Plant Assessment Form

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 commitee 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 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? 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?
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? 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? 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?
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? 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? 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? 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? 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? 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? 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? A Observational

A: Present in dunes, scrub, grasslands, and woodlands


Sources of information:

Matt Brooks pers. obs.


Question 3.2 Distribution/Peak frequency? 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?

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?
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
estuaries
Dunescoastal
desertD, < 5%
interior
Scrub and Chaparralcoastal bluff scrub
coastal scrubB, 20% - 50%
Sonoran desert scrubA, > 50%
Mojavean desert scrub (incl. Joshua tree woodland)A, > 50%
Great Basin scrubD, < 5%
chenopod scrubA, > 50%
montane dwarf scrub
Upper Sonoran subshrub scrubB, 20% - 50%
chaparral
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairie
valley and foothill grassland
Great Basin grassland
vernal pool
meadow and seepD, < 5%
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forest
riparian woodland
riparian scrub (incl.desert washes)
Woodlandcismontane woodland
piñon and juniper woodlandD, < 5%
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forest
closed cone coniferous forest
lower montane coniferous forest
upper montane coniferous forest
subalpine coniferous forest
Alpine Habitatsalpine boulder and rock field
alpine dwarf scrub
Amplitude (breadth): A
Distribution (highest score): A

Infested Jepson Regions

Click here for a map of Jepson regions