Plant Assessment Form

Prunus cerasifera

Synonyms: None known

Common Names: cherry plum; Myrobalan plum; Pissard plum; purpleleaf plum

Evaluated on: 8/7/05

List committee review date: 15/08/2005

Re-evaluation date:

Evaluator(s)

Peter J. Warner
California Department of Parks and Recreation; CNPS
P. O. Box 603, Little River, CA 95456
(707) 937-9172 (w); (707) 937-278 (h)
pwarn@parks.ca.gov

List commitee members

Peter Warner
Joe DiTomaso
Jake Sigg
Cynthia Roye

General Comments

This assessment primarily based on personal observations of evaluator; more information needed for most questions.

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 UCCU Total Score
C
1.2 ?Impact on plant community C. Minor Observational
1.3 ?Impact on higher trophic levels C. Minor Observational
1.4 ?Impact on genetic integrity U. Unknown
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Observational
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 B. Increasing less rapidly Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
C. Low Observational
2.5 ?Potential for human-caused dispersal A. High Observational
2.6 ? Potential for natural long-distance dispersal C. Rare Observational
2.7 ?Other regions invaded C. Already invaded Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
A. Widespread Observational
Distribution?
Total Score B
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:

No information.


Sources of information:

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

In some infestations, minor displacement of native shrubs or trees by occupying canopy space; may have indirect impact on seed dispersal of native species Fruits are large, attractive, and consumed by birds, especially corvids, and frugivorous mammals, e.g., raccoons.


Sources of information:

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

Fruits are edible for birds, mammals, reptiles (?); tree trunks and branches often armored with stout thorns Fruit consumption: positive for frugivores; spines may cause injuries to some animals


Sources of information:

Warner, PJ. 1994-2005. Personal observations in San Mateo, Marin, Sonoma, Mendocino, Humboldt, Napa, and Shasta counties. 707/937-2278; corylus@earthlink.net


Question 1.4 Impact on genetic integrity? U

No documented hybrids with native species; Jepson Manual cites potential hybridization with other horticultural congeners (1); several native congeners, including some that are likely to occupy ecological types also invaded by P. cerasifera (e.g., P. virginiana, P. emarginata) No documented occurrences of hybridization with native Prunus species.


Sources of information:

1. Hickman, JC (ed.). 1993. The Jepson Manual: Higher Plants of California. Univeristy of California Press, Berkeley, CA


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

Some plants grow in relatively undisturbed sites (woodlands, riparian zones outside flood plains); natural (flooding) or anthropogenic (tilling, grazing) also appear to provide good germination conditions


Sources of information:

Warner, PJ. 1994-2005. Personal observations in San Mateo, Marin, Sonoma, Mendocino, Humboldt, Napa, and Shasta counties. 707/937-2278; corylus@earthlink.net


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

Spread appears largely opportunistic by frugivory and seed dispersal; only occasional observations of mature trees with saplings or seedlings nearby Most trees are not within thickets or larger stands, but growing alone or within a generally sparse population. With mature trees present, a rapidly spreading population would generally consist of large numbers of younger plants, and this is not the case.


Sources of information:

Warner, PJ. 1994-2005. Personal observations in San Mateo, Marin, Sonoma, Mendocino, Humboldt, Napa, and Shasta counties. 707/937-2278; corylus@earthlink.net


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

Substantial information lacking; however, occurrences are clearly underreported and undocumented. Range in CA extends well beyond those cited in Jepson Manual (1) and on CalFlora website (2). Personal observations indicate that slow spread into suitable habitats is occurring, andlikely to continue as individuals are intentionally introduced , or dispersed by wildlife, into new areas (3).


Sources of information:

1. Hickman, JC (ed.). 1993. The Jepson Manual: Higher Plants of California. Univeristy of California Press, Berkeley, CA
2. . CalFlora: Information on California plants for education, research and conservation. [web application]. 2005. Berkeley, California: The CalFlora Database [a non-profit organization]. Available: http://www.calflora.org/. (Accessed: Aug 07, 2005)
3. Warner, PJ. 1994-2005. Personal observations in San Mateo, Marin, Sonoma, Mendocino, Humboldt, Napa, and Shasta counties. 707/937-2278; corylus@earthlink.net


Question 2.4 Innate reproductive potential? C Observational
Describe key reproductive characteristics:

edible fruits, large seeds, perennial woody plant that will stump- and root-sprout following cutting of trunks (1) observed morphological characters (1)


Sources of information:

1. Warner, PJ. 1994-2005. Personal observations in San Mateo, Marin, Sonoma, Mendocino, Humboldt, Napa, and Shasta counties. 707/937-2278; corylus@earthlink.net


Question 2.5 Potential for human-caused dispersal? A Observational
Identify dispersal mechanisms:

Commercial sales; edible fruits with one large seed that is generally not consumed by humans The species and cultivars are still sold widely as an ornamental tree; fruits eaten by humans, so species can be dispersed when pits are disposed of in new areas.


Sources of information:

Question 2.6 Potential for natural long-distance dispersal? C Observational
Identify dispersal mechanisms:

Fruits and seeds consumed by birds and mammals Attractive and substantially sized fruits; however, range of individual animals eating fruits is usually not over 1 km


Sources of information:

Warner, PJ. 1994-2005. Personal observations in San Mateo, Marin, Sonoma, Mendocino, Humboldt, Napa, and Shasta counties. 707/937-2278; corylus@earthlink.net


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

Reported as invasive in Australian bush: South Australia, Queensland, New South Wales (1); in New Zealand (2); reported widely established in Pacific NW (3, 4, 5), Northeastern N. America (4) Australian bush similar in rainfall, temperatures to cismontane woodlands - not verified by evaluator; considered invasive in Oregon (3, 5), riparian areas, woodlands; P. cerasifera has probably invaded most analogous types in CA, until demonstrated otherwise.


Sources of information:

1. The Nature Conservancy. 2005. The Invasive Species Initiative. Rod Randall's Big Weed List. Online: http://tncweeds.ucdavis.edu/global/australia/pol.htm
2. New Zealand Dept. of Conservation. 2005. Online: http://www.doc.govt.nz/Regional-Info/010~Canterbury/005~Publications/Protecting-and-Restoring-Our-Natural-Heritage/021~Appendix-1.asp
3. Native Plant Society of Oregon, Emerald Chapter. Invasive Gardening and Landscaping Plants of the Southern Willamette Valley. Online: http://www.emeraldnpso.org/inv_ornmtls.html
4. USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center , Baton Rouge, LA 70874-4490 USA.
5. Haysom, KA, and ST Murphy. 2003. The status of invasiveness of forest tree species outside their natural habitat: a global review and discussion paper . Online: http://www.fao.org/documents/show_cdr.asp?url_file=/DOCREP/006/J1583E/J1583E10.htm (Appendices, Table 6)


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? A Observational

Primarily invades coastal scrub, lower elevation riparian zones, woodlands (1).


Sources of information:

1. Warner, PJ. 1994-2005. Personal observations in San Mateo, Marin, Sonoma, Mendocino, Humboldt, Napa, and Shasta counties. 707/937-2278; corylus@earthlink.net


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

Distribution probably underreported (1), but observed populations are few, sporadic, and limited in size; very locally, infestations can constitute a significant proportion of cover (2). Occurrences underreported, so personal observations used for this question (2).


Sources of information:

1. CalFlora: Information on California plants for education, research and conservation. [web application]. 2005. Berkeley, California: The CalFlora Database [a non-profit organization]. Available: http://www.calflora.org/. (Accessed: Aug 07, 2005)
2. Warner, PJ. 1994-2005. Personal observations in San Mateo, Marin, Sonoma, Mendocino, Humboldt, Napa, and Shasta counties. 707/937-2278; corylus@earthlink.net


Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less No
Dense infestations produce >1,000 viable seed per square meter No
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 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: 2
Total unknowns: 1
Total score: C?

Related traits:

RE: Seedling growth rate and potential for invasiveness: J. Bellingham, P., P. Duncan, R., G. Lee, W. & P. Buxton, R. (2004) Seedling growth rate and survival do not predict invasiveness in naturalized woody plants in New Zealand. Oikos106(2), 308-316. doi: 10.1111/j.0030-1299.2004.13171.x

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 scrubD, < 5%
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparralD, < 5%
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairie
valley and foothill grassland
Great Basin grassland
vernal pool
meadow and seep
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forestD, < 5%
riparian woodlandD, < 5%
riparian scrub (incl.desert washes)D, < 5%
Woodlandcismontane woodlandD, < 5%
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): A
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