Plant Assessment Form

Foeniculum vulgare

Common Names: fennel; sweet fennel; sweet anise

Evaluated on: 6/6/05

List committee review date: 25/10/2017

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
Jenn Erskine Ogden
Section of Evolution and Ecology, UC Davis
jaerskine@ucdavis.edu

List commitee members

Joe DiTomaso
Alison Stanton
Joanna Clines
Cynthia Roye
Doug Johnson

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate
Alert Status? No Alert
Documentation? 3 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes A Observational
Impact?
Four-part score ABCD Total Score
B
1.2 ?Impact on plant community B. Moderate Other Published Material
1.3 ?Impact on higher trophic levels C. Minor Other Published Material
1.4 ?Impact on genetic integrity D. None Other Published Material
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Other Published Material
Invasiveness?
Total Points
12 Total Score B
2.2 ?Local rate of spread with no management B. Increases less rapidly 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)
A. High Other Published Material
2.5 ?Potential for human-caused dispersal B. Moderate Other Published Material
2.6 ? Potential for natural long-distance dispersal C. Rare 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)
B. Moderate 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? A Observational
Identify ecosystem processes impacted:

Sources of information:

E-mail from Rob Klinger, UC Davis, rcklinger@ucdavis.edu


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

Once firmly established, it excludes almost all other vegetation. Established plants are competitive, and soil disturbance facilitates the development of dense stands, which can exclude native vegetation in some areas (2). The increase in vertical complexity when it invades grassland communities can increase seed input of native fleshy fruited species, but excludes many grassland species. (3,4)


Sources of information:

1. Parsons W.T. 1973. Noxious Weeds of Victoria. Inkata Press, Melbourne. Pgs. 279-280
2.DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.
3. Brenton, R.K. and Klinger, R.C. 2002. Factors influencing the control of fennel (Foeniculum vulgare) using triclopyr on Santa Cruz Island, California, USA. Natural Areas Journal 22: 135-147.
4. Erskine Ogden, J.A. and M. Rejmanek. 2005. Recovery of native plant communities after the control of a dominant invasive plant species, Foeniculum vulgare: Implications for management. Biological Conservation 125: 427-439.


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

Not prefentially grazed by animals because of its strong odor although small plants/seedlings are controlled by grazers (1,3,4). Removal of fennel on Santa Cruz island increased abundance of sideblotched lizards but decreased abundance of southern alligator lizards (2, 5). Frugivorous bird diversity increases in fennel infested grasslands as the birds use the dead fennel stems as perches (6).


Sources of information:

1. Parsons W.T. 1973. Noxious Weeds of Victoria. Inkata Press, Melbourne. Pgs. 279-280
2. Gibson, J. K. 2000. The presence of fennel affects the distribution of lizards on Santa Cruz Island. Cal-EPPC Symposium Proceeding. Vol. 6 (2000-02). pg.37 (you could also use her master's thesis at San Jose State)
3. Weeds of Australia (I believe the reference for this but don't have it at my house.
4. Erskine Ogden, J.A. personal observation
5. Gibson, J., G. Yost and S. Bros. 2005. Factors Influencing the Distribution and Abundance of Lizards Following the Removal of an Invasive Non-Native Weed on Santa Cruz Island. In Rejmanek, M., R. Thorp, S. Bros, W. Fox, S. Gleissman and J. Randall. Factors influencing diversity, composition, and assembly patterns of plant and animal commuties following the removal of an invasive exotic weed on Santa Cruz Island. Final Report to The Nature Conservancy.
6. Erskine Ogden, J.A. and M. Rejmanek. 2005. Recovery of native plant communities after the control of a dominant invasive plant species, Foeniculum vulgare: Implications for management. Biological Conservation 125: 427-439.


Question 1.4 Impact on genetic integrity? D Other Published Material

none No native Foeniculum species.


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 Other Published Material
Describe role of disturbance:

Typically inhabits waste places, roadsides, and other disturbed areas. Usually found in areas that are so disturbed as to be of low ecological quality. Feral animal disturbance also promotes germination and spread (2,3). Also found in undisturbed sites.


Sources of information:

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

In last 5 years has spread north east up Hwy 80 from Fairfield, CA, area to Vacaville, Davis, and northeastward (2).


Sources of information:

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

Abundant, so probably not spreading much- following highway corridors and spreading both north and east.


Sources of information:

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

Can reproduce from both crown and seeds. Seeds germinate at almost any time of year, but plants generally do not flower until they are 18 mo. to two years old. Seeds are produced during the summer and autumn and the flowering stems die back during winter to be replaced by new growth in late winter. Some stems stay alive towards the base and produce new leaves from nodes along the stems during the winter. Seed production is usually prolific. Seed production per plant is in the tens of thousands in its first year of growth (when reproduces) and hundreds of thousands in its second year of growth (3).


Sources of information:

1. DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.
2. Parsons W.T. Noxious Weeds of Victoria. Inkata Press, Melbourne. Pgs. 279-280. 1973.
3. Erskine Ogden, J.A. 2004. Integrating ecology and conservation in an invasive species context: a case study using Foeniculum vulgare. Dissertation, University of California, Davis.


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

Can be spread by cultivation equipment or earth-moving machinery. Seeds can contaminate machinery, agricultural produce, livestock, and clothing (1).


Sources of information:

1. Parsons W.T. 1973. Noxious Weeds of Victoria. Inkata Press, Melbourne. Pgs. 279-280.


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

Seeds disperse with water and animals but this is probably rare for long distance movement.


Sources of information:

Parsons W.T. Noxious Weeds of Victoria. Inkata Press, Melbourne. Pgs. 279-280. 1973.


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

Widely distributed throughout temperate regions of the world, including New Zealand, Australia, the British Isles, and North America, usually as a weed of waste places and roadsides. Also considered a weedy species in non-native areas of Europe and the Mediterranean region. Scoring as C because already abundant in California.


Sources of information:

Parsons W.T. Noxious Weeds of Victoria. Inkata Press, Melbourne. Pgs. 279-280. 1973.


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

On Santa Cruz Island, invades grasslands, coastal sage, and chaparral. Generally not successful invading chaparral but can extend at least 10m into coastal sage from invaded grasslands (1).Fennel invades grasslands, riparian areas, and other natural communities, particularly in coastal regions of Central and Southern California. Quite common along roadsides (2). Naturalized in 1880's on mainland and by 1997 on Santa Cruz Island (3).


Sources of information:

1. Beatty S.W., Licari D.L. 1992. Invasion of Fennel (Foeniculum vulgare) Into Shrub Communities on Santa Cruz Island, California. Madrono 39(1): 54-66.
2. DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.
3. Greene, E. 1887. Studies of the botany of California and parts adjacent, VI. Notes on the botany of Santa Cruz Island. Bulletin of the California Academy of Sciences 2: 377-418.


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

Most common throughout low elevation areas of California, except Great Basin and desert regions (1). Much more common along the coast in Southern and Central California as well as the Bay Area (2). Beginning to proliferate in more central regions following the Hwy 80 and 5 corridors (3).


Sources of information:

1. DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.
2. Joe DiTomaso, Weed Science Program, UC Davis, observational.
3. Erskine Ogden, J., 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 Yes
Seeds remain viable in soil for three or more years Yes
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 Yes
Total points: 8
Total unknowns: 1
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 scrubB, 20% - 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 prairieB, 20% - 50%
valley and foothill grasslandC, 5% - 20%
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 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): B

Infested Jepson Regions

Click here for a map of Jepson regions

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