Plant Assessment Form

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Elaeagnus angustifolia

Synonyms: Elaeagnus angustifolius

Common Names: Russian olive; oleaster

Evaluated on: 2/9/05

List committee review date: 11/03/2005

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

List committee members

Joe DiTomaso
John Randall
Carla Bossard

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate

Alert Status? No Alert

Documentation? 2 out of 5

Score

Documentation

1.1

?Impact on abiotic ecosystem processes

B. Moderate

Other Published Material

Impact?
Four-part score BABD Total Score
B

1.2

?Impact on plant community

A. Severe

Reviewed Scientific Publication

1.3

?Impact on higher trophic levels

B. Moderate

Reviewed Scientific Publication

1.4

?Impact on genetic integrity

D. None

Reviewed Scientific Publication

2.1

?Role of anthropogenic and natural disturbance in establishment

A. Severe

Reviewed Scientific Publication

Invasiveness?
Total Points
18 Total Score A

2.2

?Local rate of spread with no management

A. Increases rapidly

Reviewed Scientific Publication

2.3

?Recent trend in total area infested within state

B. Increasing less rapidly

2.4

?Innate reproductive potential
(see Worksheet A)

A. High

2.5

?Potential for human-caused dispersal

A. High

2.6

? Potential for natural long-distance dispersal

A. Frequent

2.7

?Other regions invaded

C. Already invaded

3.1

?Ecological amplitude/Range
(see Worksheet C)

A. Widespread

Distribution?
Total Score B

3.2

?Distribution/Peak frequency
(see Worksheet C)

D. Very low

Reviewed Scientific Publication

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? Consider the impact on the natural range and variation of abiotic ecosystem processes and system-wide parameters in ways that significantly diminish the ability of native species to survive and reproduce. Alterations that determine the types of communities that can exist in a given area are of greatest concern. Examples of abiotic processes include: - fire occurrence, frequency, and intensity; - geomorphological changes such as erosion and sedimentation rates; - hydrological regimes, including soil water table; - nutrient and mineral dynamics, including salinity, alkalinity, and pH; - light availability (e.g. when an aquatic invader covers an entire water body that would otherwise be open). Select the one letter below that best describes this species' most severe impact on an abiotic ecosystem process: A. Severe, possibly irreversible, alteration or disruption of an ecosystem process. B. Moderate alteration of an ecosystem process. C. Minor alteration of an ecosystem process. D. Negligible perceived impact on an ecosystem process. U. Unknown.	B Other Published Material
Identify ecosystem processes impacted: Alters nutrient cycling and system hydrology by spreading througout woodland, connecting lowland riparian forests with more open, upland areas. High rate of evapotranspiration increases water loss compared to native trees. Eventually changes riparian sites into dry uplands. Dense thickets of Russian olive can increase fuel loads for wildfire (1). Sources of information: 1. Tu, M. 2003. Element Stewardship Abstract: Eleagnus angustifola. The Nature Conservancy, Arlington, VA. Accessed online: http://tncweeds.ucdavis.edu
Question 1.2 Impact on plant community composition, structure, and interactions? Consider the cumulative ecological impact of this species to the plant communities it invades. Give more weight to changes in plant composition, structure, and interactions that involve rare or keystone species or rare community types. Examples of severe impacts include: - formation of stands dominated (>75% cover) by the species; - occlusion (>75% cover) of a native canopy, including a water surface, that eliminates or degrades layers below; - significant reduction or extirpation of populations of one or more native species. Examples of impacts usually less than severe include: - reduction in propagule dispersal, seedling recruitment, or survivorship of native species; - creation of a new structural layer, including substantial thatch or litter, without elimination or replacement of a pre-existing layer; - change in density or depth of a structural layer; - change in horizontal distribution patterns or fragmentation of a native community; - creation of a vector or intermediate host of pests or pathogens that infect native plant species. Select the one letter below that best describes this species' impact on community composition, structure and interactions: A. Severe alteration of plant community composition, structure, or interactions. B. Moderate alteration of plant community composition. C. Minor alteration of community composition. D. Negligible impact known; causes no perceivable change in community composition, structure, or interactions. U. Unknown.	A Reviewed Scientific Publication
Identify type of impact or alteration: Forms dense monocultures. Shades out cottonwood seedlings. Over time, will replace tall cottonwood trees with shorter olive trees. Can establish over a wider range of sites than cottonwood (1). Alters the course of plant succession (2). Sources of information: 1. Shafroth, P. B., G. T. Auble, and M. L. Scott. 1995. Germination and establishment of the native plains cottonwood (Populus deltoides Marshall subsp. monilifera) and the exotic Russian-olive (Elaeagnus angustifolia L.) Conservation Biology. 9:1169-1175 2. Tu 2003
Question 1.3 Impact on higher trophic levels? Consider the cumulative impact of this species on the animals, fungi, microbes, and other organisms in the communities that it invades. Although a non-native species may provide resources for one or a few native species (e.g. by providing food, nesting sites, etc.), the ranking should be based on the species' net impact on all native species. Give more weight to changes in composition and interactions involving rare or keystone species or rare community types. Examples of severe impacts include: - extirpation or endangerment of an existing native species or population; - elimination or significant reduction in native species' nesting or foraging sites, cover, or other critical resources (i.e., native species habitat), including migratory corridors. Examples of impacts that are usually less than severe include: - minor reduction in nesting or foraging sites, cover, etc. for native animals; - minor reduction in habitat connectivity or migratory corridors; - interference with native pollinators; - injurious components, such as awns or spines that damage the mouth and gut of native wildlife species, or production of anti-digestive or acutely toxic chemical that can poison native wildlife species. Select the one letter below that best describes this species' impact on community composition and interactions: A. Severe alteration of higher trophic populations, communities, or interactions. B. Moderate alteration of higher trophic level populations, communities, or interactions. C. Minor alteration of higher trophic level populations, communities or interactions. D. Negligible impact; causes no perceivable change in higher trophic level populations, communities, or interactions. E. Unknown.	B Reviewed Scientific Publication
Identify type of impact or alteration: Has both positive and negative impacts on wildlife. Provides food and cover for some species (1, 2). In the Rocky Mountains, some riparian birds occurred frequently in monotypic Russian olive stands, but species that are obligate residents of lowland riparian tracts (northern flicker, house wren, cedar waxwing, warbling vireo, black-headed grosbeak) were absent from Russian olive stands (2). Russian olive stands supported avian communities intermediate in species richness and alpha diversity to native riparian and upslope areas (2). Sources of information: 1. Olson, T. E., and F. L. Knopf. 1986. Naturalization of Russian-olive in the western United States. Western Journal of Applied Forestry. 1: 65-69 2. Knopf, F. L., and T. E. Olson. 1984. Naturalization of Russian-olive: Implications to Rocky Mountain wildlife. Wildl. Soc. Bull. 12 289-298.
Question 1.4 Impact on genetic integrity? Consider whether the species can hybridize with and influence the proportion of individuals with non-native genes within populations of native species. Mechanisms and possible outcomes include: - production of fertile or sterile hybrids that can outcompete the native species; - production of sterile hybrids that lower the reproductive output of the native species. Select the one letter below that best describes this species' impact on genetic integrity: A. Severe (high proportion of individuals). B. Moderate (medium proportion of individuals). C. Minor (low proportion of individuals). D. No known hybridization. U. Unknown.	D Reviewed Scientific Publication
none No native Eleagnus in California. 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? Assess this species' dependence on disturbance: both human and natural: for establishment in wildlands. Examples of anthropogenic disturbances include: - grazing, browsing, and rooting by domestic livestock and feral animals; - altered fire regimes, including fire suppression; - cultivation; - silvicultural practices; - altered hydrology due to dams, diversions, irrigation, etc.; - roads and trails; - construction; - nutrient loading from fertilizers, runoff, etc. Examples of natural disturbance include: - wildfire; - floods; - landslides; - windthrow; - native animal activities such as burrowing, grazing, or browsing. Select the first letter in the sequence below that describes the ability of this species to invade wildlands: A. Severe invasive potential: this species can establish independent of any known natural or anthropogenic disturbance. B. Moderate invasive potential: this species may occasionally establish in undisturbed areas but can readily establish in areas with natural disturbances. C. Low invasive potential: this species requires anthropogenic disturbance to establish. D. No perceptible invasive potential: this species does not establish in wildlands (though it may persist from former cultivation). U. Unknown.	A Reviewed Scientific Publication
Describe role of disturbance: Does not appear to require disturbance to establish because seeds can germinate on undisturbed soils. Sources of information: 1. Lesica and Miles 1999
Question 2.2 Local rate of spread with no management? Assess this species' rate of spread in existing localized infestations where the proportion of available habitat invaded is still small when no management measures are implemented. Select the one letter below that best describes the rate of spread: A. Increases rapidly (doubling in <10 years) B. Increases, but less rapidly C. Stable D. Declining U. Unknown	A Reviewed Scientific Publication
Describe rate of spread: Can spread rapidly. Sources of information: 1. Olson and Knopf. 1986.
Question 2.3 Recent trend in total area infested within state? Assess the overall trend in the total area infested by this species statewide. Include current management efforts in this assessment and note them. Select the one letter below that best describes the current trend: A. Increasing rapidly (doubling in total range statewide in <10 years) B. Increasing, but less rapidly C. Stable D. Declining U. Unknown	B
Describe trend: Not spreading as fast as in southwestern states. Sources of information: John Randall, The Nature Conservancy, Invasive Species Initiative, pers. obs. Joe DiTomaso, Weed Science program, UC-Davis, pers. obs.
Question 2.4 Innate reproductive potential? Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.	A
Describe key reproductive characteristics: Long-lived tree. Bears fruit at three to five years. Seeds can germinate anytime between fall and spring, and remain viable for up to three years. Can reproduce sexually or vegetatively. Seedlings are shade-tolerant. Numerous root suckers are produced at the root crown after disturbance or damage to aboveground tree from fire, cutting, or girdling (1). Sources of information: 1. Tu 2003
Question 2.5 Potential for human-caused dispersal? Assess whether this species is currently spread: or has high potential to be spread: by direct or indirect human activity. Such activity may enable the species to overcome natural barriers to dispersal that would not be crossed otherwise, or it may simply increase the natural dispersal of the species. Possible mechanisms for dispersal include: - commercial sales for use in agriculture, ornamental horticulture, or aquariums; - use as forage, erosion control, or revegetation; - presence as a contaminant (seeds or propagules) in bulk seed, hay, feed, soil, packing materials, etc.; - spread along transportation corridors such as highways, railroads, trails, or canals; - transport on boats or boat trailers. Select the one letter below that best describes human-caused dispersal and spread: A. High: there are numerous opportunities for dispersal to new areas. B. Moderate: human dispersal occurs, but not at a high level. C. Low: human dispersal is infrequent or inefficient. D. Does not occur. U. Unknown.	A
Identify dispersal mechanisms: Planted as a windbreak tree and for wildlife enhancement (1), as well as for erosion control and highway beautification (2). Found in Cal-IPC nursery survey 2004. Sources of information: 1. Lesica, P., and S. Miles. 1999 Russian olive invasion into cottonwood forests along a regulated river in north-central Montana. Canadian Journal of Botany. 77:1077-1083. 2. Olson and Knopf 1986
Question 2.6 Potential for natural long-distance dispersal? We have chosen 1 km as the threshold of "long-distance." Assess whether this species is frequently spread, or has high potential to be spread, by animals or abiotic mechanisms that can move seed, roots, stems, or other propagules this far. The following are examples of such natural long-distance dispersal mechanisms: - the species' fruit or seed is commonly consumed by birds or other animals that travel long distances; - the species' fruits or seeds are sticky or burred and cling to feathers or hair of animals; - the species has buoyant fruits, seeds, or other propagules that are dispersed by flowing water; - the species has light propagules that promote long-distance wind dispersal; - The species, or parts of it, can detach and disperse seeds as they are blown long distances (e.g., tumbleweed). Select the one letter below that best describes natural long-distance dispersal and spread: A. Frequent long-distance dispersal by animals or abiotic mechanisms. B. Occasional long-distance dispersal by animals or abiotic mechanisms. C. Rare dispersal more than 1 km by animals or abiotic mechanisms. D. No dispersal of more than 1 km by animals or abiotic mechanisms. U. Unknown.	A
Identify dispersal mechanisms: Fruits dispersed by birds (1), but transport by water is probably more important because this is a riparian species (2). Sources of information: 1. Lesica and Miles 1999 2. Joe DiTomaso, UC Davis, pers. obs.
Question 2.7 Other regions invaded? Assess whether this species has invaded ecological types in other states or countries outside its native range that are analogous to ecological types not yet invaded in your state (see Worksheets B, C, and D for California, Arizona, and Nevada, respectively, in Part IV for lists of ecological types). This information is useful in predicting the likelihood of further spread within your state. Select the one letter below that best describes the species' invasiveness in other states or countries, outside its native range. A. This species has invaded 3 or more ecological types elsewhere that exist in your state and are as yet not invaded by this species (e.g. it has invaded Mediterranean grasslands, savanna, and maquis in southern Europe, which are analogous to California grasslands, savanna, and chaparral, respectively). B. Invades 1 or 2 ecological types that exist but are not yet invaded in your state. C. Invades elsewhere but only in ecological types that it has already invaded in the state. D. Not known as an escape anywhere else. U. Unknown.	C
Identify other regions: Naturalized in riparian areas throughout the U.S (1), primarily in western states (2). Can invade both upland and riparian bottomlands (3). Sources of information: 1. Lesica and Miles 1999 2. Olson and Knopf 1986 3. Tu 2003
Section 3: Distribution
Question 3.1 Ecological amplitude/Range? Refer to Worksheet C and select the one letter below that indicates the number of different ecological types that this species invades. A. Widespread: the species invades at least three major types or at least six minor types. B. Moderate: the species invades two major types or five minor types. C. Limited: the species invades only one major type and two to four minor types. D. Narrow: the species invades only one minor type. U. Unknown.	A
Present in Inyo, Tulare, and San Diego Counties (1). Riparian areas, flood plains, grasslands, roadsides, fencerows, seasonally moist pastures, ditches, and other disturbed sites. Often inhabits seasonally moist areas and sites near farmlands. Grows under a wide range of environmental conditions, including clay, sandy, and fairly alkaline or saline soils. Grows best in inland areas with warm summers and cold winters. Tolerates drought, high water tables, and temperatures well below freezing (to -45 degrees C or -50 degrees F) to as high as 46 degrees C (115 degrees F). San Joaquin Valley, San Francisco Bay region, eastern Sierra Nevada, Mojave Desert, mostly to 1500 m. Western states, central states, most northeastern and eastern states, a few southern states (2). Sources of information: 1. USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA 2. DiTomaso, J., and E. Healy. Weeds of California and Other Western States. in prep..
Question 3.2 Distribution/Peak frequency? To assess distribution, record the letter that corresponds to the highest percent infested score entered in Worksheet C for any ecological type.	D Reviewed Scientific Publication
Describe distribution: Sources of information:

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	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:	6
Total unknowns:	0
Total score:	A? Scoring Criteria for Worksheet A A. High reproductive potential (6 or more points). B. Moderate reproductive potential (4-5 points). C. Low reproductive potential (3 points or less and less than 3 Unknowns). U. Unknown (3 or fewer points and 3 or more Unknowns).

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? A means >50% of type occurrences are invaded; B means 20% to 50%; C means 5% to 20%; D means present but <5%; U means unknown (unable to estimate percentage of occurrences invaded)
Marine Systems	marine systems
Freshwater and Estuarine	lakes, ponds, reservoirs
Aquatic Systems	rivers, streams, canals
Aquatic Systems	estuaries
Dunes	coastal
	desert
	interior
Scrub and Chaparral	coastal 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 Communities	coastal prairie
	valley and foothill grassland
	Great Basin grassland	D, < 5%
	vernal pool
	meadow and seep	D, < 5%
	alkali playa	D, < 5%
	pebble plain
Bog and Marsh	bog and fen
Bog and Marsh	marsh and swamp
Riparian and Bottomland habitat	riparian forest
	riparian woodland
	riparian scrub (incl.desert washes)	D, < 5%
Woodland	cismontane woodland
	piñon and juniper woodland
	Sonoran thorn woodland
Forest	broadleaved upland forest
	North Coast coniferous forest
	closed cone coniferous forest
	lower montane coniferous forest
	upper montane coniferous forest
	subalpine coniferous forest
Alpine Habitats	alpine boulder and rock field
Alpine Habitats	alpine dwarf scrub
	Amplitude (breadth):	B
	Distribution (highest score):	D

Infested Jepson Regions

Click here for a map of Jepson regions

Central West
Great Valley
Northwest
Sierra Nevada
Southwest
Modoc Plateau
Sierra Nevada East
Desert Province
Mojave Desert
Sonoran Desert