Plant Assessment Form

More Cortaderia selloana resources

Cortaderia selloana

Common Names: pampasgrass; white pampasgrass

Evaluated on: 5/14/04

List committee review date: 08/07/2005

Re-evaluation date:

Evaluator(s)

Alison E Stanton
BMP Ecosciences
2163 Cornelian Drive South Lake Tahoe, CA 96150
530 573 1177
alisonestanton@sbcglobal.net

List committee members

Alison E Stanton
Joe DiTomaso
Cynthia Roye
Joanna Clines
Doug Johnson

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? High

Alert Status? No Alert

Documentation? 3 out of 5

Score

Documentation

1.1

?Impact on abiotic ecosystem processes

B. Moderate

Reviewed Scientific Publication

Impact?
Four-part score BAAD Total Score
A

1.2

?Impact on plant community

A. Severe

Reviewed Scientific Publication

1.3

?Impact on higher trophic levels

A. Severe

Other Published Material

1.4

?Impact on genetic integrity

D. None

Reviewed Scientific Publication

2.1

?Role of anthropogenic and natural disturbance in establishment

B. Moderate

Observational

Invasiveness?
Total Points
17 Total Score A

2.2

?Local rate of spread with no management

A. Increases rapidly

Observational

2.3

?Recent trend in total area infested within state

B. Increasing less rapidly

Observational

2.4

?Innate reproductive potential
(see Worksheet A)

A. High

Reviewed Scientific Publication

2.5

?Potential for human-caused dispersal

A. High

Observational

2.6

? Potential for natural long-distance dispersal

A. Frequent

Reviewed Scientific Publication

2.7

?Other regions invaded

C. Already invaded

Reviewed Scientific Publication

3.1

?Ecological amplitude/Range
(see Worksheet C)

A. Widespread

Reviewed Scientific Publication

Distribution?
Total Score B

3.2

?Distribution/Peak frequency
(see Worksheet C)

C. 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.	B Reviewed Scientific Publication
Identify ecosystem processes impacted: fire intensity, fire frequency These large plants produce significant amounts of biomass that is extremely flammable, increasing both the frequency and intensity of fire. The large size also significantly reduces light availability, especailly in mono-specific stands. Sources of information: 1.Gadcil, R.L. A.L. Knowles, and J.A. Zabkiewicz. 1984. Pampas-A new forest weed problem. Proc. 37th New Zealand Weed and Pest Control Conference. p187-190. 2.Gadcil, R.L., A.M. Sandberg, P.J. Allen, and S. S. Gallagher. 1990. Partial suppression of pamaps grass by other species at the seedling stage. Proceedings of an Internation al Conference, Rotorua, New Zealand, July 1989. Ministry of Forestry FRI Bulletin 155. 3.Gadcil, R.L., P.G. Barton, P.J. Allen, and A.M. Sandberg. 1990. Growth of pampas grass (Cortaderia spp.) in New Zealand Pinus radiata forests. New Zealand Journal of Forestry Science 20(2):176-183. 4.Harradine, A.R. 1991. The impact of pampas grass as weeds in southern Australia. Plant Protection Quarterly 6:111-115.
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.	A Reviewed Scientific Publication
Identify type of impact or alteration: Alters plant community conposition and structure. Develops mono-specific stands with >75% cover, eliminates lower layers, displaces native species, and creates a new layer in maritime chaparral and other scrub ecossystems. San Diego plants? Sources of information: 1. Lambrinos, J. G. 2000. The impact of the invasive alien grass Cortaderia jubata (Lemoine) Stapf on an endangered mediterranean-type shrubland in California. Diversity and Distributions. 6:217-231 2. Rawling, J.L. 1988. The ecology and distribution of pampas grass (Cortaderia selloana) in Sydney bushland. Masters thesis. Macquerie University, Australia.
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.	A Other Published Material
Identify type of impact or alteration: Total alteration of native plant communities decreases forage and nesting sites for native animals, although rats, some snakes, and rabbits have been observed in dense infestations. Rare plants and animals in San Diego? Sources of information: USFWS
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
No native congeners Sources of information: 1. Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA
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.	A Observational
Describe role of disturbance: Often found in distrubed areas, including roadsides, logged forests, and railroad tracks. Also colonize narturally occuring landslides Germination requires light, but seedlings occasionally establish in undisturbed areas. Sources of information: 1. Drewitz, J.J., and J. M. DiTomaso. 2000. Seed biology and control of jubatagrass. Proceedings of the California Exotic Pest Plant Council Symposium 2000. 6:32 2. Tschohl, A. 2000. Jubatagrass vs. pampasgrass: a growth analysis and comparison of invasive potential. Proceedings of the California Exotic Pest Plant Council Symposium 2000. 6:32-33 3.Costas-Lippmann, M. 1976. Ecology and reproductive biology of the genus Cortaderia in California. Doctoral dissertation, University of California, Berkeley 4.Stanton, A.E. 2000. Cortaderia in California:seedling ecology and management. Masters thesis. University of California, Davis.
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	A Observational
Describe rate of spread: Increases rapidly after initial colonization Prolific seed production and light, wind-dispersed seeds facilitate rapid expansion. Sources of information: 1.Conner, H.E. 1965. Breeding systems in New Zealand grasses V. Naturalized species of Cortaderia. New Zealand Journal of Botany 3:17-23 2.Costas-Lippmann, M. 1976. Ecology and reproductive biology of the genus Cortaderia in California. Doctoral dissertation, University of California, Berkeley
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: Much of the coastal habitat appears to be saturated with infestations, but the total acreage in the state is probably still increasing pampasgrass may be increasing in the Central Valley. It is most prevalent South of Santa Barbara, but is still widely available in the nursery trade. Sources of information: 1. Lambrinos, J. G. 2000. The impact of the invasive alien grass Cortaderia jubata (Lemoine) Stapf on an endangered mediterranean-type shrubland in California. Diversity and Distributions. 6:217-231 2.Stanton, A.E. 2000. Cortaderia in California:seedling ecology and management. Masters thesis. University of California, Davis.
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
Describe key reproductive characteristics: Produces prolific seed, more than 100,00 seed on a single plume, although only about 30% are viable. Sources of information: 1. Drewitz, J.J., and J. M. DiTomaso. 2000. Seed biology and control of jubatagrass. Proceedings of the California Exotic Pest Plant Council Symposium 2000. 6:32 2. Tschohl, A. 2000. Jubatagrass vs. pampasgrass: a growth analysis and comparison of invasive potential. Proceedings of the California Exotic Pest Plant Council Symposium 2000. 6:32-33 3.Costas-Lippmann, M. 1976. Ecology and reproductive biology of the genus Cortaderia in California. Doctoral dissertation, University of California, Berkeley 4.Stanton, A.E. 2000. Cortaderia in California:seedling ecology and management. Masters thesis. University of California, Davis.
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.	A Observational
Identify dispersal mechanisms: Widely sold in the nursery trade. Humans cut and carry around the plumes including placing plumes on cars and trucks. Sources of information: 1.Stanton, A.E. 2000. Cortaderia in California:seedling ecology and management. Masters thesis. University of California, Davis.
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.	A Reviewed Scientific Publication
Identify dispersal mechanisms: Seed can blow up to 20 miles in the wind. Seed stick to animal fur and get stuck on other vegetation Sources of information: 1.Costas-Lippmann, M. 1976. Ecology and reproductive biology of the genus Cortaderia in California. Doctoral dissertation, University of California, Berkeley 2.Harradine, A.R. 1991. The impact of pampas grass as weeds in southern Australia. Plant Protection Quarterly 6:111-115.
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.	C Reviewed Scientific Publication
Identify other regions: Australia, New Zealand,South Africa Sources of information: 1.Harradine, A.R. 1991. The impact of pampas grass as weeds in southern Australia. Plant Protection Quarterly 6:111-115. 2. Rawling, J.L. 1988. The ecology and distribution of pampas grass (Cortaderia selloana) in Sydney bushland. Masters thesis. Macquerie University, Australia.
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.	A Reviewed Scientific Publication
Distribution is primarily coastal, south of Santa Barbara. Not found on serpentine soils. Co-occurs with jubatagrass in large urban centers, including the North Coast. Escaping in interior regions, esspecially in riparian zones. Introduced to CA in 1872. Tolerates frost, utilizes higher light intensities, survives at higher temperatures. Sources of information: Costas-Lippmann, Stanton
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.	C Observational
Describe distribution: Sources of information: Stanton, DiTomaso

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less	Yes
Dense infestations produce >1,000 viable seed per square meter	Yes
Populations of this species produce seeds every year.	Yes
Seed production sustained over 3 or more months within a population annually	Yes
Seeds remain viable in soil for three or more years	No
Viable seed produced with both self-pollination and cross-pollination	No
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes	No
Fragments easily and fragments can become established elsewhere	No
Resprouts readily when cut, grazed, or burned	Yes
Total points:	6
Total unknowns:	0
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).

Related traits:

Worksheet B - Arizona Ecological Types is not included here

Worksheet C - California Ecological Types

(sensu Holland 1986)

Major Ecological Types	Minor Ecological Types	Code? 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	C, 5% - 20%
	coastal scrub	C, 5% - 20%
	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	C, 5% - 20%
	valley and foothill grassland
	Great Basin grassland
	vernal pool
	meadow and seep	D, < 5%
	alkali playa
	pebble plain
Bog and Marsh	bog and fen
Bog and Marsh	marsh and swamp
Riparian and Bottomland habitat	riparian forest
	riparian woodland	D, < 5%
	riparian scrub (incl.desert washes)
Woodland	cismontane woodland
	piñon and juniper woodland
	Sonoran thorn woodland
Forest	broadleaved upland forest
	North Coast coniferous forest	D, < 5%
	closed cone coniferous forest	D, < 5%
	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):	A
	Distribution (highest score):	C

Infested Jepson Regions

Click here for a map of Jepson regions

Cascade Range
Central West
Great Valley
Northwest
Sierra Nevada
Southwest
Modoc Plateau
Sierra Nevada East
Desert Province
Mojave Desert
Sonoran Desert

California Invasive Plant Council

Protecting California’s environment and economy from invasive plants

Plant Assessment Form

More Cortaderia selloana resources

Cortaderia selloana

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