrub


Sources of information:

Matt Brooks personal observation


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 Yes
Viable seed produced with both self-pollination and cross-pollination No
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: 6
Total unknowns: 0
Total score: A?

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 scrubB, 20% - 50%
coastal scrubA, > 50%
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparralD, < 5%
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairieC, 5% - 20%
valley and foothill grassland
Great Basin grassland
vernal poolD, < 5%
meadow and seep
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forestD, < 5%
riparian woodlandD, < 5%
riparian scrub (incl.desert washes)D, < 5%
Woodlandcismontane woodland
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): A

Infested Jepson Regions

Click here for a map of Jepson regions

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