Plant Assessment Form
More Chrysanthemoides monilifera ssp. monilifera resources
Chrysanthemoides monilifera ssp. monilifera
Synonyms: Osteospermum moniliferum
Common Names: boneseed; Higgin's curse; jungle flower;
Evaluated on: 30-Dec-16
List committee review date: 26/01/2017
Re-evaluation date:
Evaluator(s)
Lynn Sweet/Associate Research Specialist
University of California, Riverside
75-080 Frank Sinatra Dr., Palm Desert, CA 92211
760-834-0594
lynn.c.sweet@gmail.com
Mona Robison/Science Program Manager
Cal-IPC
916-802-2004
rrobison@cal-ipc.org
List committee members
Jutta Burger
Naomi Fraga
Denise Knapp
Chris McDonald
Ron Vanderhoff
John Knapp
Elizabeth Brusati
General Comments
From the evaluator:
The subspecies of Chrysanthemoides that we have here in California, according to Calflora and local experts, is Chrysanthemoides monilifera ssp. monilifera, which is referred to as "boneseed." Chrysanthemoides monilifera ssp. rotundata is the subspecies that Australians refer to as "bitou bush" therefore this common name should not be used for this species.
Key differences from CRC Weed Management Guide:
"In contrast to the closely related bitou bush (Chrysanthemoides monilifera
ssp. rotundata) which has a sprawling habit, boneseed is an erect shrub."
----
Information used to prepare the PAF should be based on "ecological impacts on the species' behavior in ecosystems within the state; however, species behavior elsewhere within similar ecosystems can be used when a non-native species previously unknown within a state is newly discovered and requires judgement as to whether it qualifies for rapid response (Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands)." Impacts in California are currently low because this species is early in the invasion curve. Observed impacts from the only two extant CA populations (Orange County) are uncertain, as the species currently covers only about 1 acre gross and is primarily in urban edge habitat. However, since the species has naturalized in California impacts from other regions were used to assess the potential impacts.
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|
Overall Score ?
Plant scoring matrix
Based on letter scores from Sections 1 through 3 below
| Impact | Invasiveness | Distribution | | |
| A | A B | Any | High | No Alert |
| A | C D | Any | Moderate | Alert |
| B | A B | A B | Moderate | No Alert |
| B | A B | C D | Moderate | Alert |
| B | C D | Any | Limited | No Alert |
| C | A | A B | Moderate | No Alert |
| C | A | C D | Limited | No Alert |
| C | B | A | Moderate | No Alert |
| C | B | B D | Limited | No Alert |
| C | C | Any | Limited | No Alert |
| D | Any | Any | Not Listed | No Alert |
Moderate
|
Alert Status ?
Plant scoring matrix
Based on letter scores from Sections 1 through 3 below
| Impact | Invasiveness | Distribution | Alert |
| A | A or B | C or D | Alert |
| B | A or B | C or D | Alert |
Alert
|
Documentation ?
The total documentation score is the average
of Documentation scores given in Table 2.
| Reviewed Scientific Publication | 4 points |
| Other Published Material | 3 points |
| Observational | 2 points |
| Anecdotal | 1 points |
| Unknown or No Information | 0 points |
3.5 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.
|
C. Minor |
Reviewed Scientific Publication |
Impact?
| Section 1 Scoring Matrix |
|---|
| Q 1.1 | Q 1.2 | Q 1.3 | Q 1.4 | Score |
| A | A | Any | Any | A |
| A | B | A,B | Any | A |
| A | B | C,D,U | Any | B |
| A | C,D,U | Any | Any | B |
| B | A | A | Any | A |
| B | A | B | A | A |
| B | A | B,C | B-D,U | B |
| B | A | C,D,U | A | A |
| B | A | C,D,U | B-D,U | B |
| B | B | A | A | A |
| B | C,D,U | A | A | B |
| B | B-D | A | B-D,U | B |
| B | B-D | B-D,U | Any | B |
| B | D,U | C,D,U | A-B | B |
| B | D,U | C,D,U | C,D,U | C |
| C-D,U | A | A | Any | A |
| C | B | A | Any | B |
| C | A,B | B-D,U | Any | B |
| C | C,D,U | Any | Any | C |
| D | A,B | B | Any | B |
| D | A,B | C,D,U | Any | C |
| D | C | Any | Any | C |
| D | D,U | Any | Any | D |
| U | A | B,C | Any | B |
| U | B,C | A,B | Any | B |
| U | B,C | C,D,U | Any | C |
| U | U | Any | Any | U |
Four-part score
CBCD
Total Score
B
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| 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 |
Reviewed Scientific Publication |
| 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.
|
C. Minor |
Reviewed Scientific Publication |
| 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 |
Other Published Material |
|
| 2.1 |
?Role of anthropogenic and natural disturbance in establishment
Assess dependence on disturbance, both human and natural, for establishment of this species 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.
|
B. Moderate |
Reviewed Scientific Publication |
Invasiveness?
| Section 2 Scoring Matrix |
| Total points | Score |
| 17-21 | A |
| 11-16 | B |
| 5-10 | C |
| 0-4 | D |
| More than two U's | U |
Total Points
17
Total Score
A
|
| 2.2 |
?Local rate of spread with no management
Assess 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
|
B. Increases less rapidly |
Reviewed Scientific Publication |
| 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 |
Observational |
| 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 |
Reviewed Scientific Publication |
| 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.
|
A. Frequent |
Reviewed Scientific Publication |
| 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.
|
A. Invades 3 or more ecological types |
Reviewed Scientific Publication |
|
| 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.
|
C. Limited |
Other Published Material |
Distribution?
| Section 3 Scoring Matrix |
| Q 3.1 | Q 3.2 | Score |
| A | A, B | A |
| A | C,D,U | B |
| B | A | A |
| B | B,C | B |
| B | D | C |
| C | A,B | B |
| C | C,D | C |
| D | A | B |
| D | B,C | C |
| D | D | D |
| A,B | U | C |
| C,D | U | D |
| U | U | U |
Total Score
C
|
| 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 |
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?
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.
|
C
Reviewed Scientific Publication
|
Identify ecosystem processes impacted:
There is some disagreement about whether this species increases fire frequency or intensity, as listed on the (Australia) Queensland Biosecurity site, but fire can kill adult plants, seedlings and seeds, and has been used to control the species, according to a recent status review (1, 2). This species does regenerate readily after fires in some situations (3).
No other information was found specifically for the subspecies, C. monilifera ssp. monilifera, however, the more well-studied subspecies, C. monilifera ssp. rotundata has some documented impacts on soils, listed below.
Nutrient and mineral dynamics may be impacted by C. monilifera ssp. rotundata, as rates of decomposition between this species and native sclerophyllous species in Australia were shown to be very different, where the former cycles much faster. (4)
Nitrogen cycling was shown to be altered by this species in a separate study by the same authors in Australia. (5)
Allelopathic properties were also found for this plant, and the non-polar chemicals were isolated from plant leaves, which could interfere with plant-microbe interactions. The authors hypothesized that the addition of these chemicals to the soil could drive community changes. (6)
Sources of information:
(1) Weiss et al. (2008)
(2) Queensland Biosecurity Edition
(3) Parsons and Cuthbertson (2001)
(4) Lindsay & French (2004)
(5) Lindsay & French (2005)
(6) Ens et al. (2009)
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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.
|
B
Reviewed Scientific Publication
|
Identify type of impact or alteration:
Observed impacts from the only two extant California populations (Orange County) are uncertain, as the species currently covers only about 1 acre gross and is primarily in urban edge habitat. (1)
This species has been known to form monocultures and reduces diversity of above-ground vegetation as well as the seedbank in studies in Australia. (2)
The species competes well with existing vegetation and can overtop and dominate the native community.
Both this and the other subspecies present in Australia (rotundata) are Weeds of National Significance due to threats including to species of special concern, including 14 at risk, as reported, solely due to this species. (3,4)
There is some evidence that this species may exude allelopathic compounds that suppress growth by other species. (5)
Sources of information:
(1) Vanderhoff, R. 2017. Personal communication.
(2) Thomas et al. (2005)
(3) Weiss et al. (2008)
(4) Parsons, W.T., & Cuthbertson E.G.. (2001)
Al Harun et al. (2014)
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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.
|
C
Reviewed Scientific Publication
|
Identify type of impact or alteration:
This species is known to reduce the amount of preferred forage plants for native bird species post-invasion. (1)
This species does provide forage for some native birds and marsupials in Australia, as well as some feral and farm species. (2)
Sources of information:
(1) Parsons, W.T., & Cuthbertson E.G.. (2001)
(2) Weiss et al. (2008)
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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.
|
D
Other Published Material
|
There are no native species in the Chrysanthemoides genus in California. (1)
This species is in the Calenduleae Tribe within Asteraceae, and the other species in this tribe are also not present in California (primarily African/South African origin). (1,2)
Sources of information:
(1) Calflora 2016
(2) USDA GRIN
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| Section 2: Invasiveness |
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.
|
B
Reviewed Scientific Publication
|
Describe role of disturbance:
California populations are still emergent, but plants are primarily in semi-cultivated habitats with some plants receiving supplemental irrigation or urban runoff. I would define the CA infestations as primarily disturbed habitat at present. (1)
For the species in Australia, Weiss 2008, states that while fire promotes seedling emergence, no disturbance is necessary and this species can readily colonize disturbed sites. (2)
This species is in fact suppressed by soil cultivation, trampling and grazing. (3)
CA POPULATIONS ARE STILL EMERGENT, BUT PLANTS ARE PRIMARILY IN SEMI-CULTIVATED HABITATS WITH SOME PLANTS RECEIVING SUPPLEMENTAL IRRIGATION OR URBAN RUNOFF. I WOULD DEFINE THE CA INFESTATIONS AS PRIMARILY DISTURBED HABITAT AT PRESENT. RV
Sources of information:
(1) Vanderhoff, R. 2017. Personal communication.
(2) Weiss et al. (2008)
(3) Parsons, W.T., & Cuthbertson E.G.. (2001)
|
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
|
B
Reviewed Scientific Publication
|
Describe rate of spread:
At the principal/largest infestation (Aliso Canyon, South Orange County) observations only span four years since the detection. However, plants were mature and well established, indicating a best guess of the colony being extant for 10-15 years. At present the colony occupies a gross area of .75 acre.
One population has spread 500-600 meters in 10 years, noted to be a moderate rate of spread for a woody perennial shrub.
Management notes for Australia for this species warn land managers that this species can expand reestablish after fire in certain cases, and the population can "expand as it quickly re-established a massive seedbank."
"No management activity has been planned or executed at the two Orange County colonies. The plants are spread across a multitude of private property owners as well as city and probably state property."
A case study detailed in the management guide: "Boneseed expanded its range rapidly after bushfires in 1985 in the You Yangs Regional Park, south-west of Melbourne. Before the fires, boneseed was scattered throughout the park. The fires were widespread, burning 85 per cent of the park, and they triggered the mass germination of huge numbers of boneseed seedlings. Within three years of the fire, the boneseed infestation became dense and widespread in the You Yangs, and now impacts upon 1300 hectares of the 2000 hectare park. Boneseed now dominates the middle-storey vegetation in the areas that were burned." (2)
It is thought to have been introduced to mainland Australia approximately 1850 as a garden plant, and in 1981 a survey in Victoria found 72,000 ha of scattered plants and an additional 6,0000 ha of moderate to densely infested area. Also introduced to Tasmania and now "grows abundantly on parts of the North Coast" as well as occurring in several other regions. (3)
Sources of information:
(1) Vanderhoff, R. 2017. Personal communication.
(2) CRC (2003)
(3) Parsons, W.T., & Cuthbertson E.G. (2001)
|
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
|
B
Observational
|
Describe trend:
Information from local expert R. Vanderhoff: The first US detection was at Palomar College (San Diego County) in 1990, a population that may or may not still be extant. The species is not widespread in the state and is concentrated near the coastline in Orange County.
In terms of management activities, "No management activity has been planned or executed at the two Orange County colonies. The plants are spread across a multitude of private property owners as well as city and probably state property. " (1)
THIS INFORMATION ABOUT A PARTICULAR POPULATION BELONGS IN 2.2. EB
I SHIFTED MUCH OF THAT INFO, INCLUDING THE NO MANAGEMENT INFO TO 2.2 (LOCAL MANAGEMENT INFO ALSO LEFT INCLUDED HERE BECAUSE THE GUIDANCE INDICATES MANAGEMENT EFFORTS ARE RELEVANT TO THIS QUESTION).
Sources of information:
(1) R Vanderhoff, personal communication (1/9/17)
|
Question 2.4 Innate reproductive potential?
Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.
|
A
Reviewed Scientific Publication
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Describe key reproductive characteristics:
This species is an aster, the subspecies evaluated here is capable of up to 8 seeds per inflorescence (head). Based on the number of heads produced per year, estimated at up to 50,000 seeds per plant per year. Noted that bees and other visitors "may not be essential for pollination" (implying that selfing is possible). 50% germination rate, seeds set into the seedbank persist and are viable for at least 3 years, depending on depth of burial. Vegetative reproduction is possible via layering. Fragmentation and dispersal does not seem likely based on the habitat. Adventitious budding allows resprouting after herbivory or fire (light). (1)
Sources of information:
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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.
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B
Other Published Material
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Identify dispersal mechanisms:
The pathway of introduction of C. monilifera ssp. monilifera in California is unknown, but a closely related/non-invasive species, C. incana, is marginally in the landscape trade currently. My suspicion is that horticulture would be the likely point if introduction, especially since the first CA detection (now extirpated?) was adjacent to the horticulture department at a college in San Diego County (1).
There has been some noted dispersal via dumping of garden refuse in Australia; however it is now illegal to sell there, limiting this mechanism of spread. It was also used for "sandbinding" (sand stabilization) in many areas, promoting spread (now also prohibited). Infestations are noted to be centered around population centers in Tasmania.
Contaminated gravel has been implicated in regional spread in some areas, and there is some mention of dispersal via machinery (3); however, the hard-seeded species does not seem specifically amenable to dispersal this way over any other species. The key would be movement of contaminated soils, not necessarily the use of machines.
Sources of information:
(1) R Vanderhoff, personal communication (1/9/17)
(2) Weiss et al. (2008)
(3) Brougham et al. (2006)
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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.
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A
Reviewed Scientific Publication
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Identify dispersal mechanisms:
Animals are implicated in "readily" spreading the fleshy fruit in Australia long distances, including sheep, cattle, non-native foxes, birds (emu), and several large marsupials. (1,2)
Sources of information:
(1) Brougham et al. (2006)
(2) Parsons, W.T. & Cuthbertson, E.G.. (2001)
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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.
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A
Reviewed Scientific Publication
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Identify other regions:
Noted in Australia as growing in a wide range of climatic conditions, in sandy/medium-textured soils, and being tolerant of saline conditions and salt spray. Noted as invading "malee scrub", open eucalypt-dominated forests, and coastal fringe. These may be analagous to coastal sage scrub, oak or other open woodlands, and coastal bluffs. (1)
Noted as occurring with both a canopy, and in the open, and invading a "range of communities" in Australia. It is "intolerant of water-logged soils however it can grow along watercourses and in estuarine areas." "Boneseed It is capable of growing in coastal ecosystems such as dune forests and woodlands, dune scrub, estuarine areas, heathlands, headlands, grasslands and dry sclerophyll forests. It also occurs in a range of communities further inland, including mallee shrubland and open eucalypt woodland." These also map similarly to coastal bluffs, coastal sage scrub, estuarine areas, grasslands, and perhaps interior oak woodlands and inland sage scrub. (2)
Sources of information:
(1) CRC (2003)
(2) Weiss (2008)
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| Section 3: Distribution |
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.
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C
Other Published Material
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Specimens in the Consortium of CA Herbaria are noted to be from coastal sage scrub and coastal bluff communities. The first specimens were collected in 1990 in San Diego (Palomar) and Orange County (Irvine) near colleges. The Palomar specimen was noted to be located on a hillside northeast of Palomar College.(1) The first reports of C. monilifera ssp. monilifera naturalizing further away from plantings were in 2013 in Orange County (2). Although in Australia this species occurs on dunes (3), no specimens were noted as being present on dunes.
Sources of information:
(1) Consortium of California Herbaria (Accessed 1/8/17)
(2) Calflora database (Accessed 1/8/17)
(3) Brougham et al. 2006
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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.
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D
Other Published Material
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Describe distribution:
Plants are distributed on coastal bluffs in Aliso Canyon, including the periphery of dune edges, where heavy foot traffic may be keeping this and other plants from establishing on the dunes. (1)
San Diego herbaria specimens note coastal sage scrub habitat. (2)
This plant is found in discrete, not ubiquitous populations, with <5% frequency in all of coastal bluff and coastal sage scrub habitats. (1)
Sources of information:
(1) R Vanderhoff, personal communication (1/9/17)
(2) Calflora (accessed 1/9/17)
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| 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 |
Yes |
| Fragments easily and fragments can become established elsewhere |
No |
| Resprouts readily when cut, grazed, or burned |
Yes |
| Total points: |
9
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| 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).
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Related traits:
Vegetative reproduction noted as via layering. Information from Weiss (2008).
Worksheet B - Arizona Ecological Types is not included here
(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)
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| Marine Systems | marine systems | |
| Freshwater and Estuarine | lakes, ponds, reservoirs | |
| Aquatic Systems | rivers, streams, canals | |
| estuaries | |
| Dunes | coastal | |
| desert | |
| interior | |
| Scrub and Chaparral | coastal bluff scrub | D, < 5% |
| coastal scrub | D, < 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 Communities | coastal prairie | |
| valley and foothill grassland | |
| Great Basin grassland | |
| vernal pool | |
| meadow and seep | |
| alkali playa | |
| pebble plain | |
| Bog and Marsh | bog and fen | |
| marsh and swamp | |
| Riparian and Bottomland habitat | riparian forest | |
| riparian woodland | |
| riparian scrub (incl.desert washes) | |
| Woodland | cismontane woodland | |
| piñon and juniper woodland | |
| Sonoran thorn woodland | |
| Forest | broadleaved upland forest | |
| North Coast coniferous forest | |
| closed cone coniferous forest | |
| lower montane coniferous forest | |
| upper montane coniferous forest | |
| subalpine coniferous forest | |
| Alpine Habitats | alpine boulder and rock field | |
| alpine dwarf scrub | |
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Amplitude (breadth): |
C |
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Distribution (highest score): |
D |
Infested Jepson Regions
Click here for a map of Jepson regions
