Plant Assessment Form

More Carrichtera annua resources

Carrichtera annua

Synonyms: Vella annua

Common Names: Ward's weed

Evaluated on: 21-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.sweet@ucr.edu

List committee members

Jutta Burger
Naomi Fraga
Denise Knapp
Chris McDonald
Ron Vanderhoff
John Knapp
Elizabeth Brusati

General Comments

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)." This is the case with Carrichtera annua in California since it was first documented as occurring in natural areas here in 2007 and has not yet spread widely, but is considered invasive in Australia.

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate

Alert Status? Alert

Documentation? 3.5 out of 5

Score

Documentation

1.1

?Impact on abiotic ecosystem processes

C. Minor

Other Published Material

Impact?
Four-part score CBCD Total Score
B

1.2

?Impact on plant community

B. Moderate

Other Published Material

1.3

?Impact on higher trophic levels

C. Minor

Reviewed Scientific Publication

1.4

?Impact on genetic integrity

D. None

Reviewed Scientific Publication

2.1

?Role of anthropogenic and natural disturbance in establishment

B. Moderate

Reviewed Scientific Publication

Invasiveness?
Total Points
13 Total Score B

2.2

?Local rate of spread with no management

B. Increases less rapidly

Reviewed Scientific Publication

2.3

?Recent trend in total area infested within state

B. Increasing less rapidly

Other Published Material

2.4

?Innate reproductive potential
(see Worksheet A)

B. Moderate

Reviewed Scientific Publication

2.5

?Potential for human-caused dispersal

B. Moderate

Reviewed Scientific Publication

2.6

? Potential for natural long-distance dispersal

C. Rare

Reviewed Scientific Publication

2.7

?Other regions invaded

B. Invades 1 or 2 ecological types

Reviewed Scientific Publication

3.1

?Ecological amplitude/Range
(see Worksheet C)

C. Limited

Other Published Material

Distribution?
Total Score C

3.2

?Distribution/Peak frequency
(see Worksheet C)

D. Very low

Observational

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".

Section 1: Impact
Question 1.1 Impact on abiotic ecosystem processes? 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 Other Published Material
Identify ecosystem processes impacted: Soil erosion- Replacement of native stands in dense patches, however, it is an annual plant, and so may leave bare patches that are exposed to soil erosion (Cook 2003). Moderate probability of large scale soil movement. (1) Fire regime change low- Noted to persist as dry biomass following senescence, however, this was judged to be of minor concern. (2) Sources of information: (1) Victorian Weed Risk Assessment (WRA) (2) Cooke, Ash, & Groves (2003)
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 Other Published Material
Identify type of impact or alteration: Competition with native plants: C. annua forms dense stands, and displaces native plants and other weed species. It can comprise up to an estimated 95% of total herbaceous biomass (1). Direct replacement of biomass by invader (Victoria, Australia weed risk assessment). (2) Harris and Facelli (2003) did not find impacts on native species abundance in experimentally-manipulated densities of C. annua, however, this finding may have been due to the densities used in the experiment (too low) or may have been community-specific, where the native species chosen were segregated in life history/resource capture (native arid chenopod shrublands, Australia). (3) In the US, in San Diego County, it was assessed to be a serious threat on specific soils "that hold still relatively common sensitive forbs like Pentachaeta, Harpagonella, Microseris, and Convolvulus, not to mention Acanthomintha and other clay obligates."(4) Several other species in the Brassicaceae do not have mycorrhyzal associates and also leach compounds which tend to inhibit growth of mycorryzal hyphae, thereby effectively sterilizing a soil of fungal symbionts. It is possible that this species does the same (5) (6). Sources of information: (1) Cooke, Ash, & Groves (2003) (2) Victorian Weed Risk Assessment (WRA) (3) Harris & Facelli (2003) (4) McConnell, personal communication (2017) (5) Wixted and McGraw 2010 (6) Bell and Muller 1973
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: Unpalatable to livestock and therefore significantly reduces productivity of grazing areas (1,2). Prolific seeds that are dropped into the soil are fed upon by ants, potentially increasing locally available food for them (Cooke et al. 2013), however, there is no documented change or higher-level impact from this. (3) Sources of information: (1) Victorian Weed Risk Assessment (WRA) (2) Cooke, Ash, & Groves (2003) (3) Cooke, Ash, & Groves (2013)
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 Reviewed Scientific Publication
C. annua is in the Brassicaceae (mustard) family. There are no other Carrichtera species noted to be in California. (1) This species is most closely related to genera in the monophyletic group, Vellinae, containing Vella, Carrichtera, and Orychophragmus, and of this group, this is the only species in California. (2) While there are many other mustard species, native, non-native, and crop plants, present in California, it is unknown if C. annua can successfully cross with species in other phylogenenetic groups within Brassicaceae, but may be unlikely. Sources of information: (1) Calflora (accessed 12/30/16) (2) Bailey et al. (2006)
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: C. annua germination may be reduced by litter from other species (e.g. Casuarina trees), and less plants were found here than in open areas, however, germination may still occur under moderate canopy (1). According to Cooke and others (2003), the species is known to invade disturbed and over-grazed sites, and thus is increased by disturbance. However, this evidence and the Victorian weed risk assessment indicate that this plant does not seem to require disturbance to invade. (2,3) Sources of information: (1) Barritt & Facelli (2001) (2) Cooke, Ash, & Groves (2003) (3) Victorian Weed Risk Assessment (WRA)
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: In Australia, the plant was likely introduced to a single site, showed a lag phase of 30 years (possibly due to edaphic factors), and then has rapidly spread in that region (1). These authors believe that the specIes has reached climatic limits in just under a century due to rapid spread and some long-distance dispersal by humans (vehicle and stock movements, railways, noted in Cooke et al. 2003) (2). Local spread of its prolific seed output may be facilitated by ant species, while long-distance dispersal could be via vertebrate mammals (2). No source notes specific rate of spread, making this difficult to answer with certainty, however, the rate of spread within Australia, identified vectors, as well as local dominance indicate that it may increase rapidly. In California, noted from monitoring a mapped population in the La Costa Carlsbad (San Diego County) area that it has infested a rather large area in a short amount of time. (3) Sources of information: (1) Cooke, Groves, & Ash (2011) (2) Cooke, Ash, & Groves (2003) (3) Giessow, J. (pers. comm. 1/1/17)
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 Other Published Material
Describe trend: This species was first noted in Monterey in 1979, and not noted in San Diego County much prior to 2007 (1). There are currently two sites in southern CA: Camp Pendleton MCB and a preserve in Carlsbad (two populations, Rancho La Costa HCA), both of which are under treatment. Since the known locations are being treated the question is scored as "B: Increasing less rapidly." (2,3) Sources of information: (1) Vinje (2008) (2) Giessow, J. (pers. comm. 1/1/17) (3) San Diego MMP Plant Assessment Form 2011
Question 2.4 Innate reproductive potential? Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.	B Reviewed Scientific Publication
Describe key reproductive characteristics: Noted to have both a soil seedbank and an aerial seedbank on the standing dead matter that is less susceptible to invertebrate predation, but more susceptible to fire and other above-ground disturbance . Longevity in the soil is uknown but thought to be short. Local persistence is therefore explained by the dual banking strategy (1,2). Sources of information: (1) Meissner & Facelli (1999) (2) Cooke, Ash, & Groves (2003)
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.	B Reviewed Scientific Publication
Identify dispersal mechanisms: They may be dispersed longer distances by vehicles, on larger animals and clothing, and in contaminated agricultural produce (1). As well accidental, infrequent long-distance dispersal via vehicles and railways was noted noted in Cooke (2). In California, managers of the population in Carlsbad believe seed was introduced via erosion control devices (silt fencing) when the developer on the adjacent parcel was creating house pads (3). Sources of information: (1) Weeds of Australia: Biosecurity Queensland Edition (accessed 12/30/16) (2) Cooke, Ash, & Groves (2003) (3) Vinje 2011
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.	C Reviewed Scientific Publication
Identify dispersal mechanisms: Dispersal mechanisms are thought to be primarily local- ants, gravity and water. The plant has no adaptation for wind dispersal. The species has some limited water dispersal adaptation (1) due to a mucilaginous seed coat, however, this is not a long-distance dispersal mechanism. Possible long-distance dispersal via emu, or other vertebrate species in Australia has been suggested, but not documented (2). Sources of information: (1) Gutterman, Yitzchak & Shem-Tov (1997) (2) Cooke, Ash, & Groves (2003)
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.	B Reviewed Scientific Publication
Identify other regions: Native to Southern Europe, Mediterranean Islands, and Northern Africa.(1) Serious weed of semi-arid rangelands in Australia, where it is a significant environmental weed in Victoria, South Australia and Western Australia. (3) Noted as present in types in Australia: native arid chenopod shrublands Australia specifically (4,5,6), as well as "rangelands, grasslands, open woodlands, pastures, disturbed sites, and waste areas in semi-arid regions."(3) Listed in Victoria risk assessment as being present in: Semi-arid woodland, Shrubby Woodland. New types that may be invaded by this species in California based on this information: chenopod scrub, and open woodland. (7) Sources of information: (1) GBIF (Accessed 12/26/16) (2) Cooke et al. 2011 (3) Weeds of Australia Biosecurity Queensland Edition (accessed 12/30/16)) (4) Harris & Facelli (2003) (5) Meissner & Facelli (1999) (6) Facelli & Chesson (2008) (7) Victorian Weed Risk Assessment (WRA)
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.	C Other Published Material
This species was first noted in Monterey in 1979, and was not noted in San Diego County much prior to 2007 (1). Two geolocated observations of C. annua are listed on the Consortium of California Herbaria website, out of 12 total observations. The earliest specimens are from 2007, and the latest 2016, all from San Diego County (2). The Plant Assessment Form from the San Diego MMP lists non-native grassland and Diegan Coastal Sage Scrub. Chaparral has also been noted as a community type it occurs in. (3) In Carlsbad, this plant was located on a southern-facing slope growing among open Diegan coastal sage scrub dominated by California sage (Artemisia californica). Associates included coast sunflower (Encelia californica), buckwheat (Eriogonum fasciculatum), lemonade berry (Rhus integrifolia), and tocalote (Centaurea melitensis). C. annua was growing on open clay lenses in the coastal sage scrub and underneath the shrubs. Although vernal pool affiliates were noted on consortium specimens, observational evidence suggests: "This plant thrives in open areas, including scrub understory. It does not like long term inundation and competes poorly with dense herbaceous cover." (4) Sources of information: (1) Vinje 2008 (2) Consortium of California Herbaria (accessed 12/30/16) (3) San Diego MMP Plant Assessment Form 2011 (4) J. Giessow, personal communication (1/4/17)
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.	D Observational
Describe distribution: This species has only been documented in San Diego County, near the coastline, in the La Costa Carlsbad area and at Camp Pendleton (1). It is present but not >5% in coastal sage scrub and bluff, and chaparral (1,2). Sources of information: (1) Consortium of California Herbaria (accessed 12/30/16) (2) J. Giessow, personal communication (1/4/17)

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less	Yes
Dense infestations produce >1,000 viable seed per square meter	Yes
Populations of this species produce seeds every year.	Yes
Seed production sustained over 3 or more months within a population annually	No
Seeds remain viable in soil for three or more years	Unknown
Viable seed produced with both self-pollination and cross-pollination	Yes
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes	No
Fragments easily and fragments can become established elsewhere	No
Resprouts readily when cut, grazed, or burned	No
Total points:	5
Total unknowns:	1
Total score:	B? 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).

Related traits:

Noted to have both a soil seedbank and an aerial seedbank on the standing dead matter.

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 Systems	marine systems
Freshwater and Estuarine	lakes, ponds, reservoirs
Aquatic Systems	rivers, streams, canals
Aquatic Systems	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	D, < 5%
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
Bog and Marsh	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 Habitats	alpine dwarf scrub
	Amplitude (breadth):	C
	Distribution (highest score):	D

Infested Jepson Regions

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Southwest

California Invasive Plant Council

Protecting California’s environment and economy from invasive plants

Plant Assessment Form

More Carrichtera annua resources

Carrichtera annua

Evaluator(s)

List committee members

General Comments

Table 2. Criteria, Section, and Overall Scores

Table 3. Documentation

Worksheet A - Innate reproductive potential

Related traits:

Worksheet C - California Ecological Types

Infested Jepson Regions