Plant Assessment Form

Rubus armeniacus

Synonyms: Rubus discolor Weihe & Nees., Rubus procerus Muller, Rubus grabowskii Weihe ex Gunther et al., Rubus praecox Bertol.

Common Names: Himalayan blackberry

Evaluated on: 5/12/04

List committee review date: 27/08/2004

Re-evaluation date:

Evaluator(s)

Peter J. Warner
California Department of Parks & Recreation, Mendocino District
P. O. Box 603, Little River, CA 95456
707.937.9172 (w), 707.937.2278 (h)
pwarner@mcn.org

List commitee members

Cynthia Roye
Peter Warner
Joe DiTomaso
John Randall
Alison Stanton
Jake Sigg

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? High
Alert Status? No Alert
Documentation? 3 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes B Other Published Material
Impact?
Four-part score BAAC Total Score
A
1.2 ?Impact on plant community A. Severe Other Published Material
1.3 ?Impact on higher trophic levels A. Severe Other Published Material
1.4 ?Impact on genetic integrity C. Minor/Low Other Published Material
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Other Published Material
Invasiveness?
Total Points
17 Total Score A
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 B. Increasing less rapidly Other Published Material
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 A. Frequent 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 Other Published Material

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 Other Published Material
Identify ecosystem processes impacted:

Shading of subcanopy vegetation and ground layers, explosively flammable, reduces soil moisture. Temporary or manageable, non-permanent impacts if plants are removed.


Sources of information:

1. Hoshovsky, MC. 2000. Rubus discolor in Bossard, CC, JM Randall, and MC Hoshovsky. Invasive Plants of California's Wildlands. UC Press, Berkeley. pp. 277-281.
2. US Department of the Interior, Bureau of Land Management @ www.cablm.gov/redding/redrudi.html.
3. Personal observations, Cynthia Roye, 2004.
4. Personal observations, Jake Sigg, 2004.


Question 1.2 Impact on plant community composition,
structure, and interactions?
A Other Published Material
Identify type of impact or alteration:

shades and outcompetes native species for light (1,2,3); may be limiting dispersal of native Rubus spp. by pre-emptive competition (4) pre-empts virtually all other species from its subcanopy (1,2,3); inference (4)


Sources of information:

1. Hoshovsky, MC. 2000. Rubus discolor in Bossard, CC, JM Randall, and MC Hoshovsky. Invasive Plants of California's Wildlands. UC Press, Berkeley. pp. 277-281.
2. US Department of the Interior, Bureau of Land Management @ www.cablm.gov/redding/redrudi.html.
3. Oahu Invasive Species Committee @ www.hear.org/oisc/oisc_target_species/rubus_ellipticus.htm
4. Warner, PJ. 2004. personal inference.


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

can create barriers to water access (1,2); spines can cause injury (1,2); wildlife value of forage, nesting, and shelter (3); displacement of native plant species likely to have undocumented impacts on alternative forage and shelter availability (4). Attracts rats, which can have a significant impact on bird populations. overall negative cumulative impacts on higher trophic levels considered moderate, since forage and shleter values provide some benefits. However, undocumented negative arising from displacement of native plant species and resulting impacts on forage and shelter for wildlife and overall species and population viability could be considerable.


Sources of information:

1. Hoshovsky, MC. 2000. Rubus discolor in Bossard, CC, JM Randall, and MC Hoshovsky. Invasive Plants of California's Wildlands. UC Press, Berkeley. pp. 277-281.
2. US Department of the Interior, Bureau of Land Management @ www.cablm.gov/redding/redrudi.html.
3. U.S. Departmen of Agriculture, Forest Service @ www.fs.fed.us/database/feis/plants/shrub/rubdis/all.html
4. Warner, PJ. 2004. Personal inference.
5. Underwood, Dessie. Research at Cosumnes Preserve on rat and bird populations.


Question 1.4 Impact on genetic integrity? C Other Published Material

Many native Rubus cogeners in California; however, specific impacts are unknown. Genus is well known for producing hybrids; habitat for R. armeniacus overlaps considerably with native taxa; probability for hybridization cited (1)


Sources of information:

Hickman, JC. 1993. The Jepson Manual: Higher Plants of California (2nd printing). UC Press, Berkeley. p. 974.
Observational John Randall, Peter Warner, Jake Sigg. 2004.


Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
A Other Published Material
Describe role of disturbance:

establishes readily in areas disturbed naturally, especially by flooding (1), or by humans, including overgrazed riparian corridors, fallow agricultural areas (1,2,3) Most aggressive in disturbed areas, but plants will grow in areas without substantial disturbance.


Sources of information:

1. Hoshovsky, MC. 2000. Rubus discolor in Bossard, CC, JM Randall, and MC Hoshovsky. Invasive Plants of California's Wildlands. UC Press, Berkeley. pp. 277-281.
2. U.S. Departmen of Agriculture, Forest Service @ www.fs.fed.us/database/feis/plants/shrub/rubdis/all.html
3. Hoshovsky, MC. (date of publication unknown). Element stewardship abstract for Rubus discolor (Rubus procerus) Himalayan blackberry. The Nature Conservancy, Arlington VA @ www.tncweeds.ucdavis.edu/esadocs/documnts/rubudis.pdf.


Question 2.2 Local rate of spread with no management? A Other Published Material
Describe rate of spread:

Species capable of vegetative reproduction by cane growth and rooting at tips up to 3.3m/year (1); a relatively small stand can expand in area many times within a few years (2). Vegetative reproduction by stem elongation ad rooting provide mechanism for rapid growth in area of a clonal stand.


Sources of information:

1. Hoshovsky, MC. (date of publication unknown). Element stewardship abstract for Rubus discolor (Rubus procerus) Himalayan blackberry. The Nature Conservancy, Arlington VA @ www.tncweeds.ucdavis.edu/esadocs/documnts/rubudis.pdf.
2. Warner, PJ. 2004. Personal observations of R. armeniacus infestations in Marin, Sonoma, Mendocino Counties, 1994-2004.


Question 2.3 Recent trend in total area infested within state? B Other Published Material
Describe trend:

No reliable data, but frequent observations of nascent patches suggest that continued expansion of habitats infested is likely (1), although species is already widely distributed in CA (2) Many habitats suitable for invasion are already infested, but locally, opportunities for additional patch establishement are abundant.


Sources of information:

1. Warner, PJ. 2004. Personal observations of R. armeniacus infestations in Marin, Sonoma, Mendocino Counties, 1994-2004.
2. CalFlora @ www.calflora.org


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

Prolific sexual reproduction producing seed; tenacious vegettative reproduction through stem elongation and nodal rooting; various forms of asexual fruit production (parthenogenesis, pseudogamy, parthenocarpy) (1,2,3) species has evolved a number or reproductive strategies


Sources of information:

1. Hoshovsky, MC. 2000. Rubus discolor in Bossard, CC, JM Randall, and MC Hoshovsky. Invasive Plants of California's Wildlands. UC Press, Berkeley. pp. 277-281.
2. U.S. Departmen of Agriculture, Forest Service @ www.fs.fed.us/database/feis/plants/shrub/rubdis/all.html
3. Hoshovsky, MC. (date of publication unknown). Element stewardship abstract for Rubus discolor (Rubus procerus) Himalayan blackberry. The Nature Conservancy, Arlington VA @ www.tncweeds.ucdavis.edu/esadocs/documnts/rubudis.pdf.


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

ingestion of seeds (1); planting of canes (2) for fruit production, erosion control; land clearing and debris disposal (1) humans enjoy blackberries; we plant them, we eat them, we disperse seeds and stems


Sources of information:

1. Warner, PJ. 2004. Personal observations of R. armeniacus infestations in Marin, Sonoma, Mendocino Counties, 1994-2004.
2. U.S. Departmen of Agriculture, Forest Service @ www.fs.fed.us/database/feis/plants/shrub/rubdis/all.html


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

mammal, bird ingestion of fruits; gravity; water (1,2,3) animal ingestion and riparian water flow provide numerous opportunities for long-distance dispersal


Sources of information:

1. Hoshovsky, MC. 2000. Rubus discolor in Bossard, CC, JM Randall, and MC Hoshovsky. Invasive Plants of California's Wildlands. UC Press, Berkeley. pp. 277-281.
2. U.S. Departmen of Agriculture, Forest Service @ www.fs.fed.us/database/feis/plants/shrub/rubdis/all.html
3. Hoshovsky, MC. (date of publication unknown). Element stewardship abstract for Rubus discolor (Rubus procerus) Himalayan blackberry. The Nature Conservancy, Arlington VA @ www.tncweeds.ucdavis.edu/esadocs/documnts/rubudis.pdf.


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

widespread in Pacific Northwest, Birtish Columbia, North American northeast, Europe, especially in moist, disturbed habitats, such as riparian zones, marshes, estuaries, seeps, roadsides, wet swales in woodlands, forests; also noted as invasive in Hawai'i (1,2) has been established in CA for over a century (1), and is well distributed in the state; prbably has invaded most suitable hatiats


Sources of information:

1. Hoshovsky, MC. 2000. Rubus discolor in Bossard, CC, JM Randall, and MC Hoshovsky. Invasive Plants of California's Wildlands. UC Press, Berkeley. pp. 277-281.
2. Oahu Invasive Species Committee @ www.hear.org/oisc/oisc_target_species/rubus_ellipticus.htm
3. University of British Columbia @ www.geog.ub.ca/richmond/city/vasiveplants.htm


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

Widespread in cismontane CA, particularly riparian zones, wetlands, moist areas in woodlands, forests, grasslands (2,3,4) 1885: Luther Burbank (1)


Sources of information:

1. Botanical Electronic News @ www.ou.edu/cas/botany-micro/ben/ben230.html
2. Hoshovsky, MC. 2000. Rubus discolor in Bossard, CC, JM Randall, and MC Hoshovsky. Invasive Plants of California's Wildlands. UC Press, Berkeley. pp. 277-281.
3. CalFlora @ www.calflora.org
4. Warner, PJ. 2004. Personal observations of R. armeniacus infestations in Marin, Sonoma, Mendocino Counties, 1994-2004.


Question 3.2 Distribution/Peak frequency? A Other Published Material
Describe distribution:

widespread in mesic and hydric ecosystems in cismontane northern California (1,2,3)


Sources of information:

1. CalFlora @ www.calflora.org
2. Warner, PJ. 2004. Personal observations of R. armeniacus infestations in Marin, Sonoma, Mendocino Counties, 1994-2004.
3. Hoshovsky, MC. 2000. Rubus discolor in Bossard, CC, JM Randall, and MC Hoshovsky. Invasive Plants of California's Wildlands. UC Press, Berkeley. pp. 277-281.


Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less No
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 Yes
Seeds remain viable in soil for three or more years Yes
Viable seed produced with both self-pollination and cross-pollination Yes
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes Yes
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned Yes
Total points: 9
Total unknowns: 0
Total score: A?

Related traits:

species reproduces by sexual reproduction, parthenogenesis, pseudogamy, and parthenocarpy

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
estuariesB, 20% - 50%
Dunescoastal
desert
interior
Scrub and Chaparralcoastal bluff scrub
coastal scrubB, 20% - 50%
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 prairieB, 20% - 50%
valley and foothill grassland
Great Basin grassland
vernal pool
meadow and seepC, 5% - 20%
alkali playa
pebble plain
Bog and Marshbog and fenC, 5% - 20%
marsh and swampB, 20% - 50%
Riparian and Bottomland habitatriparian forestB, 20% - 50%
riparian woodlandA, > 50%
riparian scrub (incl.desert washes)C, 5% - 20%
Woodlandcismontane woodlandC, 5% - 20%
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forestC, 5% - 20%
North Coast coniferous forestC, 5% - 20%
closed cone coniferous forestB, 20% - 50%
lower montane coniferous forestD, < 5%
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

  • CA Floristic Province
  • Cascade Range
  • Central West
  • Great Valley
  • Northwest
  • Sierra Nevada
  • Southwest
  • Modoc Plateau
  • Sierra Nevada East
  • Desert Province
  • Mojave Desert
  • Sonoran Desert