Plant Assessment Form

Ulex europaeus

Synonyms: Ulex europaea

Common Names: gorse; common gorse; furze; prickly broom

Evaluated on: 8/11/03

List committee review date: 23/11/2017

Re-evaluation date:

Evaluator(s)

Cynthia L. Roye, Associate State Park Resource Ecologist
California State Parks, Natural Resources Division
P.O. Box 942896, Sacramento, CA 94296-0001
(916) 653-9083
croye@parks.ca.gov

List commitee members

Matt Brooks
Joe DiTomaso
Peter Warner
Doug Johnson

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? High
Alert Status? No Alert
Documentation? 3 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes A Other Published Material
Impact?
Four-part score AABD Total Score
A
1.2 ?Impact on plant community A. Severe Other Published Material
1.3 ?Impact on higher trophic levels B. Moderate 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
11 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 Reviewed Scientific Publication
2.4 ?Innate reproductive potential
(see Worksheet A)
A. High Other Published Material
2.5 ?Potential for human-caused dispersal C. Low 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 Observational
Distribution?
Total Score B
3.2 ?Distribution/Peak frequency
(see Worksheet C)
D. Very 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? A Other Published Material
Identify ecosystem processes impacted:

Soil chemistry, fire frequency, fire intensity Associated with nitrogen-fixing bacteria so adds nitrogen to soils; leaf litter acidifies and lowers cation exchange capacity of moderately fertile soils; may impoverish soil of phosphorus; grows in outward ring with flammable dead material in center; oils in plant increase flammability


Sources of information:

Hoshovsky, M.C. IN: Bossard et al. 2000. Invasive Plants of California's Wildlands. University of California Press. Berkeley, CA 358p.; Parsons, W.T. and E.G. Cuthbertson. 1992. Noxious Weeds of Australia. Inkata Press, Melbourne and Sydney, Australia. 692 P; Parker, R. and L. Burrill. 1991. Gorse (Ulex europaeus L.). Washington, Idaho, Oregon. Pacific Northwest Extension Publication. Pamphlet.


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

Forms impenetrable thickets excluding desirable vegetation. Colonizes nitrogen-poor soils outcompeting native plants; forms impenetrable thickets excluding desirable native vegetation. Tolerates most soil types but can suffer boron or magnesium deficiency.


Sources of information:

Hoshovsky in Bossard et al.; TNC 1989. Element Stewardship Abstract for Ulex europaeus. Accessed online at: http://tncweeds.ucdavis.edu/esadocs/ulexeuro.html May 2003.


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

B. Impedes movement of wildlife; provides habitat for some (like undesirable rabbits in Australia). Used by honey bees. No other information about use as forage found. spiny nature and dense growth forms impenetrable thicket.


Sources of information:

Parsons and Cuthbertson (see above).


Question 1.4 Impact on genetic integrity? D Other Published Material

None documented Plant has no closely related natives or non-natives in California.


Sources of information:

Hoshovsky in Bossard et al. eds. 2000. Wildland Weeds of California.


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

B; Found in infertile or disturbed sites but may invade undisturbed open areas. found in infertile or disturbed sites including sand dunes, gravel bars, fence rows, overgrazed pastures, logged and burned-over areas. May invade open areas in coastal forests per Pasquinelli, 1998.


Sources of information:

Hoshovsky, M. IN: Bossard et al. 2000. Pasquinelli, R. 1998. Exotic weeds in the North Coast State Parks. Fremontia 26 (4): 54-57.


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

rapid. explosive seed dispersal up to 5 m. from original plant.


Sources of information:

California Department of Food and Agriculture Encycloweedia as accessed on the Internet at:http://pi.cdfa.ca.gov/weedinfo/ULEX2.html June 2, 2003.


Question 2.3 Recent trend in total area infested within state? C Reviewed Scientific Publication
Describe trend:

Score = C, Stable. Gorse may have already achieved its ecoclimactic limit, at least coastally, based on climatic modelling.


Sources of information:

Fox, J.C. and S. Steinmaus. 2001. Climate prediction of an invasive plant in California: Ulex europaeus (gorse). Proceedings, California Weed Science Society 53:34-37; anecdotal observations by State Park Resource Ecologists Peter Warner, Bill Maslach, Joanne Kerbavaz and DFG Biologist Tina Fabula.


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

Score = A. Creeping roots, seeds, and re-sprouting root crowns seeds heavy, not windborne; explosive dispersal of up to 5 m with heat of sun; re-sprouts following fire, remains in seed bank for 30 years or more.


Sources of information:

The Nature Conservancy. 1989. Element Stewardship Abstract for Ulex europaeus as accessed on the Intertnet at: http://tncweeds.ucdavis.edu/esadocs/ulexeuro.html


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

C. Could be dispersed by humans for horticultural purposes, but this is currrently not likely to be an important dispersal mechanism. Although this plant was introduced by humans it is currently on the California Department of Food and Agriculture Noxious Weed List B and is not be sold in California nurseries in counties where active control measures are underway. This plant is considered undesirable in most California coastal counties.


Sources of information:

Stanton, 2002. Alternatives to invasive landscape and garden plants. CalEPPC Symposium Proceedings as accessed at: http://ucce.ucdavis.edu/freeform/ceppc/documents/2002_Symposium_Proceedings2377.pdf.
CDFA. 2003. California's Most (Un) Wanted Weeds. Noxious Times. Spring 2003. V4 #3.


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

C; is dispersed by ants and quail locally, and may be dispersed by water when growing by streams. Dispersal agentsents not likely to cause long-range dispersal. Water could act as long-range dispersal agent. Many infestations are on the immediate coast, limiting stream areas of immediate coastal drainage


Sources of information:

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

Is weedy in Australia, New Zealand, Chile, India, but in habitats similar to those invaded here. Is also in South Africa but is not considered a pest there. Is weedy in Australia, New Zealand, Chile, India, but in habitats similar to those invaded here. Is also in South Africa but is not considered a pest there.


Sources of information:

Parsons and Cuthbertson, 1992. Noxious Weeds of Australia. Inkata Press. Melbourne, Sydney, Australia. 692 p.


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? A Observational

Score = A. Currently known from 6 major ecological types and 8 minor ecological types in California. Introduced to state 1894. Is found in 6 major ecological types and 8 minor ecological types in California


Sources of information:

Personal Observations, Barry, Roye, Warner, Maslach, Fabula, Pasquinelli.


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

Score = D. Found in less than 5% of the total number of occurrences of any of the types in which it is found. Can be very dense locally.


Sources of information:

CalFlora Database, Personal observations, California State Parks 2002. Resource Condition Assessment.


Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter No
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 Yes
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned Yes
Total points: 7
Total unknowns: 1
Total score: A?

Related traits:

Seed bank can persist for 30 years; seeds have coating that is impermeable to water; burning breaks seed dormancy and seedlings abound post burn (Parsons and Cuthbertson, 1992; Hoshovsky, 1989. TNC Elem. Stewardshp Abst. accessed at http://tncweeds.ucdavis.edu/esadocs/documnts/ulexeur.pdf
http://tncweeds.ucdavis.edu/esadocs/documnts/ultncweeds.ucdavis.edu/esadocs/documnts/ulexeur.pdftncweeds.ucdavis.edu/esadocs/documnts/ulexeur.pdfhttp://tncweeds.ucdavis.edu/esadocs/documnts/ulexeur.pdfhttp://tncweeds.ucdavis.edu/esadocs/documnts/ulexeur.pdfathttp://tncweeds.ucdavis.edu/esadocs/documnts/ulexeur.pdf http://tncweeds.ucdavis.edu/esadocs/documnts/ulexeur.pdf, Hoshovsky IN: Bossard et al. 2000.).

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 scrubD, < 5%
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
chaparralD, < 5%
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairie
valley and foothill grassland
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 forestD, < 5%
North Coast coniferous forestD, < 5%
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): D

Infested Jepson Regions

Click here for a map of Jepson regions

  • Cascade Range
  • Central West
  • Northwest
  • Sierra Nevada
  • Southwest