Plant Assessment Form

More Schismus arabicus resources

Schismus arabicus

Common Names: Mediterranean grass; Arabian schismus

Evaluated on: 9/4/03

List committee review date: 04/09/2003

Re-evaluation date:

Evaluator(s)

Matt Brooks/Research Botanist
U.S. Geological Surveye
160 N.Stephanie St., Henderson, NV 89074
702-564-4615
matt_brooks@usgs.gov

List committee members

Matt Brooks
Doug Johnson
Joe DiTomaso
Peter Warner

General Comments

5/26/17 Note by Ramona Robison This PAF was originally written for Schismus arabicus and Schismus barbatus. It has now been split into two species and the information copied into each. The Schismus spp. are considered together in Invasive Plants of Califonia’s Wildlands (Bossard et al. 2000). "Schismus barbatus and S. arabicus are so genetically and morphologically similar (Faruqui and Quarish 1979, Faruqui 1981, Bor 1968), with similar geographic ranges and habitats in California (Hickman 1993), that they are treated together here."

Table 2. Criteria, Section, and Overall Scores

Overall Score? Limited

Alert Status? No Alert

Documentation? 2.5 out of 5

Score

Documentation

1.1

?Impact on abiotic ecosystem processes

B. Moderate

Reviewed Scientific Publication

Impact?
Four-part score BBCU Total Score
B

1.2

?Impact on plant community

B. Moderate

Reviewed Scientific Publication

1.3

?Impact on higher trophic levels

C. Minor

Other Published Material

1.4

?Impact on genetic integrity

U. Unknown

2.1

?Role of anthropogenic and natural disturbance in establishment

B. Moderate

Reviewed Scientific Publication

Invasiveness?
Total Points
10 Total Score C

2.2

?Local rate of spread with no management

A. Increases rapidly

Other Published Material

2.3

?Recent trend in total area infested within state

C. Stable

Observational

2.4

?Innate reproductive potential
(see Worksheet A)

B. Moderate

Observational

2.5

?Potential for human-caused dispersal

U. Unknown

2.6

? Potential for natural long-distance dispersal

C. Rare

Observational

2.7

?Other regions invaded

C. Already invaded

Observational

3.1

?Ecological amplitude/Range
(see Worksheet C)

A. Widespread

Observational

Distribution?
Total Score A

3.2

?Distribution/Peak frequency
(see Worksheet C)

A. High

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: B: Possibly fire frequency in arid and semi-arid shrublands Produces high amounts of continuous fine fuels were they did not previously exist, facilitating the spread of fire where fire is historically infrequent. Sources of information: Brooks, M.L. 1999a. Alien annual grasses and fire in the Mojave Desert. Madro_o 46:13-19, enter text here
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: B: May reduce vigor, fecundity, and species diveristy of native annual plant communities. Can compete with native annual plants, reducing the biomass and species richness of seedling cohorts. Can have high % cover, but usually only after disturbances such as fire. When it arrived in the early 1900s, the similar native annual grass, Vulpia octoflora, declined in abundance. Sources of information: Brooks, M.L. 2000. Competition between alien annual grasses and native annual plants in the Mojave Desert. American Midland Naturalist 144:92-108. Brooks, M.L. 2000a. Schismus arabicus Nees. Schismus barbatus (L.) Thell. In: Bossard, C., Hoshovsky, M. and Randall, J. (Eds.). Invasive Wildland Weeds of California. Berkeley: University of California Press, pp. 287-291. Brooks, M.L. and D. Pyke. 2001. Invasive plants and fire in the deserts of North America. Pp. 1-14 In K. Galley and T. Wilson (eds.), Proceedings of the Invasive Species Workshop: The Role of Fire In the Control and Spread of Invasive Species. Fire Conference 2000: The First National Congress on Fire, Ecology, Prevention and Management. Miscellaneous Publications No. 11, Tall Timbers Research Station, Tallahassee, Florida, USA. Brooks, M.L., and T.C. Esque. 2002. Alien annual plants and wildfire in desert tortoise habitat: status, ecological effects, and management. Chelonian Conservation and Biology 4:330-340.
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 Other Published Material
Identify type of impact or alteration: C: Competes with native annual plants that are preferred forage for the desert tortoise. Seeds may be eaten by small native ants, since they are collected by then and deposited around ant mounds. Seeds are probably too small to be used by vertebrate granivores. Mature plants oberved grazed by unknown animals (not livestock since they have been observed grazed in areas closed to livestock use. Sources of information: Brooks, M.L., and T.C. Esque. 2002. Alien annual plants and wildfire in desert tortoise habitat: status, ecological effects, and management. Chelonian Conservation and Biology 4:330-340. Brooks, M.L. and D. Pyke. 2001. Invasive plants and fire in the deserts of North America. Pp. 1-14 In K. Galley and T. Wilson (eds.), Proceedings of the Invasive Species Workshop: The Role of Fire In the Control and Spread of Invasive Species. Fire Conference 2000: The First National Congress on Fire, Ecology, Prevention and Management. Miscellaneous Publications No. 11, Tall Timbers Research Station, Tallahassee, Florida, USABrooks, M.L. 2000. Competition between alien annual grasses and native annual plants in the Mojave Desert. American Midland Naturalist 144:92-108.
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.	U
U: unknown, no native congeners in California Sources of information: Hickman, J.C. (ed.). 1993. The Jepson Manual: Higher plants of California. University of California Press, Berkeley, CA. 1400 p.
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 Other Published Material
Describe role of disturbance: B: Anthropogenic disturbance facilitates dominance of this species, in biomass and cover continuity. Very high cover in areas disturbed by OHVs, fire, and previous cropping agriculture. Sources of information: Brooks, M.L. 2000. Schismus arabicus Nees. Schismus barbatus (L.) Thell. In: Bossard, C., Hoshovsky, M. and Randall, J. (Eds.). Noxious Wildland Weeds of California. Berkeley: University of California Press, pp. 287-291. Brooks, M.L. 2000. Competition between alien annual grasses and native annual plants in the Mojave Desert. American Midland Naturalist 144:92-108. Brooks, M.L., and T.C. Esque. 2002. Alien annual plants and wildfire in desert tortoise habitat: status, ecological effects, and management. Chelonian Conservation and Biology 4:330-340. Brooks, M.L. and D. Pyke. 2001. The role of firein the deserts of North America. Pp. 1-14 In K. Galley and T. Wilson (eds.), Proceedings of the Invasive Species Workshop: The Role of Fire In the Control and Spread of Invasive Species. Fire Conference 2000: The First National Congress on Fire, Ecology, Prevention and Management. Miscellaneous Publications No. 11, Tall Timbers Research Station, Tallahassee, Florida, USA. Brooks, 1999. Biological Invasions
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 Other Published Material
Describe rate of spread: A: probably can spread rapidly. Years of high rainfall produce huge increases in cover and biomass dominance. Can disperse locally by "tumbleweed" action. Sources of information: Brooks, M.L. 2000a. Schismus arabicus Nees. Schismus barbatus (L.) Thell. In: Bossard, C., Hoshovsky, M. and Randall, J. (Eds.). Noxious Wildland Weeds of California. Berkeley: University of California Press, pp. 287-291. Brooks, M.L., and T.C. Esque. 2002. Alien annual plants and wildfire in desert tortoise habitat: status, ecological effects, and management. Chelonian Conservation and Biology 4:330-340.
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	C Observational
Describe trend: C: May still be spreading since it first appeared in the 1900s, however has likely already naturalized in most habitats where it is likely to end up Sources of information: Brooks, M.L. 2000a. Schismus arabicus Nees. Schismus barbatus (L.) Thell. In: Bossard, C., Hoshovsky, M. and Randall, J. (Eds.). Noxious Wildland Weeds of California. Berkeley: University of California Press, pp. 287-291. Brooks, M.L., and T.C. Esque. 2002. Alien annual plants and wildfire in desert tortoise habitat: status, ecological effects, and management. Chelonian Conservation and Biology 4:330-340.
Question 2.4 Innate reproductive potential? Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.	B Observational
Describe key reproductive characteristics: B: reproductive maturity in <2 years, high seed production Sources of information: Matt Brooks personal observation
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.	U
Identify dispersal mechanisms: U: may pass through the guts of livestock Sources of information: no information
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 Observational
Identify dispersal mechanisms: C: Probably low, moderate-distance dispersal by saltation/tubleweed action Sources of information: Matt Brooks personal observation
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 Observational
Identify other regions: C: has invaded similar arid/semi-arid systems in Autralia, W Europe, South America Has invaded similar habitats in NA as elsewhere Sources of information: Bor, N.L. 1968. Schismus in Townsend, Guest, and Al-Rawi. Flora of Iraq. Volume 9. Ministry of Agriculture of Republic of Iraq, Baghdad, Iraq.
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 Observational
A: Present in dunes, scrub, grasslands, and woodlands Sources of information: Matt Brooks pers. obs.
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.	A Observational
Describe distribution: A: widespread in most low elevation desert habitats, and many sage scrub habitats Sources of information: Matt Brooks pers. obs

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	Unknown
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes	No
Fragments easily and fragments can become established elsewhere	No
Resprouts readily when cut, grazed, or burned	No
Total points:	4
Total unknowns:	2
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:

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	D, < 5%
	interior
Scrub and Chaparral	coastal bluff scrub
	coastal scrub	B, 20% - 50%
	Sonoran desert scrub	A, > 50%
	Mojavean desert scrub (incl. Joshua tree woodland)	A, > 50%
	Great Basin scrub	D, < 5%
	chenopod scrub	A, > 50%
	montane dwarf scrub
	Upper Sonoran subshrub scrub	B, 20% - 50%
	chaparral
Grasslands, Vernal Pools, Meadows, and other Herb Communities	coastal prairie
	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
	riparian scrub (incl.desert washes)
Woodland	cismontane woodland
	piñon and juniper woodland	D, < 5%
	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):	A
	Distribution (highest score):	A

Infested Jepson Regions

Click here for a map of Jepson regions

CA Floristic Province
Central West
Great Valley
Sierra Nevada
Southwest
Great Basin Province
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 Schismus arabicus resources

Schismus arabicus

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