Plant Assessment Form

Hordeum marinum

Synonyms: H. marinum ssp. gussoneanum, H. geniculatum, H. gussoneanum. H. hystrix, Critesion geniculatum, C. hystrix, C. marinum

Common Names: Mediterranean barley; seaside barley

Evaluated on: 2/8/05

List committee review date: 08/07/2005

Re-evaluation date:

Evaluator(s)

Elizabeth Brusati, project manager
California Invasive Plant Council
1442A Walnut St. #462, Berkeley, CA 94709
510-843-3902
edbrusati@cal-ipc.org
Joseph DiTomaso
University of California-Davis
Dept. Plant Sci., Mail Stop 4, Davis, CA 95616
530-754-8715
jmditomaso@ucdavis.edu

List commitee members

Joe DiTomaso
Alison Stanton
Joanna Clines
Cynthia Roye
Doug Johnson

General Comments

5/26/17 Note by Ramona Robison
This PAF was originally written for both Hordeum marinum and Hordeum murinum. It has now been split into two species and the information copied into each. Both PAFs should be updated with current scientific literature and to reflect the fact that they have different ecological tolerances.

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate
Alert Status? No Alert
Documentation? 3 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U Reviewed Scientific Publication
Impact?
Four-part score UCCD Total Score
C
1.2 ?Impact on plant community C. Minor Reviewed Scientific Publication
1.3 ?Impact on higher trophic levels C. Minor 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 Reviewed Scientific Publication
Invasiveness?
Total Points
11 Total Score B
2.2 ?Local rate of spread with no management C. Stable Observational
2.3 ?Recent trend in total area infested within state C. Stable Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
B. Moderate Reviewed Scientific Publication
2.5 ?Potential for human-caused dispersal B. Moderate Other Published Material
2.6 ? Potential for natural long-distance dispersal B. Occasional Other Published Material
2.7 ?Other regions invaded C. Already invaded Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
A. Widespread Other Published Material
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? U Reviewed Scientific Publication
Identify ecosystem processes impacted:

Like many other annual grasses, they could increase fire frequency. They typically do not get to densities high enough to do this, however.


Sources of information:

DiTomaso, observational.


Question 1.2 Impact on plant community composition,
structure, and interactions?
C Reviewed Scientific Publication
Identify type of impact or alteration:

Outcompetes perennial grasses, for example, by tolerating higher salinity and invading bare areas when perennials die. (1). But impacts in California are relatively minor (2).


Sources of information:

1. Popay, A. I. and P. Sanders 1982. "Seasonal variations in salinity of soils supporting different levels of barley grass Hordeum murinum. New Zealand Journal of Agricultural Research 25(2): 223-228.
2. Weed list committee (Joe DiTomaso, Carla Bossard, Jake Sigg, Peter Warner), 9/15/05


Question 1.3 Impact on higher trophic levels? C Other Published Material
Identify type of impact or alteration:

Livestock forage early in season. Later in season, develop flower spikelets with stiff, barbed awns that injure mouths, eyes, nasal passages, and skin of animals (1). No specific information on damage to wildlife. Probably good forage early on.


Sources of information:

DiTomaso, J. and E. Healy. Weeds of California and Other Western States.


Question 1.4 Impact on genetic integrity? D Reviewed Scientific Publication

There are five species of native Hordeum in California, along with several subspecies (1). Field and greenhouse experiments found no hybridization, nor were there any hybrids of H. murinum in contact zones with cultivated barley. There appear to be genetic barriers against hybridization (2).


Sources of information:

1. Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA
2. Savova Bianchi, D., J. Keller Senften, and F. Felber. 2002. Isozyme variation of Hordeum murinum in Switzerland and test of hybridization with cultivated barley. Weed Research 42(4): 325-333.


Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
C Observational
Describe role of disturbance:

Inhabit mostly disturbed sites (1). H. murinum was restricted by competition with other grasses to disturbed sites in New Zealand (2), whereas H. marinum ssp. gussoneanum can also invade the edges of vernal pools and relatively undisturbed grassland in California (2).


Sources of information:

1. DiTomaso, J. and E. Healy. in prep. Weeds of California and Other Western States.
2. Popay, A. I. and P. Sanders. 1982. Seasonal variations in salinity of soils supporting different levels of barley grass Hordeum murinum. New Zealand Journal of Agricultural Research 25(2): 223-228.
3. Hoopes, M. F. and L. M. Hall 2002. Edaphic factors and competition affect pattern formation and invasion in a California grassland. Ecological Applications 12(1): 24-39.


Question 2.2 Local rate of spread with no management? C Observational
Describe rate of spread:

Depends on conditions of grasslands. Under healthy conditions, the rate of spread is slow. Degraded grasslands, in contrast, can be heavily invaded. Rarely are the wild barleys the dominant vegetation in a grassland.


Sources of information:

DiTomaso, observational.


Question 2.3 Recent trend in total area infested within state? C Observational
Describe trend:

Species have been around for a long time and seem to be widely distributed, such that their continued spread is probably static.


Sources of information:

DiTomaso, observational.


Question 2.4 Innate reproductive potential? B Reviewed Scientific Publication
Describe key reproductive characteristics:

Cool season annual grasses that reproduce by seed. Seeds usually germinate after the first fall rain (1). Few seeds survive to germinate in winter and spring. Very few seeds are likely to be present after a year (2).


Sources of information:

1. DiTomaso and Healy
2. Popay, A. I. 1981. Germination of seeds of five annual species of barley grass. Journal of Applied Ecology 18(2): 547-558.


Question 2.5 Potential for human-caused dispersal? B Other Published Material
Identify dispersal mechanisms:

May be spread when spikelets attach to tires, farm equipment, shoes, or clothing (1). Can also be a contaminant of hay.


Sources of information:

1. DiTomaso and Healy in prep


Question 2.6 Potential for natural long-distance dispersal? B Other Published Material
Identify dispersal mechanisms:

Spikelets fall near parent plant and may disperse to greater distances by wind or by attaching to fur and feathers of animals (1).


Sources of information:

1. DiTomaso and Healy in prep


Question 2.7 Other regions invaded? C Other Published Material
Identify other regions:

Native to Europe. Present in Oregon, Washington, Idaho, Montana, Nevada, Utah, Arizona, Oklahoma. Mediterranean barley also in some northeastern states. Hare barley also in some eastern states (1). H. murinum common in New Zealand (2). In Arizona, H. murinum inhabits Prosopis woodland (3).


Sources of information:

1. DiTomaso and Healy in prep
2. Popay, A. I. 1981. Germination of seeds of five annual species of barley grass. Journal of Applied Ecology 18(2): 547-558
3. Stromberg, J. C., L. Gengarelly, et al. 1997. Exotic herbaceous species in Arizona's riparian ecosystems. pp. 45-57 in Brock, J. H. , Wade, M., Pysek, P., Green, D. [Editors]. Plant invasions: Studies from North America and Europe. Backhuys Publishers, Leiden, The Netherlands..


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? A Other Published Material

Probably introduced to California with Spanish colonists and spread with cattle grazing in the 1800's (1). Both species occur throughout California, except mountains. Mediterranean barley to 1500m; hare barley to 1000m Both species inhabit roadsides, fields, annual grassland, oak savannah, open hillsides, agronomic crops, waste places and other disturbed sites. Mediterranean barley grows in moist or dry places. Hare barley grows in moist sites (1). H. marinum ssp. gussoneanum can also invade the edges of vernal pools and relatively undisturbed sites (2). 1. DiTomaso and Healy in prep
2. Hoopes and Hall 2002
Alison Stanton, BMP Ecosciences, and Joanna Clines, US Forest Service, pers. obs.


Sources of information:

Question 3.2 Distribution/Peak frequency? A Observational
Describe distribution:

Very frequently encountered in Valley and foothill grasslands.


Sources of information:

DiTomaso, observational.


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 No
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: 1
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
desert
interior
Scrub and Chaparralcoastal bluff scrubC, 5% - 20%
coastal scrubC, 5% - 20%
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrubD, < 5%
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparralC, 5% - 20%
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairieC, 5% - 20%
valley and foothill grasslandA, > 50%
Great Basin grassland
vernal poolD, < 5%
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 woodlandA, > 50%
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forest
closed cone coniferous forest
lower montane coniferous forestC, 5% - 20%
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

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