Plant Assessment Form

Agrostis stolonifera

Synonyms: Agrostis alba L. var palustris (Huds.), Agrostis maritima Lam., Agrostis palustria Huds., Agrostis stolonifera L. var. compacta

Common Names: creeping bent; carpet bent; redtop bent; seaside bentgrass

Evaluated on: 2/25/05

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

Carla Bossard
John Randall
Carri Pirosko
Dan Gluesenkamp
Gina Skurka
Brianna Richardson

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? Limited
Alert Status? No Alert
Documentation? 2 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U Reviewed Scientific Publication
Impact?
Four-part score UCUU Total Score
C
1.2 ?Impact on plant community C. Minor Reviewed Scientific Publication
1.3 ?Impact on higher trophic levels U. Unknown
1.4 ?Impact on genetic integrity U. Unknown
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Other Published Material
Invasiveness?
Total Points
11 Total Score B
2.2 ?Local rate of spread with no management U. Unknown
2.3 ?Recent trend in total area infested within state C. Stable Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
A. High Other Published Material
2.5 ?Potential for human-caused dispersal A. High Other Published Material
2.6 ? Potential for natural long-distance dispersal C. Rare Other Published Material
2.7 ?Other regions invaded C. Already invaded Observational
3.1 ?Ecological amplitude/Range
(see Worksheet C)
B. Moderate 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? U Reviewed Scientific Publication
Identify ecosystem processes impacted:

Sources of information:

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

Grows into dense 5-20cm thick sward that completely covers the soil (1), but very large infestations have not been reported.


Sources of information:

1. Collet, C., H. Frochot, and J-M Guekhl. 1996. Growth dynamics and water uptake of two forest grasses differing in their growth strategy and potentially competing with forest seedlings. Canadian Journal of Botany 74(10): 1555-1561.


Question 1.3 Impact on higher trophic levels? U
Identify type of impact or alteration:

Sources of information:

Question 1.4 Impact on genetic integrity? U

There are 15 native bentgrass species in California and several introduced. No information on hybridization.


Sources of information:

Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA enter text here


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

Inhabits ditches, lake and pond margins, salt and freshwater marshes, disturbed riparian areas.


Sources of information:

DiTomaso and Healy in prep.


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

no information


Sources of information:

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

Appears to be fairly static in its invasiveness and spread.


Sources of information:

DiTomaso, observational.


Question 2.4 Innate reproductive potential? A Other Published Material
Describe key reproductive characteristics:

Perennial with creeping stolons to 1m long. A widespread, variable species that consists of a complex of polyploid biotypes. Reproduces vegetatively from creeping stolons and by seed. Seeds probably remain viable for many years under field conditions. Tolerates close mowing.


Sources of information:

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


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

Cultivars used for turf and sod. Seeds can disperse with human activities.


Sources of information:

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


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

Seeds can disperse with water, mud, and animals, but water dispersal would be most important for long distance transport along rivers and streams.


Sources of information:

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


Question 2.7 Other regions invaded? C Observational
Identify other regions:

The weedy biotype found in California is native to Europe. One biotype may be native to the northern U.S. Present in most contiguous states (1). Likely inhabits similar environments where it is weedy elsewhere.


Sources of information:

1. DiTomaso and Healy in prep., DiTomaso, observational.


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

Present in northwestern California, Cascade Range, northern Sierra Nevada, central-western region, southwestern region except Channel Islands to 1000m. Inhabits ditches, lake and pond margins, salt and freshwater marshes, disturbed riparian areas. Facultative wetland indicator species. Some biotypes tolerate salinity, serpentine soil, or high levels of copper or zinc (1). An heliophilic species specific to well-watered and clay soils (2).


Sources of information:

1. DiTomaso and Healy in prep.
2. Collett et al. 1996


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

Not a common escape in California.


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 Yes
Fragments easily and fragments can become established elsewhere Unknown
Resprouts readily when cut, grazed, or burned Yes
Total points: 6
Total unknowns: 2
Total score: A?

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 scrub
coastal scrub
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 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 woodlandD, < 5%
riparian scrub (incl.desert washes)
Woodlandcismontane woodland
piñon and juniper woodland
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): B
Distribution (highest score): D

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