Source: California Invasive Plant Council


URL of this page: http://www.cal-ipc.org/site/paf/552
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Cal-IPC Plant Assessment Form

For use with "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands"
by the California Invasive Plant Council and the Southwest Vegetation Management Association

Table 1. Species and Evaluator Information

Species name
(Latin binomial):
The official Latin binomial name for this species. Specify only one name here. Additional species names may go into the Synonyms field.

Genista linifolia

Synonyms:
Additional Latin binomial names for this species. Separate multiple names with a ; character. Please avoid narrative descriptions, and list only the binomial names.
Cytisus linifolius; Teline linifoli
Common names:
Common names for this species. Separate multiple names with a ; character.
Flax-leaf broom; flax broom; Dyer's greenwold; Canary Island broom; Mediterranean broom
Evaluation date:
The date(s) when this species PAF was filled out, modified, or reviewed. This is free-form text, so it may include multiple dates or other notes.
2/28/2003
Evaluator #1 John Knapp/California Islands Ecologist
The Nature Conservancy
jknapp@tnc.org
Evaluator #2 Mona Robison/Science Program Manager / JULIA PARISH PLANT CONSERVATION MANAGER
Cal-IPC / CIC
916-802-2004 / 310 510-1299 X229
rrobison@cal-ipc.org / JPARISH@CATALINACONSERVANCY.ORG
List committee members: Joe DiTomaso, Cynthia Roye, Peter Warner, Joanna Clines, Mike Kelly
Committee review date: 1/24/08
List date:
Re-evaluation date(s): January 2017
General comments
on this assessment:
Enter any additional notes about this assessment, such as factors affecting the reliability or completeness of the answers, likely affects of impacts, or research which is not specific to California but is still relevant in the evaluation of this species.
PAF was reviewed by committee in 2008 and not finished at that time. Re-evaluated in 2017 with new information. Currently a serious problem on Catalina Island. Has been reported from mainland but status and locations of those populations unknown. Will be re-evaluated if populations establish on mainland. Native origin- Western Mediterranean: Canary Islands, Morroco, Algeria, southern Spain and France. Due to its limited distribution and abundance in California, very little research has been conducted on G. linifolia, therefore, research conducted on the closely related G. monspessulana was used to fill in the gaps of lacking information for G. linifolia. G. linifolia overlaps with G. monspessulana; however, G. monspessulana has a greater native range than G. linifolia

Table 2. Criteria, Section, and Overall Scores

Overall Score

Plant scoring matrix
Based on letter scores from Sections 1 through 3 below

ImpactInvasivenessDistribution
AA BAnyHighNo Alert
AC DAnyModerateAlert
BA BA BModerateNo Alert
BA BC DModerateAlert
BC DAnyLimitedNo Alert
CAA BModerateNo Alert
CAC DLimitedNo Alert
CBAModerateNo Alert
CBB DLimitedNo Alert
CCAnyLimitedNo Alert
DAnyAnyNot ListedNo Alert

Moderate

Alert Status

Plant scoring matrix
Based on letter scores from Sections 1 through 3 below

ImpactInvasivenessDistributionAlert
AA or BC or DAlert
BA or BC or DAlert

No Alert

Documentation

The total documentation score is the average
of Documentation scores given in Table 2.

Reviewed Scientific Publication4 points
Other Published Material3 points
Observational2 points
Anecdotal1 points
Unknown or No Information0 points

3.2 out of 5

Score Documentation
1.1 Impact on abiotic ecosystem processes
Consider the impact on the natural range and variation of abiotic ecosystem processes and system-wide parameters in ways that significantly diminish the ability of native species to survive and reproduce. Alterations that determine the types of communities that can exist in a given area are of greatest concern. Examples of abiotic processes include:
- fire occurrence, frequency, and intensity;
- geomorphological changes such as erosion and sedimentation rates;
- hydrological regimes, including soil water table;
- nutrient and mineral dynamics, including salinity, alkalinity, and pH;
- light availability (e.g. when an aquatic invader covers an entire water body that would otherwise be open).

Select the one letter below that best describes this species’ most severe impact on an abiotic ecosystem process:
A. Severe, possibly irreversible, alteration or disruption of an ecosystem process.
B. Moderate alteration of an ecosystem process.
C. Minor alteration of an ecosystem process.
D. Negligible perceived impact on an ecosystem process.
U. Unknown.
B. Moderate Reviewed Scientific Publication
Impact
Section 1 Scoring Matrix
Q 1.1Q 1.2Q 1.3Q 1.4Score
AAAnyAnyA
ABA,BAnyA
ABC,D,UAnyB
AC,D,UAnyAnyB
BAAAnyA
BABAA
BAB,CB-D,UB
BAC,D,UAA
BAC,D,UB-D,UB
BBAAA
BC,D,UAAB
BB-DAB-D,UB
BB-DB-D,UAnyB
BD,UC,D,UA-BB
BD,UC,D,UC,D,UC
C-D,UAAAnyA
CBAAnyB
CA,BB-D,UAnyB
CC,D,UAnyAnyC
DA,BBAnyB
DA,BC,D,UAnyC
DCAnyAnyC
DD,UAnyAnyD
UAB,CAnyB
UB,CA,BAnyB
UB,CC,D,UAnyC
UUAnyAnyU


Four-part score
BBUD

Total Score
B
1.2 Impact on plant community
Consider the cumulative ecological impact of this species to the plant communities it invades. Give more weight to changes in plant composition, structure, and interactions that involve rare or keystone species or rare community types. Examples of severe impacts include:
- formation of stands dominated (>75% cover) by the species;
- occlusion (>75% cover) of a native canopy, including a water surface, that eliminates or degrades layers below;
- significant reduction or extirpation of populations of one or more native species.

Examples of impacts usually less than severe include:
- reduction in propagule dispersal, seedling recruitment, or survivorship of native species;
- creation of a new structural layer, including substantial thatch or litter, without elimination or replacement of a pre-existing layer;
- change in density or depth of a structural layer;
- change in horizontal distribution patterns or fragmentation of a native community;
- creation of a vector or intermediate host of pests or pathogens that infect native plant species.

Select the one letter below that best describes this species’ impact on community composition, structure and interactions:
A. Severe alteration of plant community composition, structure, or interactions.
B. Moderate alteration of plant community composition.
C. Minor alteration of community composition.
D. Negligible impact known; causes no perceivable change in community composition, structure, or interactions.
U. Unknown.
B. Moderate Other Published Material
1.3 Impact on higher trophic levels
Consider the cumulative impact of this species on the animals, fungi, microbes, and other organisms in the communities that it invades. Although a non-native species may provide resources for one or a few native species (e.g. by providing food, nesting sites, etc.), the ranking should be based on the species’ net impact on all native species. Give more weight to changes in composition and interactions involving rare or keystone species or rare community types.
Examples of severe impacts include:
- extirpation or endangerment of an existing native species or population;
- elimination or significant reduction in native species’ nesting or foraging sites, cover, or other critical resources (i.e., native species habitat), including migratory corridors.

Examples of impacts that are usually less than severe include:
- minor reduction in nesting or foraging sites, cover, etc. for native animals;
- minor reduction in habitat connectivity or migratory corridors;
- interference with native pollinators;
- injurious components, such as awns or spines that damage the mouth and gut of native wildlife species, or production of anti-digestive or acutely toxic chemical that can poison native wildlife species.

Select the one letter below that best describes this species’ impact on community composition and interactions:
A. Severe alteration of higher trophic populations, communities, or interactions.
B. Moderate alteration of higher trophic level populations, communities, or interactions.
C. Minor alteration of higher trophic level populations, communities or interactions.
D. Negligible impact; causes no perceivable change in higher trophic level populations, communities, or interactions.
E. Unknown.
E. Unknown Other Published Material
1.4 Impact on genetic integrity
Consider whether the species can hybridize with and influence the proportion of individuals with non-native genes within populations of native species. Mechanisms and possible outcomes include:
- production of fertile or sterile hybrids that can outcompete the native species;
- production of sterile hybrids that lower the reproductive output of the native species.

Select the one letter below that best describes this species’ impact on genetic integrity:
A. Severe (high proportion of individuals).
B. Moderate (medium proportion of individuals).
C. Minor (low proportion of individuals).
D. No known hybridization.
U. Unknown.
D. None Reviewed Scientific Publication
2.1 Role of anthropogenic and natural disturbance in establishment
Assess this species’ dependence on disturbance—both human and natural—for establishment in wildlands. Examples of anthropogenic disturbances include:
- grazing, browsing, and rooting by domestic livestock and feral animals;
- altered fire regimes, including fire suppression;
- cultivation;
- silvicultural practices;
- altered hydrology due to dams, diversions, irrigation, etc.;
- roads and trails;
- construction;
- nutrient loading from fertilizers, runoff, etc.

Examples of natural disturbance include:
- wildfire;
- floods;
- landslides;
- windthrow;
- native animal activities such as burrowing, grazing, or browsing.

Select the first letter in the sequence below that describes the ability of this species to invade wildlands:
A. Severe invasive potential—this species can establish independent of any known natural or anthropogenic disturbance.
B. Moderate invasive potential—this species may occasionally establish in undisturbed areas but can readily establish in areas with natural disturbances.
C. Low invasive potential—this species requires anthropogenic disturbance to establish.
D. No perceptible invasive potential—this species does not establish in wildlands (though it may persist from former cultivation).
U. Unknown.
A. Severe Other Published Material
Invasiveness
Section 2 Scoring Matrix
Total pointsScore
17-21A
11-16B
5-10C
0-4D
More than two U’sU


Total Points
15

Total Score
B
2.2 Local rate of spread with no management
Assess this species’ rate of spread in existing localized infestations where the proportion of available habitat invaded is still small when no management measures are implemented.

Select the one letter below that best describes the rate of spread:
A. Increases rapidly (doubling in <10 years)
B. Increases, but less rapidly
C. Stable
D. Declining
U. Unknown
A. Increases rapidly Other Published Material
2.3 Recent trend in total area infested within state
Assess the overall trend in the total area infested by this species statewide. Include current management efforts in this assessment and note them.

Select the one letter below that best describes the current trend:
A. Increasing rapidly (doubling in total range statewide in <10 years)
B. Increasing, but less rapidly
C. Stable
D. Declining
U. Unknown
B. Increasing less rapidly Other Published Material
2.4 Innate reproductive potential
(see Worksheet A)
Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.
A. High Other Published Material
2.5 Potential for human-caused dispersal
Assess whether this species is currently spread—or has high potential to be spread—by direct or indirect human activity. Such activity may enable the species to overcome natural barriers to dispersal that would not be crossed otherwise, or it may simply increase the natural dispersal of the species. Possible mechanisms for dispersal include:
- commercial sales for use in agriculture, ornamental horticulture, or aquariums;
- use as forage, erosion control, or revegetation;
- presence as a contaminant (seeds or propagules) in bulk seed, hay, feed, soil, packing materials, etc.;
- spread along transportation corridors such as highways, railroads, trails, or canals;
- transport on boats or boat trailers.

Select the one letter below that best describes human-caused dispersal and spread:
A. High—there are numerous opportunities for dispersal to new areas.
B. Moderate—human dispersal occurs, but not at a high level.
C. Low—human dispersal is infrequent or inefficient.
D. Does not occur.
U. Unknown.
B. Moderate Other Published Material
2.6 Potential for natural long-distance dispersal
We have chosen 1 km as the threshold of "long-distance." Assess whether this species is frequently spread, or has high potential to be spread, by animals or abiotic mechanisms that can move seed, roots, stems, or other propagules this far. The following are examples of such natural long-distance dispersal mechanisms:
- the species’ fruit or seed is commonly consumed by birds or other animals that travel long distances;
- the species’ fruits or seeds are sticky or burred and cling to feathers or hair of animals;
- the species has buoyant fruits, seeds, or other propagules that are dispersed by flowing water;
- the species has light propagules that promote long-distance wind dispersal;
- The species, or parts of it, can detach and disperse seeds as they are blown long distances (e.g., tumbleweed).

Select the one letter below that best describes natural long-distance dispersal and spread:
A. Frequent long-distance dispersal by animals or abiotic mechanisms.
B. Occasional long-distance dispersal by animals or abiotic mechanisms.
C. Rare dispersal more than 1 km by animals or abiotic mechanisms.
D. No dispersal of more than 1 km by animals or abiotic mechanisms.
U. Unknown.
C. Rare Other Published Material
2.7 Other regions invaded
Assess whether this species has invaded ecological types in other states or countries outside its native range that are analogous to ecological types not yet invaded in your state (see Worksheets B, C, and D for California, Arizona, and Nevada, respectively, in Part IV for lists of ecological types). This information is useful in predicting the likelihood of further spread within your state.

Select the one letter below that best describes the species' invasiveness in other states or countries, outside its native range.
A. This species has invaded 3 or more ecological types elsewhere that exist in your state and are as yet not invaded by this species (e.g. it has invaded Mediterranean grasslands, savanna, and maquis in southern Europe, which are analogous to California grasslands, savanna, and chaparral, respectively).
B. Invades 1 or 2 ecological types that exist but are not yet invaded in your state.
C. Invades elsewhere but only in ecological types that it has already invaded in the state.
D. Not known as an escape anywhere else.
U. Unknown.
C. Already invaded Other Published Material
3.1 Ecological amplitude/Range
(see Worksheet C)
Refer to Worksheet C and select the one letter below that indicates the number of different ecological types that this species invades.
A. Widespread—the species invades at least three major types or at least six minor types.
B. Moderate—the species invades two major types or five minor types.
C. Limited—the species invades only one major type and two to four minor types.
D. Narrow—the species invades only one minor type.
U. Unknown.
A. Widespread Other Published Material
Distribution
Section 3 Scoring Matrix
Q 3.1Q 3.2Score
AA, BA
AC,D,UB
BAA
BB,CB
BDC
CA,BB
CC,DC
DAB
DB,CC
DDD
A,BUC
C,DUD
UUU


Total Score
B
3.2 Distribution/Peak frequency
(see Worksheet C)
To assess distribution, record the letter that corresponds to the highest percent infested score entered in Worksheet C for any ecological type.
D. Very low Other Published Material

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".
Short citations may be used in this table. List full citations at end of this table.

Section 1: Impact

Reviewed Scientific Publication B Question 1.1 Impact on abiotic ecosystem processes
Consider the impact on the natural range and variation of abiotic ecosystem processes and system-wide parameters in ways that significantly diminish the ability of native species to survive and reproduce. Alterations that determine the types of communities that can exist in a given area are of greatest concern. Examples of abiotic processes include:
- fire occurrence, frequency, and intensity;
- geomorphological changes such as erosion and sedimentation rates;
- hydrological regimes, including soil water table;
- nutrient and mineral dynamics, including salinity, alkalinity, and pH;
- light availability (e.g. when an aquatic invader covers an entire water body that would otherwise be open).

Select the one letter below that best describes this species’ most severe impact on an abiotic ecosystem process:
A. Severe, possibly irreversible, alteration or disruption of an ecosystem process.
B. Moderate alteration of an ecosystem process.
C. Minor alteration of an ecosystem process.
D. Negligible perceived impact on an ecosystem process.
U. Unknown.
Identify ecosystem processes impacted:
G. linifolia alters fire regimes by burning readily, increasing fire frequency and intensity (1,2,4 & 5-G. monspessulana). Alters nutrient and water cycling in Spain (3). G. linifolia increased fire intensity of coastal scrub during the 2007 Island Fire on Catalina Island (6). Dense even aged stands, carries flame to overstory native plants (6).

Sources of information:
(1) Carroll, M.C., L.L. Laughrin, and A.C. Bromfield. 1999. Fire on the California islands: does it play a role in chaparral and closed-cone pine forest habitats? Pp. 3-87 in: F.G. Hochberg (ed.). Proceedings of the third California islands symposium. Santa Barbara, California: Santa Barbara Natural History Museum. (2) Mastro, L.W. 1993. A study on the natural history of Cytisus on Santa Catalina Island with an emphasis on biological control. in: F.G. Hochberg (ed.). Proceedings of the third California islands symposium. Santa Barbara, California: Santa Barbara Natural History Museum. (3) Gonzalez-Andres, F. and J.M. Ortiz. 1999. Specificity of rhizobia nodulating Genista monspessulana and Genista linifolia in vitro and in field situations. Arid Soil Research and Rehabilitation 13(3): 223-237. (4) Anonymous. 2001. A comprehensive broom and gorse biological control effort. CalEPPC News 9(2): 3-6. (5) Bossard, C.C. 2000. Genista monspessulana. Bossard, C.C., J.M. Randall, and M.C. Hoshovsky, (eds). In, Invasive plants of California’s wildlands. Pp. 203-208. Berkeley, California: University of California Press. (6) Knapp, J. J. Personal observation on Catalina Island during 2007 Island Fire.

Other Published Material B Question 1.2 Impact on plant community composition,
structure, and interactions
Consider the cumulative ecological impact of this species to the plant communities it invades. Give more weight to changes in plant composition, structure, and interactions that involve rare or keystone species or rare community types. Examples of severe impacts include:
- formation of stands dominated (>75% cover) by the species;
- occlusion (>75% cover) of a native canopy, including a water surface, that eliminates or degrades layers below;
- significant reduction or extirpation of populations of one or more native species.

Examples of impacts usually less than severe include:
- reduction in propagule dispersal, seedling recruitment, or survivorship of native species;
- creation of a new structural layer, including substantial thatch or litter, without elimination or replacement of a pre-existing layer;
- change in density or depth of a structural layer;
- change in horizontal distribution patterns or fragmentation of a native community;
- creation of a vector or intermediate host of pests or pathogens that infect native plant species.

Select the one letter below that best describes this species’ impact on community composition, structure and interactions:
A. Severe alteration of plant community composition, structure, or interactions.
B. Moderate alteration of plant community composition.
C. Minor alteration of community composition.
D. Negligible impact known; causes no perceivable change in community composition, structure, or interactions.
U. Unknown.
Identify type of impact or alteration:
G. linifolia destroys community integrity (1). Out competes native vegetation even on infertile soils (2-G. monspessulana, 3, 5). Displaces native flora (2-G. monspessulana, 3). Forms dense monostands (2-G. monspessulana, 3,4) that commonly reach 100% cover and extripate populations of native species (3). G. linifolia grows rapidly (2-G. monspessulana, 3) and shades out native species (2-G. monspessulana, 3). G. linifolia grows in close proximity to several listed and endemic plant species and in riparian habitat of listed wildlife species on Catalalina Island (3). G. linifolia alters island chaparral, island woodland, and oakwoodland understory by creating a thick wall of vegetation from the ground to canopy (3). Mutualistic relationship with nitrogen-fixing bacteria found in small nodules on roots (2). Fire dervived increase in the root:above-ground biomass ration allows resprouters to reach higher folia concentrations, even if nutrient uptake efficiency or soil fertility remain unchanged (5).

Sources of information:
1) Mastro, L.W. 1987. Effects of Dyer’s Greenwold, Cytisus linifolius (Fabaceae) on the native vegetation of Santa Catalina Island. Crossosoma, 13(6):2-6. (2) Bossard, C.C. 2000. Genista monspessulana. Bossard, C.C., J.M. Randall, and M.C. Hoshovsky, (eds). In, Invasive plants of California’s wildlands. Pp. 203-208. Berkeley, California: University of California Press. (3) Knapp, J.J. 2004. Catalina Island Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished. (4) McClintock, E. 1979. The weedy brooms – where did they come from? Fremontia 6(4): 15-17. (5) Carreira, J.A. and F.X. Niell. 1992. Plant nutrient changes in a semi-arid Mediterranean shrubland after fire. Journal of Vegetation Science 3(4): 457-466.

Other Published Material U Question 1.3 Impact on higher trophic levels
Consider the cumulative impact of this species on the animals, fungi, microbes, and other organisms in the communities that it invades. Although a non-native species may provide resources for one or a few native species (e.g. by providing food, nesting sites, etc.), the ranking should be based on the species’ net impact on all native species. Give more weight to changes in composition and interactions involving rare or keystone species or rare community types.
Examples of severe impacts include:
- extirpation or endangerment of an existing native species or population;
- elimination or significant reduction in native species’ nesting or foraging sites, cover, or other critical resources (i.e., native species habitat), including migratory corridors.

Examples of impacts that are usually less than severe include:
- minor reduction in nesting or foraging sites, cover, etc. for native animals;
- minor reduction in habitat connectivity or migratory corridors;
- interference with native pollinators;
- injurious components, such as awns or spines that damage the mouth and gut of native wildlife species, or production of anti-digestive or acutely toxic chemical that can poison native wildlife species.

Select the one letter below that best describes this species’ impact on community composition and interactions:
A. Severe alteration of higher trophic populations, communities, or interactions.
B. Moderate alteration of higher trophic level populations, communities, or interactions.
C. Minor alteration of higher trophic level populations, communities or interactions.
D. Negligible impact; causes no perceivable change in higher trophic level populations, communities, or interactions.
E. Unknown.
Identify type of impact or alteration:
Genista monspessulana can be toxic to livestock if ingested in large quantities but no information on G. linifolia. Dense thickets can inhibit the movement of wildlife (3, 4), including island fox, Catalina quail, and mule deer (5).

Sources of information:
(1) Blood, K. Date unknown. Environmental Weeds: a field guide for SE Australia (2) Bossard, C.C. 2000. Genista monspessulana. Bossard, C.C., J.M. Randall, and M.C. Hoshovsky, (eds). In, Invasive plants of California’s wildlands. Pp. 203-208. Berkeley, California: University of California Press. (3) McClintock, E. 1979. The weedy brooms – where did they come from? Fremontia 6(4): 15-17. (4) Hoshovsky, M. 1986. Element stewardship abstract: Cytisus scoparius (Scotch broom), Cytisus monspessulanus (French broom), and Spartium junceum (Spanish broom). The Nature Conservancy, Washington, D.C. (5) Knapp, J.J. 2004. Catalina Island Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished.

Reviewed Scientific Publication D Question 1.4 Impact on genetic integrity
Consider whether the species can hybridize with and influence the proportion of individuals with non-native genes within populations of native species. Mechanisms and possible outcomes include:
- production of fertile or sterile hybrids that can outcompete the native species;
- production of sterile hybrids that lower the reproductive output of the native species.

Select the one letter below that best describes this species’ impact on genetic integrity:
A. Severe (high proportion of individuals).
B. Moderate (medium proportion of individuals).
C. Minor (low proportion of individuals).
D. No known hybridization.
U. Unknown.
Identify impacts:
No hybridization is known to occur. No native California taxa are in the genus Genista.

Sources of information:
Hickman, J.C. (ed.). 1993. The Jepson manual of higher plants of California. P. 609. University of California Press, Berkeley.

Section 2: Invasiveness

Other Published Material A Question 2.1 Role of anthropogenic and natural disturbance
in establishment
Assess this species’ dependence on disturbance—both human and natural—for establishment in wildlands. Examples of anthropogenic disturbances include:
- grazing, browsing, and rooting by domestic livestock and feral animals;
- altered fire regimes, including fire suppression;
- cultivation;
- silvicultural practices;
- altered hydrology due to dams, diversions, irrigation, etc.;
- roads and trails;
- construction;
- nutrient loading from fertilizers, runoff, etc.

Examples of natural disturbance include:
- wildfire;
- floods;
- landslides;
- windthrow;
- native animal activities such as burrowing, grazing, or browsing.

Select the first letter in the sequence below that describes the ability of this species to invade wildlands:
A. Severe invasive potential—this species can establish independent of any known natural or anthropogenic disturbance.
B. Moderate invasive potential—this species may occasionally establish in undisturbed areas but can readily establish in areas with natural disturbances.
C. Low invasive potential—this species requires anthropogenic disturbance to establish.
D. No perceptible invasive potential—this species does not establish in wildlands (though it may persist from former cultivation).
U. Unknown.
Describe role of disturbance:
Planted as an ornamental in Australia (1) and on Catalina Island (5). Brooms colonize open disturbed sites, roadsides, and pastures, and can invade undisturbed (4) grasslands, coastal scrub, oak woodlands, chaparral, and open forests (2, 5). Game trails (3), road making, pig rooting, fire, vegetative disturbance can lead to establishment (4,5).

Sources of information:
1) Blood, K. Date unknown. Environmental Weeds: a field guide for SE Australia. NE. (2) Anonymous. 2001. A comprehensive broom and gorse biological control effort. CalEPPC News 9(2): 3-6. (3) Mastro, L.W. 1990. A study on the natural history of Cytisus (Fabaceae) on Santa Catalina Island with an emphasis on biological control. Masters thesis, California State University Long Beach. Pp. 1-77. (4) Anonymous. 2002. Broom: Montpellier broom (Genista monspessulana L.) and English broom (Cytisus scoparius L.). Department of Primary Industries, Water and Environment. http://www.dpiwe.tas.gov.au/inter.nsf/WebPages/RPIO-4ZZ72G?open. (5) Knapp, J.J. 2004. Catalina Island Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished.

Other Published Material A Question 2.2 Local rate of spread with no management
Assess this species’ rate of spread in existing localized infestations where the proportion of available habitat invaded is still small when no management measures are implemented.

Select the one letter below that best describes the rate of spread:
A. Increases rapidly (doubling in <10 years)
B. Increases, but less rapidly
C. Stable
D. Declining
U. Unknown
Describe rate of spread:
eeds are dispersed explosively up to 3-4 meters from individual plants by shattering (1,2-G. monspessulana). On Catalina Island, existing populations annually produce tens of thousands of new seedlings, and many young new satelite populations are detected (3). On Catalina Island, one population was discovered as escaped from cultivation in 1923 (4), by 1967 it became abundantly established on the SE half of the Island (5), and in 2003, 824 populations were recorded covering 40,487,825 ft2 (3).

Sources of information:
1) Anonymous. No date. Different fates of island brooms: contrasting evolustion in Adenocarpus, Gensta and Teline (Genisteae, Leguminosae) in the Canary Islands and Madeira. Botanical Journal of the Linnean Society. Pp. 260-278 (2) Bossard, C.C. 2000. Genista monspessulana. Bossard, C.C., J.M. Randall, and M.C. Hoshovsky, (eds). In, Invasive plants of California’s wildlands. Pp. 203-208. Berkeley, California: University of California Press. (3) Knapp, J.J. 2004. Catalina Island Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished. (4) Millspaugh, C.F. and Nuttall, L.W. 1923. Flora of Santa Catalina Island. P. 140. Field Museum of Natural History, Botany v.5. Chicago. (5) Thorne, R.F. 1967. A flora of Santa Catalina Island, California. Aliso, 6(3):1-77.

Other Published Material B Question 2.3 Recent trend in total area infested within state
Assess the overall trend in the total area infested by this species statewide. Include current management efforts in this assessment and note them.

Select the one letter below that best describes the current trend:
A. Increasing rapidly (doubling in total range statewide in <10 years)
B. Increasing, but less rapidly
C. Stable
D. Declining
U. Unknown
Describe trend:
Two known locations in California, Santa Catalina Island (40,487,825 square feet invaded (2)) and Romero Canyon, Santa Barbara County (1). G. linifolia IS THE #1 PRIORITY species controlled on SANTA Catalina Island (2, PARISH, PERS. COMM.), AND SPENDS 50% OF MANAGEMENT RESOURCES CONTROLLING THIS SPECIES, AND OCCUPIES 1,984 ACRES AS OF 2016 COMPRISING 2,547 INFESTATIONS (PARISH, PERS. COMM.)

Sources of information:
(1) Mastro, L.W. 1993. A study on the natural history of Cytisus on Santa Catalina Island with an emphasis on biological control. in: F.G. Hochberg (ed.). Proceedings of the third California islands symposium. Santa Barbara, California: Santa Barbara Natural History Museum. (2) Knapp, J.J. 2004. Catalina Island Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished. PARISH, J. 2017. PERSONAL COMMUNICATION.

Other Published Material A Question 2.4 Innate reproductive potential
Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.
Describe key reproductive characteristics:
Perennial shrub with deep tap root that reproduces by seed (4), but G. monspessulana and Cytisus scoparius has been propagated by cuttings (11). Fire stimulates prolific germination (1). Reproductive stage reached by two years (2), but individuals have been observed to flower within the first year (3). Mutualistic relationship with nitrogen-fixing bacteria found in small nodules on roots (5-G. monspessulana). Medium sized plants of G. monspessulana can produce 8,000 seeds per year and have long-lived seed banks, and become reproductive by 2-3 years (9, 5-G. monspessulana). Seeds remain viable in the soil for over 5 years, and plants live between 10-15 years (5-G. monspessulana, 10), while others believe seeds can remain viable for nearly century (7,11,12), with stored seed of G. monspessulana remaining viable after 80 years (10). Resprouts readily after being cut and sometimes after fire (6,5-G. monspessulana). Most brooms are drought resistant (8). Broom species can produce 30,000-100,000 seeds per square meter (8), with an individual G. linifolia producing 53,200 seeds (9). G. linifolia seeds had 95% germination after 1.5 years in lab experiments (9).

Sources of information:
1) Mastro, L.W. 1993. A study on the natural history of Cytisus on Santa Catalina Island with an emphasis on biological control. in: F.G. Hochberg (ed.). Proceedings of the third California islands symposium. Santa Barbara, California: Santa Barbara Natural History Museum. (2) Brown, K. and K. Brooks. 2002. Bushland weeds – a practical guide to their management. Pp. 86-87. Environmental Weeds Action Network. Greenwood, Australia. (3) Knapp, J.J. 2004. Catalina Island Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished. (4) Gonzalez-Andres, F. and J.M. Ortiz. 1999. Specificity of rhizobia nodulating Genista monspessulana and Genista linifolia in vitro and in field situations. Arid Soil Research and Rehabilitation 13(3): 223-237. (5) Bossard, C.C. 2000. Genista monspessulana. Bossard, C.C., J.M. Randall, and M.C. Hoshovsky, (eds). In, Invasive plants of California’s wildlands. Pp. 203-208. Berkeley, California: University of California Press. (6) Knapp, J.J. 2002. Personal observation. (7) Steinmaus, S. 2002. Personal communication. (8) Anonymous. 2001. A comprehensive broom and gorse biological control effort. CalEPPC News 9(2): 3-6. (9) Mastro, L.W. 1990. A study on the natural history of Cytisus (Fabaceae) on Santa Catalina Island with an emphasis on biological control. Masters thesis, California State University Long Beach. Pp. 1-77. (10) Anonymous. 2002. Broom: Montpellier broom (Genista monspessulana L.) and English broom (Cytisus scoparius L.). Department of Primary Industries, Water and Environment. http://www.dpiwe.tas.gov.au/inter.nsf/WebPages/RPIO-4ZZ72G?open. (11) Comings, A. 1994. Fighting invaders with bare hands. Fremontia 22(3): 30-31. (12) Hoshovsky, M. 1986. Element stewardship abstract: Cytisus scoparius (Scotch broom), Cytisus monspessulanus (French broom), and Spartium junceum (Spanish broom). The Nature Conservancy, Washington, D.C.

Other Published Material B Question 2.5 Potential for human-caused dispersal
Assess whether this species is currently spread—or has high potential to be spread—by direct or indirect human activity. Such activity may enable the species to overcome natural barriers to dispersal that would not be crossed otherwise, or it may simply increase the natural dispersal of the species. Possible mechanisms for dispersal include:
- commercial sales for use in agriculture, ornamental horticulture, or aquariums;
- use as forage, erosion control, or revegetation;
- presence as a contaminant (seeds or propagules) in bulk seed, hay, feed, soil, packing materials, etc.;
- spread along transportation corridors such as highways, railroads, trails, or canals;
- transport on boats or boat trailers.

Select the one letter below that best describes human-caused dispersal and spread:
A. High—there are numerous opportunities for dispersal to new areas.
B. Moderate—human dispersal occurs, but not at a high level.
C. Low—human dispersal is infrequent or inefficient.
D. Does not occur.
U. Unknown.
Identify dispersal mechanisms:
Contaminated soil (1,6), road grading equipment, maintenance machinery, and mud (2-G. monspessulana, 3,6). Other brooms are widely planted as ornamentals but G. linifolia is not commonly sold (1,4). Feral animals may disperse G. linifolia seeds (5). Vehicles, footwear, pig rooting and the digestive tracts of horses and other animals, and short-scale dispersal through microsites such as fallen trees and animal tracts (6).

Sources of information:
(1) Knapp, J.J. 2004. Catalina Island Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished. (2) Bossard, C.C. 2000. Genista monspessulana. Bossard, C.C., J.M. Randall, and M.C. Hoshovsky, (eds). In, Invasive plants of California’s wildlands. Pp. 203-208. Berkeley, California: University of California Press. (3) Saldana, H. 2002. Personal communication. (4) Anonymous. 2001. A comprehensive broom and gorse biological control effort. CalEPPC News 9(2): 3-6. (5) Mastro, L.W. 1990. A study on the natural history of Cytisus (Fabaceae) on Santa Catalina Island with an emphasis on biological control. Masters thesis, California State University Long Beach. Pp. 1-77. (6) Anonymous. 2002. Broom: Montpellier broom (Genista monspessulana L.) and English broom (Cytisus scoparius L.). Department of Primary Industries, Water and Environment. http://www.dpiwe.tas.gov.au/inter.nsf/WebPages/RPIO-4ZZ72G?open.

Other Published Material C Question 2.6 Potential for natural long-distance dispersal
We have chosen 1 km as the threshold of "long-distance." Assess whether this species is frequently spread, or has high potential to be spread, by animals or abiotic mechanisms that can move seed, roots, stems, or other propagules this far. The following are examples of such natural long-distance dispersal mechanisms:
- the species’ fruit or seed is commonly consumed by birds or other animals that travel long distances;
- the species’ fruits or seeds are sticky or burred and cling to feathers or hair of animals;
- the species has buoyant fruits, seeds, or other propagules that are dispersed by flowing water;
- the species has light propagules that promote long-distance wind dispersal;
- The species, or parts of it, can detach and disperse seeds as they are blown long distances (e.g., tumbleweed).

Select the one letter below that best describes natural long-distance dispersal and spread:
A. Frequent long-distance dispersal by animals or abiotic mechanisms.
B. Occasional long-distance dispersal by animals or abiotic mechanisms.
C. Rare dispersal more than 1 km by animals or abiotic mechanisms.
D. No dispersal of more than 1 km by animals or abiotic mechanisms.
U. Unknown.
Identify dispersal mechanisms:
Seeds are transported by birds on the Canary Islands (1,3,4-broom species), and California quail are suspected of dispersing broom seeds (2). Ants, animals, river water and rain wash also disperse seeds (,43-G. monspessulana). Once in a stream bed, G. linifolia has been found further downstream in areas where infestations have never been known to occur (5). However, most of these vectors are <1km dispersal and therefore do not represent significant means of long-distance spread in California.

Sources of information:
(1) Anonymous. No date. Different fates of island brooms: contrasting evolustion in Adenocarpus, Gensta and Teline (Genisteae, Leguminosae) in the Canary Islands and Madeira. Botanical Journal of the Linnean Society. Pp. 260-278. NEED MORE INFO. (2) Steinmaus, S. 2002. Personal communication. (3) Bossard, C.C. 2000. Genista monspessulana. Bossard, C.C., J.M. Randall, and M.C. Hoshovsky, (eds). In, Invasive plants of California’s wildlands. Pp. 203-208. Berkeley, California: University of California Press. (4) Hoshovsky, M. 1986. Element stewardship abstract: Cytisus scoparius (Scotch broom), Cytisus monspessulanus (French broom), and Spartium junceum (Spanish broom). The Nature Conservancy, Washington, D.C. (5) Knapp, J.J. 2004. Catalina Island Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished.

Other Published Material C Question 2.7 Other regions invaded
Assess whether this species has invaded ecological types in other states or countries outside its native range that are analogous to ecological types not yet invaded in your state (see Worksheets B, C, and D for California, Arizona, and Nevada, respectively, in Part IV for lists of ecological types). This information is useful in predicting the likelihood of further spread within your state.

Select the one letter below that best describes the species' invasiveness in other states or countries, outside its native range.
A. This species has invaded 3 or more ecological types elsewhere that exist in your state and are as yet not invaded by this species (e.g. it has invaded Mediterranean grasslands, savanna, and maquis in southern Europe, which are analogous to California grasslands, savanna, and chaparral, respectively).
B. Invades 1 or 2 ecological types that exist but are not yet invaded in your state.
C. Invades elsewhere but only in ecological types that it has already invaded in the state.
D. Not known as an escape anywhere else.
U. Unknown.
Identify other regions:
Considered naturalized in Australia in 1887, and then categorized as a noxious weed in 1900 (1,2,3), and is the second most important broom species targeted for biocontrol (4).

Sources of information:
(1) Blood, K. Date unknown. Environmental Weeds: a field guide for SE Australia. (2) Harden, G.J. (ed.). 1990. Flora of New South Wales, Vol. 2. New South Wales University Press: Kensington, Australia. (3) Panetta, F.D., Groves, R.H. and Shepherd, R.C. 1998. The biology of Australian Weeds, Vol. 2. R.G. and F.J. Richardson: Meredith, Australia. (4) Syrett, P., Fowler, S.V., Coombs, E.M., Hosking, J.R., Markin, G.P., Paynter, Q.E. and Sheppard, A.W. 1999. The potential for biological control of Scotch broom (Cytisus scoparius) (Fabaceae) and related weedy species. Biocontrol News and Information, 20(1):17-33.

Section 3: Distribution

Other Published Material A Question 3.1 Ecological amplitude/Range
Refer to Worksheet C and select the one letter below that indicates the number of different ecological types that this species invades.
A. Widespread—the species invades at least three major types or at least six minor types.
B. Moderate—the species invades two major types or five minor types.
C. Limited—the species invades only one major type and two to four minor types.
D. Narrow—the species invades only one minor type.
U. Unknown.
Describe ecological amplitude, identifying date of source information and approximate date of introduction to the state, if known:
No data on habitats invaded was found for other locations in California other than on Catalina Island (2). G. linifolia was first planted at the Descanso Hotel in the early 1920's, and by 1938 it was considered naturalized on Santa Catalina Island (1). The following is the percentage of habitats invaded on Santa Catalina Island: bare-0.42%, chaparral-1.6%, coastal scrub-0.6%, coastal scrub/grassland-6.7%, grassland-0.01%, riparian-1.02%, nearly 100 populations recorded in non-native communities (2), AND ISLAND WOODLAND (PARISH). G. monspessulana invades coastal plains, mountain slopes, grasslands, and open canopy forests, and disturbed places such as: river banks, road cuts, and forest clear cuts (3). G. monspessulana also invades coast live oak (4), valley grasslands (5), foothill oak woodland (5).

Sources of information:
(1) Mastro, L.W. 1987. Effects of Dyer’s Greenwold, Cytisus linifolius (Fabaceae) on the native vegetation of Santa Catalina Island. Crossosoma, 13(6):2-6. (2) Knapp, J.J. 2004. Catalina Island Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished. (3) Bossard, C.C. 2000. Genista monspessulana. Bossard, C.C., J.M. Randall, and M.C. Hoshovsky, (eds). In, Invasive plants of California’s wildlands. Pp. 203-208. Berkeley, California: University of California Press. (4) Archbald, G. 1994. A French broom control method. CalEPPC News. 2(1): 4-6. (5) Schwartz, M.W., Porter, D.J., Randall, J.M. and Lyons, K.E. 1996. Impact of nonindigenous plants. Sierra Nevada Ecosystem Project: Final report to Congress, vol. II, Assessments and scientific basis for management options. Davis: University of California, Centers for Water and Wildland Resources. Pp.1203-1226.

Other Published Material D Question 3.2 Distribution/Peak frequency
To assess distribution, record the letter that corresponds to the highest percent infested score entered in Worksheet C for any ecological type.
Describe distribution:
No data on habitats invaded was found for other locations in California other than on Catalina Island (1). PARISH, J. 2017. PERSONAL COMMUNICATION.

Sources of information:
(1) Knapp, J.J. 2004. Catalina Island Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished.

References

List full citations for all references used in the PAF (short citations such as DiTomaso and Healy 2007 may be used in table above). Websites should include the name of the organization and the date accessed. Personal communications should include the affiliation of the person providing the observation. Enter each reference on a separate line.
See Sources of Information sections above.

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes, 1 points
Dense infestations produce >1,000 viable seed per square meter Yes, 2 points
Populations of this species produce seeds every year. Yes, 1 points
Seed production sustained over 3 or more months within a population annually Yes, 1 points
Seeds remain viable in soil for three or more years Yes, 2 points
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, 1 points
Total points: 8
Total unknowns: 1
Total score: A
Scoring Criteria for Worksheet A
A. High reproductive potential (6 or more points).
B. Moderate reproductive potential (4-5 points).
C. Low reproductive potential (3 points or less and less than 3 Unknowns).
U. Unknown (3 or fewer points and 3 or more Unknowns).
Note any related traits:
Return to Table 2

Worksheet B - Arizona Ecological Types is not included here


Worksheet C - California Ecological Types
 
(sensu Holland 1986)

Major Ecological Types Minor Ecological Types Code
A means >50% of type occurrences are invaded;
B means >20% to 50%;
C means >5% to 20%;
D means present but ≤5%;
U means unknown (unable to estimate percentage of occurrences invaded)
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
estuaries
Dunescoastal
desert
interior
Scrub and Chaparralcoastal bluff scrub
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, coastal prairieD. < 5%
Meadows, and other Herbvalley and foothill grassland
CommunitiesGreat 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)D. < 5%
Woodlandcismontane woodlandU. Unknown
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)   D
Return to Table 2

Addendum J - Jepson Regions Infested
 
Click here for a map of Jepson regions

Infested Jepson Regions:
Check the boxes to indicate the Jepson floristic provinces in which this species is found.














Addendum L - External Links & Resources

Calflora Plant Profile:
The Calflora Plant Profile for this species.
CalWeedMapper:
Load CalWeedMapper with this species already selected.