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Species
Elaeagnus angustifolia var. orientalis (L.) Kuntze
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NCBI
EOL Text
Shrubs or small trees, 3-7(-10) m tall. Bark reddish brown; spines absent or sharp, 0.7-3 cm; young branches and both leaf surfaces silvery white, densely stellate-scaly, or adaxially grayish green or green and nearly without scales (var. virescens). Petiole 5-8 mm, 1/5-1/4 as long as blade; leaf blade oblong-lanceolate to linear-lanceolate, sometimes elliptic-lanceolate, ovate, or oblong-ovate, (2.5-)4-8(-10) × 0.4-3.2(-4) cm, adaxially dull green, or both surfaces silvery, with only white scales, base usually broadly cuneate, apex obtuse or subacute. Flowers 1-3 in axils of older leaves. Pedicel short, ca. 2 mm. Flowers fragrant, outside silvery white, with dense white scales and sparse small yellowish glands, inside yellow. Calyx tube campanulate or broadly campanulate (f. culta), ca. as long as limb, 5-6 × 2.5-3(-5) mm; lobes lanceolate, ovate, or triangular-lanceolate, slightly shorter than tube, inside yellow and glabrous, with sparse small brownish glands, distinctly 3-veined, apex ± acute. Filaments short; anthers oblong. Style base enclosed by tubular disk, curved in upper part, ca. as long as calyx. Drupe yellowish brown, globose-ovoid, globose, or subglobose (var. caspica), 0.7-2.5 × 0.5-1.3 cm, densely silvery scaly when young, subglabrous when mature; scales sparse, brownish; flesh sweet, mealy; stone oblong, oblong-ovoid, or narrowly cylindric (f. culta), both ends obtuse or pointed. Fl. May-Jun, fr. Aug-Oct. 2n = 28.
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Southeastern Europe and Western Asia
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More info for the terms: climax, density, fire suppression, fresh, fuel, hardwood, interference, natural, reclamation, root crown, shrubs, succession, tree
Russian-olive can establish at early successional stages, on bare, nutrient poor soils, and at later successional stages, under a well-developed canopy. It can persist into later stages of succession and change successional trajectories in the native communities that it invades. For example, it grows equally well beneath a dense cottonwood overstory, in almost pure stands of tamarisk, and in open areas along the Rio Grande River in New Mexico [33,91]. Knopf and Olson [103] observed naturalized Russian-olive individuals growing both within cottonwood floodplain forest and colonizing open wet meadows in several western states. It also occurs (as seedlings, saplings, and mature trees) in cottonwood forests of all ages, from the relatively open canopies of young (5- to 29-year-old) stands to very old (>80-year-old) stands along the Bighorn River in Montana [2].
Early succession: As a nitrogen-fixing, actinorrhizal plant, Russian-olive is likely to be an early-successional, pioneer species, able to colonize nitrogen-poor soils such as sandy, eroded mineral soils and wetlands [40]. As such, Russian-olive has often been used for reforestation and mine reclamation [24,31,90,144,193]. Russian-olive can establish in the postflood environment, but does not tend to dominate on sites with frequent flood disturbance [112].
There is no information in the literature regarding postfire succession in Russian-olive; however, observations by several workers indicate that Russian-olive sprouts from roots and root crown following aboveground damage [34,35,59,163,201], and is therefore likely to colonize on-site in the initial postfire community. If Russian-olive has a persistent seed bank and heat resistant or heat scarified seed, Russian-olive seedlings may also establish in the early postfire environment. More research is needed in this area of Russian-olive's reproductive ecology.
Late succession: The large seed size of Russian-olive provides resources to help seedlings establish under mature canopies. This allows Russian-olive regeneration in riparian areas to be decoupled from flood disturbance, unlike associated native species that depend on seasonal flooding for seedling establishment. Russian-olive is especially able to take advantage of the reduced levels of physical disturbance that characterize riparian habitats downstream from dams [23,96,156] (see Impacts).
Field observations indicate that Russian-olive is relatively tolerant of interference from established native vegetation, invading beneath woody overstories or within herbaceous vegetation [2,16,47,91,101,103,188]. Russian-olive has been recorded growing and reproducing in the understory of mature riparian forests along the Platte River in Nebraska [47], the Rio Grande River in New Mexico [33,60,66,91],and several rivers in Montana [2,111,112]. In fact, along the Marias and Yellowstone rivers in Montana, invasion of riparian communities often depends on proximity to established, mature trees [112].
Understory invasion in mid- and late-successional communities may alter the fuel structure of those communities (see Fire Ecology).
Shade tolerance: Russian-olive grows in either full sunlight or shade, but seems to prefer full sunlight (Cote and others 1988, as cited by [20]). It can establish and persist both in the shade of a mature overstory, in partial shade in margins and gaps, and in the open under full sunlight (see above). Shade tolerance may vary with latitude, although these limits are unclear. It has been suggested that Russian-olive does not thrive in shade in the northern Great Plains [72] or produce fruit in shade in "the north" [16]. Shade tolerance at northern latitudes may be related to age of Russian-olive and to moisture availability.
In eastern Montana, Akashi [2] observed Russian-olive seedlings at all overstory ages along the Bighorn River, though individuals seemed to persist in margins and gaps. On the Marias and Yellowstone rivers, Russian-olive was restricted to the cottonwood understory on dry high terraces but occurred with and without a cottonwood canopy on moist, lower-elevation terraces. Lower terraces along open and little-shaded channels, ditches and other relatively wet sites also provide habitat conducive to Russian-olive establishment and invasion [112].
Succession on Russian-olive-infested sites: Invasion of Russian-olive may alter the successional dynamics of riparian forests in several ways. In much of interior western North America, native riparian forests are dominated by pioneer species (primarily cottonwood and willow species) that are generally intolerant of shade [156] and do not establish within intact vegetation [95]. Russian-olive invades these communities by establishing beneath the canopy of native riparian trees and forming self-replacing stands. Russian-olive also establishes on flood-disturbed sites that are optimal for cottonwood recruitment.
On many western rivers, the absence of fluvial disturbance and lack of recruitment of native riparian trees allows Russian-olive to establish and eventually dominate on many sites at various successional stages [91,96,97,111,112,156]. Invasion of a cottonwood-dominated riparian forest by Russian-olive might proceed as follows on a river system with reduced flood magnitude and frequency: 1) Russian-olive seedlings establish under, or in margins or gaps of the canopy of an existing stand of cottonwoods; 2) as cottonwoods die, Russian-olive becomes the dominant overstory species; and 3) recruitment of Russian-olive seedlings continues in the shade of the new canopy, but cottonwood recruitment is restricted to the narrow, frequently-disturbed margins of the active stream channel, where annual high flows may bury or scour seedlings [156]. In addition to flow regulation, livestock grazing and trampling and selective harvesting by beaver limit recruitment of cottonwood on river floodplains in the northern Great Plains [111,113,140]. Shafroth and others [156] predict that Russian-olive will likely become a more prominent component of western landscapes as the cottonwood canopy of existing stands along regulated rivers is replaced by Russian-olive now present in the understory.
A review by Lesica and Miles [112] describes natural succession on the Marias and Yellowstone rivers in eastern Montana as follows: Cottonwood and willow establish from wind-borne seed on fresh, moist alluvium deposited by floods or channel meandering. Terraces with an understory of willow and a ground layer of hydrophytic plants are dominated by relatively young cottonwoods. As stands became older, periodic deposition raises the ground level higher above the water table. These older stands support an understory dominated by less hydric shrubs and grasses. After 100 to 200 years, cottonwoods die and are replaced by sagebrush or shade-tolerant green ash. Russian-olive may affect this riparian successional sequence by persisting and continuing to reproduce on these upper terraces and dominating the plant community after overstory cottonwoods die. Russian-olive was common along both rivers in stands with plants of many ages, suggesting that Russian-olive, but not cottonwood, recruitment continues to occur under established Russian-olive trees. Conversely, cottonwood establishment and dominance is not precluded on sites where flooding and new channel development continuously create new cottonwood habitat [15,112].
Concentrations of Russian-olive have been observed and mapped on most eastward flowing rivers in Montana, including unregulated rivers. Along the unregulated stretch of Milk River in Montana and Alberta, for example, Russian-olive outnumbers plains cottonwood on many sites between the Alberta/Montana border and the Fresno reservoir [140]. Cottonwood seed dispersal and germination do not appear to be a problem on unregulated reaches, as there were twice as many cottonwood as Russian-olive seedlings; however, successful cottonwood recruitment occurs only once in 5 to 10 years on the Milk River (Bradley and Smith 1986, as cited by [140]). In their study reach, Pearce and Smith [140] estimated attrition from seedling to sapling at 73% for cottonwood and 12% for Russian-olive. Based on present recruitment rates, it appears that Russian-olive will outnumber cottonwood in all size classes along the Milk River study reach within 10 years [140].
In the eastern Great Plains, cottonwood and willow are early successional species and are replaced by a self-sustaining, diverse hardwood forest as natural succession proceeds. In the western Great Plains, forest diversity decreases westward until only the early-successional tree species, cottonwood and willow, remain. Thus, in much of the western Great Plains, the climax native bottomland community is not forest, but shrubland or grassland. Therefore, maintenance of riparian forest in this area is dependent on regular physical disturbance. Since the 1800s, fire suppression and decreases in flow variability caused by water development have allowed Russian-olive and trees from the eastern Plains, especially green ash and eastern redcedar, to establish and persist in western bottomlands where shade-tolerant trees were formerly absent ([68], and references therein). Currier [47] provides an illustration and discussion of successional patterns on the Platte River in Nebraska. In some areas cottonwood dominates the forest canopy while Russian-olive establishes in the understory. Without cottonwood regeneration, Russian-olive, juniper, or mixed hardwood species eventually dominate the forest vegetation. Where Russian-olive establishes in grasslands in this area, sites become progressively elevated and drier over time as a result of overbank deposition, degradation of the river channel, and declines in river stage levels. The oldest Russian-olive stands were found on deep, well-drained soils, on which Russian-olive is apparently no longer able to establish [47].
Along the Rio Grande River in New Mexico, introduction of tamarisk and Russian-olive has changed the successional stages and ultimate dominants in many communities. Russian-olive replaces screwbean mesquite (Prosopis pubescens) in the understory of large Rio Grande cottonwood in phreatophyte communities along the Rio Grande south of Socorro [33], and may be replacing New Mexico olive on more northerly sites [128]. For more information on the effects of Russian-olive on succession in southwestern riparian areas see Habitat Types and Plant Communities.
Longevity: Along the Marias and Yellowstone rivers in eastern Montana, Russian-olive occurred in all size classes along both rivers, and most stands were multiple-aged. The oldest Russian-olives recorded were 36 and 40 years old on the Marias and Yellowstone rivers, respectively. Mean age of Russian-olive stands was 15.3 years on the Marias and 18.6 years on the Yellowstone. The oldest Russian-olive tree was as old or older than the oldest cottonwood in 39% and 14% of the stands on the Marias and Yellowstone rivers, respectively. In many cases these were stands where cottonwoods appeared to have established in fresh alluvium deposited on existing terraces with established Russian-olive [112].
Russian-olive has a low recruitment rate on eastern Montana rivers, and requires about 10 years to reach reproductive maturity; thus, invasion should proceed slowly compared to other aggressive herbaceous or shrubby weeds. Russian-olive has been present on both of the rivers studied for 36 to 40 years, but density in many stands is low [112].
This species is widely grown for its fruit ("Russian Olive," "Trebizond date"), and local cultivars have been developed. It also produces a valuable gum and useful timber, and is used for land reclamation. It can be invasive and has been declared a noxious weed in some parts of North America.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
Source | http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200014543 |
More info for the terms: achene, cover, density, root crown, shrub, tree
This description provides characteristics that may be relevant to fire ecology, and is not meant for identification. It is based on descriptions from syntheses, literature reviews ([16,49,96,172]), and florae ([46,74,86,94,115,161,196,198]). Keys for identification are available (e.g. [46,74,87,94,98,198]). Russian-olive can resemble some willow species with light green foliage, particularly sandbar willow. However, unlike Russian-olive, willows have inconspicuous flowers on erect stalks and small, wind-dispersed seeds [52]. It is important to be certain of identification before control measures are begun. In the eastern United States, Russian-olive may be confused with another nonnative invasive tree, autumn-olive (Elaeagnus umbellata). Mehrhoff and others [119] provide a descriptive comparison to distinguish these species.
Russian-olive is a perennial, tree or large multi-stemmed shrub. It has dark, smooth and sometimes shredding bark. Its branches are flexible and often armed with coarse thorns. Russian-olive is described as between 16 and 40 feet (5-12 m) tall, with trunks 4 to 20 inches (10-50 cm) thick. Borell [16] describes unpruned Russian-olive trees with 5 to 6 main stems starting near the ground and growing 12 to 20 feet (4-6 m). He suggests that if pruned to 1 stem, Russian-olive on good soil with plenty of water can grow to 40 feet (12 m) tall [16]. Field observations of naturalized Russian-olive in Montana indicate that it frequently branches at ground level, about 4 to 8 inches (10-20 cm) above the root crown in moist, unshaded sites; and branches further above ground level in drier, shaded habitats [112].
Russian-olive is deciduous, with alternate, petiolate leaves in small lateral clusters on twigs of the current year. Shape and vesture of Russian-olive leaves varies among individuals and within the canopy of single trees [102,196]. Descriptions of Russian-olive leaf size range from 0.8 to 4 inches (2-10 cm) long and 0.4 to 1.6 inches (1-4 cm) wide, and leaf shape is generally described as lanceolate to oblong and sometimes elliptic. Russian-olive produces fragrant flowers, 3-12 mm long, in small axillary clusters on the twigs of the current year. Fruits are drupe- or berry-like, oval-shaped, 0.4 to 0.8 inch (1-2 cm) long. A single, relatively large, 6-13 mm, oblong achene is enclosed in the fleshy fruit.
Roots: There are few descriptions of Russian-olive's root system in the literature. It is generally described as extensive [172] or deep, with many well-developed laterals. In deep soil with a calcareous clayey subsoil and water table below 15 feet (5 m), a 25-year-old, 26-foot-tall (8 m) Russian-olive had roots as long as 39 feet (12 m). A measure of root distribution by depth indicated that 23.4% of roots were in the 1st foot of soil, 26.5% in the 2nd foot, 31.6% in the 3rd foot, 18.3% in the 4th foot, and roots were rare below 4 feet (1.2 m) [203].
Depending on location and site conditions, Russian-olive roots sometimes associate with nitrogen-fixing bacteria (Frankia spp.)[117,149,179,206]. Cross-inoculation assays of Frankia isolates indicate that Frankia strains that infect Russian-olive may also infect plant species in the Rhamnaceae and Betulaceae families [17,40]. Because Russian-olive has been a common nursery plant, the scientific literature is rich with information on Frankia symbiosis and nitrogen fixation in Russian-olive, but this topic is beyond the scope of this review.
Growth habit/stand structure: Russian-olive's growth habits (e.g. stem and foliage density, canopy cover) seem to vary between plant communities in which it occurs, and depend on size and age of associated species, as well as history of disturbance of the site. In many sites Russian-olive grows in dense thickets with close spacing [16,47,59,81,140,168], sometimes with scattered mature cottonwood in the canopy [128]. On some southwestern riparian sites, dense, nearly monotypic stands of tamarisk and/or Russian-olive form a nearly continuous, closed canopy with no distinct overstory layer. Canopy height generally averages 16 to 33 feet (5-10 m), with canopy density uniformly high. The lower 6.5 feet (2 m) of vegetation often contains a tangle of dense, often dead, branches. Live foliage density may be relatively low from 0 to 6.5 feet (2 m) above ground, but increases higher in the canopy ([188] and references therein). Russian-olive may also grow as scattered individuals or groups under a canopy of mature riparian vegetation (e.g., [47,100,128,168]) or in mixed stands of varying canopy height and density (e.g., [100,128]).
Katz and Shafroth [96] present the following table describing density and cover of several established Russian-olive populations in western North America:
River or Location | Density (plants/ha) | Cover (%) | Source |
Rio Grande, NM | 52-357ª | N/A | Freehling 1982 |
Rio Grande, NM | 0-566b | 0-43.3 | Hink and Ohmart 1984 |
Rio Grande, NM | N/A | 11.1-34.8 | [91] |
Chinle Wash, AZ | 430-1150c | 25-78 | [20] |
Duchesne R., UT | N/A | 50 | |
Milliken, CO | N/A | 40 | [103] |
Arikaree R., CO | 0.7-225.2 | N/A | |
S. Fk. Republican R., CO | 4.3-314.3 | N/A | [97] |
Platte R., NE | N/A | 2.2-24.5 | [47] |
Marias R., MT | 20-760 (avg. 186) | N/A | |
Yellowstone R., MT | 20-5,120 (avg. 676) | N/A | [112] |
Snake R., ID | N/A | 80 | [103] |
Snake R., ID | 940 | 81.2 | [25] |
Snake R., ID | 0-55 | N/A | [55] |
a Only individuals >8cm diameter at breast height and >2 m tall sampled
b All individuals sampled
c Estimated from figure
More info for the terms: adventitious, cover, layering, perfect, root crown, top-kill, tree
Russian-olive reproduces by seed and postinjury sprouting.
Breeding system: Flowers are perfect, or some are staminate [46,86,172,198].
Pollination: Fragrant yellow flowers are produced in spring and are insect pollinated [52,96].
Seed production: It is generally stated that Russian-olive produces a large amount of seed, but nothing quantitative was found in the literature. According to Borell [16], the age at which Russian-olive produces its 1st seed crop varies with latitude, but seedlings typically produce fruit about 3 to 5 years after transplanting. Lesica and Miles [112] recorded the ages of fruit-bearing Russian-olive on the Marias and Yellowstone rivers in Montana. None of the Russian-olive trees sampled on the Marias River under age 5 produced fruit, while all trees over age 14 fruited. On the Yellowstone River only 1 of 38 plants ≤ 6 years old fruited in 1998. Fruiting generally began at 7 to10 years of age, and 89% of Russian-olive over 10 years old produced fruit. These results suggest the average age of 1st reproduction for Russian-olive on both rivers is around 10 years [112].
Seed dispersal: Most Russian-olive fruits remain on trees until distributed by animals, especially birds, mostly during the fall and winter. Seed may also be dispersed by water or ice.
Several bird species consume Russian-olive fruit [16,47,138], and at least some are known to defecate viable seed [101]. For example, European starlings are effective dispersers of Russian-olive in southeastern Oregon and may have contributed substantially to its spread there. Kindschy [101] observed large flocks of European starling foraging throughout the winter on Russian-olive fruit in irrigated grass meadows in southeastern Oregon. The starlings then roosted in larger trees such as black cottonwood and Siberian elm, dispersing Russian-olive seed below. When tested, there was no significant loss of viability (P<0.05) in seeds that passed through the digestive tract of starlings [101].
Fruit loosened by wind or feeding birds may also fall to the ground [16] where other vertebrates consume and cache Russian-olive fruit (personal observations cited by [96,113,138]), sometimes up to 500 feet (150 m) from the original sources (F. Johnson personal communication, as cited by [138]). While DiTomaso and Healy [52] indicate that Russian-olive seeds survive ingestion by animals, the only experimental evidence of this is from Kindschy's study [101] of European starlings. Lesica and Miles [113] observed raccoons eating Russian-olive fruits and dispersing seed in their feces, although viability of these seeds was unknown.
Russian-olive seed may also be dispersed by fluvial transport [20,96,113,140]. Lesica and Miles [113] indicate that ripe fruits will float for up to 48 hours. Additionally, observations and evidence presented by Pearce and Smith [140] suggest seed dispersal by water and ice transport, although this was not tested directly and is not documented elsewhere in the literature.
Seed banking: Russian-olive seed stored under "ordinary" conditions remains viable for up to 3 years [136], but seed longevity in the field is undocumented [52]. Russian-olive seeds are dispersed during the late fall and winter in a dormant state and require a period of after-ripening to break dormancy [80,88]. Several researchers have studied Russian-olive seed dormancy (see Germination); however, exact mechanisms of dormancy are unknown.
If seeds retain viability for a long period, Russian-olive may be able to exploit suitable germination conditions over a relatively long time compared to native taxa with which it commonly associates. Success of Russian-olive may be due, in part, to its ability to germinate whenever conditions at a particular site become suitable [156]. More research is needed to determine longevity of Russian-olive seed banks.
Germination: Russian-olive seeds are hard and dormant at maturity and require a period of cool, moist stratification, or possibly scarification, for germination.
Laboratory tests indicate that a period of 2 to 3 months at around 41 °F (5 °C) under moist conditions is required to break Russian-olive seed dormancy [88,176,200]. Dormancy appears to be related to inhibitors found in all parts of Russian-olive seeds [80,88,92]. Activity of the inhibiting substance was not reduced by low temperatures; however, an uncharacterized substance that may reverse inhibition was produced after exposure to low temperatures. Activity of the inhibiting substance was also reversed by gibberellic acid and kinetin [80]. Jinks and Ciccarese [92] found that 6 days of washing before prechilling, or warm, moist stratification for 4 weeks (without prechilling) improved germination, suggesting that the inhibitor is somewhat water-soluble [92].
It has been suggested that scarification may improve germination rates of hard-coated Russian-olive seeds [20,52]. Laboratory tests indicate that dormancy is broken by soaking in sulfuric acid [200], (Heit 1967, as cited by [92]). The dormancy period was reduced in cleaned seed compared to that of dry fruits [136], suggesting that digestion of fruits may also break dormancy.
Some reviews indicate that Russian-olive seeds germinate in many soil types and over a variable period of time, depending on site conditions [52,103], and that Russian-olive seeds germinate under a broader range of conditions than seeds of native willow and cottonwood associates [52]. In greenhouse experiments, Shafroth and others [156] found that Russian-olive seeds germinate under a wide variety of moisture conditions at different times of the growing season, and that seed germination varies under different treatment combinations of light and elevation above groundwater. Russian-olive seedlings suffered little to no mortality following germination [156].
Seedling establishment/growth: Observational and experimental evidence indicates that Russian-olive seedlings can establish on disturbed sites in full sun (e.g. [2,112]), in shade, or within intact groundcover. These nonspecific establishment requirements confer an advantage on Russian-olive over associated native species that require full sun and disturbance for establishment [52,96] (see Successional Status).
Older stands of Russian-olive in Montana generally have plants of many ages, indicating that infrequent disturbance events are not required for recruitment [112]. Katz and others [95] found that seedlings of Russian-olive established within dense, undisturbed herbaceous vegetation on experimental plots, while those of cottonwood did not. Kindschy [101] observed Russian-olive growing throughout irrigated Kentucky bluegrass and orchardgrass pastures in southeastern Oregon. The author suggests that the large seed of Russian-olive contains sufficient food resources to enable sprouting roots to penetrate sod to mineral soil and thus establish in these areas [101].
DiTomaso and Healy [52] indicate that Russian-olive seedlings can survive under a canopy of mature willows and cottonwoods and then grow quickly when the loss of a tree creates an opening in the canopy, although the source of this information is not given. Conversely, willow and cottonwood seedlings seldom survive under a canopy of Russian-olive trees. Shafroth and others [156] found that artificial shade decreased growth of plains cottonwood seedlings more than Russian-olive seedlings in experimental planters but that there was no effect on seedling survival of either species. Russian-olive's ability to establish in the shade may vary with latitude [16,72] (see Site Characteristics).
Russian-olive growth may be independent of many environmental variables. Lesica and Miles [112] measured Russian-olive recruitment and growth rates in 46 stands on the Marias and Yellowstone rivers in Montana. Russian-olive recruitment rate per mature tree in 46 stands varied from 0 to 4.07 recruits/year, with a mean of 0.69 recruits/year. There was no difference in recruitment rate between the Marias and Yellowstone rivers. There was no significant relationship between recruitment rate and tall-tree canopy cover (r²=0.006, P=0.61). There was also no relationship between Russian-olive recruitment rate and associated understory vegetation; nor between recruitment rate and elevation above September river levels for either the Marias or Yellowstone rivers [112].
Growth: Russian-olive is said to have a slow [81] to rapid [16] growth rate. There is little experimental evidence to support these observations; however, growth rate probably varies with site conditions such as temperature, moisture, and light availability, as well as plant age.
In warm areas, Russian-olive seed planted in spring will produce bushy plants 2 to 3 feet (0.6-0.9 m) tall in the 1st season. Under "good" conditions, nursery transplants may reach 4 to 5 feet (1.2-1.5 m) in the 1st year, and 8 to 12 feet (2-4 m) in the 2nd year [16]. Borell [16] suggests that under dry land conditions in the Great Plains, Russian-olive's growth rate is probably half that. Under "prevailing climatic conditions" in the northern Great Plains, planted Russian-olive averaged 12.8 feet (4 m) tall after 10 years with 96% survival, and averaged 16 feet (5 m) tall after 44 years, with 51% survival [72]. On abandoned farm land in Michigan, planted Russian-olive was 17 feet (5 m) tall, with 83% survival after16 to 18 years [77]. Growth rate was negatively associated with height above the September river level for both the Marias (r²=0.20, P=0.028) and Yellowstone (r²=0.18, P=0.012) rivers in Montana. There was no relationship between growth rate of Russian-olive and composition of understory vegetation, although there was a significant negative relationship between Russian-olive growth rate and cottonwood canopy cover (r²=0.06, P=0.002, n=153) [112].
Lesica and Miles [112] found that growth rate (measured by height) of Russian-olive increased with age over all age classes on riparian sites on 2 rivers in Montana. Growth rate varied between 0.1 and 2.7 cm/year with a mean of 0.8 cm/year, and was not different between the 2 rivers when corrected for age. Recruitment and growth were not affected by stand age as reflected by understory vegetation; however, growth, but not recruitment, was greater on lower sites closer to alluvial groundwater [112]. Rankings for biomass production, short- and long-term revegetation potential, and erosion control potential provided by Hansen and others [81] also suggest that Russian-olive's growth rate increases with age. They also suggest that Russian-olive produces a relatively high yield of dry plant material and is relatively persistent.
Asexual regeneration: It has been suggested that Russian-olive spreads by "underground rootstalks" [18]; however, there is no evidence in the literature that indicates that Russian-olive spreads by asexual reproduction under field conditions, except following injury or top-kill. According to Williams and Hanks [200] Russian-olive can establish by layering, and it is propagated by stem and root cuttings and by grafting for horticultural purposes [200]. Brock [20] observed Russian-olive branches that were covered with sediments had numerous adventitious roots on buried stem portions. The occurrence of Russian-olive establishment from stem or root pieces in the field is unclear.
Several workers report that Russian-olive sprouts from the trunk, root crown, and/or roots after top-kill or damage [34,49,52,59,112,140,148,172], and some report sprouting from roots and root crown following fire [35,201]. There is no information in the literature specifically addressing asexual regeneration in Russian-olive after fire.
More info for the term: vines
The currently accepted name for Russian-olive is Elaeagnus angustifolia
L. (Elaeagnaceae) [46,51,74,87,93,94,98,107,161,194,197,198].
According to Vines [191] and Weber and Wittman [197], several varieties of
Russian-olive are known in cultivation, and differ primarily in
leaf size and shape [191].
One variety described in the western literature,
E. a. var. orientalis, is treated as a separate species
by Flora USSR (1949, as cited by [9]). Flora Europaea recognizes no
varieties or hybrids of Russian-olive [178].
More info on this topic.
More info for the terms: geophyte, phanerophyte
RAUNKIAER [146] LIFE FORM:
Phanerophyte
Geophyte
Russian-olive
Russian olive
More info for the terms: alliance, cover, density, fern, forb, forbs, mesic, natural, reclamation, series, shrub, shrubs, stringer, tree, xeric
The following description of habitat types and plant communities in which
Russian-olive occurs is taken from examples found in the literature. The objective
is to provide examples of vegetation types in which it occurs, and is not meant to
imply that Russian-olive is restricted to these types within these areas. Most examples
come from areas where Russian-olive is most widespread and most invasive. In some areas,
particularly the eastern U.S., there is little to no information on vegetation types
in which Russian-olive occurs.
In the northwestern U.S., Russian-olive was introduced primarily for use in
windbreaks and it has established outside of cultivation in several places [87]. In central
Washington, where a sagebrush (Artemisia spp.) steppe site was transformed into a
mitigation wetland, Russian-olive occurs with common cattail (Typha latifolia),
bulrush (Scirpus spp.), common reed (Phragmites australis), and purple
loosestrife (Lythrum salicaria) [89]. At Hanford in south-central Washington,
several species of trees were planted as windbreaks and shade for irrigated farmland.
Some of the more commonly occurring tree species include black locust
(Robinia pseudoacacia), Russian-olive, cottonwood (Populus spp.), mulberry
(Morus spp.), sycamore (Platanus spp.), and poplar (Populus spp.).
Although introduced to this area, these trees now provide habitat for a variety of wildlife,
including nest sites, and hiding and thermal cover. Some species (e.g., cottonwood, poplar,
and Russian-olive) have established along the Columbia River and are considered by some as
"functional components" of these riparian areas [116]. Russian-olive occurred
throughout irrigated Kentucky bluegrass (Poa pratensis) and orchardgrass
(Dactylis glomerata) pastures in southeastern Oregon [101].
Russian-olive occurs throughout California; however, no information was found
describing native plant communities affected by Russian-olive. It occurs primarily in
disturbed, sometimes moist places in the San Joaquin Valley, San Francisco Bay Area,
eastern Sierra Nevada, Modoc Plateau, and parts of the Mojave Desert near springs [49,52,86].
It was used for mine spoil reclamation at a site supporting Jeffrey pine (Pinus jeffreyi),
white fir (Abies concolor), and mountain big sagebrush (Artemisia tridentata ssp.
vaseyana) dominants [31]. Russian-olive is most common in horticultural settings and interior
riparian areas in California [32].
Russian-olive was planted as an ornamental in the Intermountain area, and has
occasionally escaped onto roadsides and along lower elevation streams [46]. On wetland sites
along the Yakima River in south-central Washington, thickets of Russian-olive have replaced
stands of black cottonwood (Populus balsamifera ssp. trichocarpa) and native willows
(Salix spp.) [59]. Hansen and others [81] describe a Russian-olive community type
in Montana. In the Rocky Mountains, foothills, and intermountain valleys, the Russian-olive
community type represents seral stages of many different vegetation types including
ponderosa pine/red-osier dogwood (Pinus ponderosa/Cornus sericea) and Rocky Mountain
Douglas-fir (Pseudotsuga menziesii var. glauca)/red-osier dogwood habitat types.
Isolated stands are found in western Montana, such as near Dillon, Thompson Falls, and in
the Flathead Valley near the National Bison Range [81].
Russian-olive is widespread throughout the Great Basin [127] where it occurs in a
variety of plant communities on a variety of site types. It is common and widespread
throughout most of Nevada, in wet to damp sites of sagebrush deserts [94]. Hall and Hansen
[79] describe an incidental Russian-olive community type that typically forms stringer
communities on upper floodplain terraces adjacent to streams and rivers at the
bottom of deep canyons at low elevations in southern and eastern Idaho. It may also be found
in low depressional areas capable of retaining water near the surface for much of the year,
especially potholes and abandoned river oxbows. Russian-olive stands in Idaho may be associated
with black cottonwood in open communities with widely spaced individuals. The shrub component
may be sparse or robust depending on local site factors, and may include willow, Wood's rose
(Rosa woodsii), hawthorn (Crataegus spp.), and currant (Ribes spp.).
Graminoids, particularly quackgrass (Elymus repens), foxtail barley (Hordeum jubatum),
and Kentucky bluegrass, may dominate the herbaceous understory. The forb component is often poorly
represented and includes bulrush and cattail (Typha spp.) on wet sites, and Rocky Mountain
iris (Iris missouriensis) and Eaton's aster (Symphyotrichum eatonii) on drier sites.
Hall and Hansen [79] report the canopy cover of various native and nonnative plant species recorded
in mid- to late-seral stands of the Russian-olive community type in Idaho. Knopf and Olson [103]
describe a Russian-olive-dominated site along the Snake River where riparian vegetation
is mostly dominated by black cottonwood, willow, and Wood's rose; and upland vegetation is
dominated by big sagebrush (A. tridentata). The Russian-olive site consisted of mature
Russian-olive, about 30 feet (10 m) tall, with canopy cover exceeding 80%. Cheatgrass
(Bromus tectorum) and a few scattered shrubs such as black greasewood
(Sarcobatus vermiculatus) and Wood's rose occurred in canopy openings and in the understory.
A shallow wetland with cattails and bulrushes bordered the north side of the stand [103]. Along the
middle Snake River, from Swan Falls Dam to the Idaho/Oregon border, Russian-olive and tamarisk make
up approximately two-thirds of the tree species present. In this area Russian-olive occurs
primarily with sandbar willow (Salix exigua), peachleaf willow (S. amygdaloides),
and tamarisk in the zone 3 to 5 feet (0.8-1.4 m) above mean river level [55].
Russian-olive has escaped cultivation and established along drainages and in moist meadows
over vast areas of Utah [198]. Christensen [41] describes it as a conspicuous part
of the vegetation in pastures, along fences and ditch banks, and in moist lowlands in the
valleys of central and northern Utah. A riparian site along the Uinta River in northeastern
Utah supported a Russian-olive stand with about 50% canopy cover comprised of individuals
mostly 16 to 20 feet (5-6 m) tall, with several mature trees up to 33 feet (10 m) tall. The
understory was dominated by cheatgrass and forbs, especially mustards (Brassica spp.),
and occasional alfalfa (Medicago sativa) plants. A native riparian site in the
area was dominated by cottonwood associated with willows, scattered Russian-olive and
occasional saltcedar (Tamarix ramosissima and/or T. chinensis). Upland vegetation
in the area was dominated by big sagebrush, green rabbitbrush (Chrysothamnus viscidiflorus),
cheatgrass, Indian ricegrass (Achnatherum hymenoides), and several forbs, especially
desert princesplume (Stanleya pinnata) and lupine (Lupinus spp.) [103]. At Utah Lake,
a comparison of infested and uninfested sites revealed that sites infested with Russian-olive
also supported plant species typical of mesic meadows, especially perennial grasses. A variety
of understory communities was associated with Russian-olive. Plant species consistently associated
with Russian-olive include bearded wheatgrass (Elymus trachycaulus ssp. subsecundus),
redtop (Agrostis gigantea), common ragweed (Ambrosia artemisiifolia), and
tanseyleaf aster (Machaeranthera tanacetifolia) [36]. In the Escalante River Basin in southern
Utah, Russian-olive occurs with tamarisk, Fremont cottonwood (Populus fremontii), and willow [15].
Russian-olive is common throughout the Southwest, especially along rivers on the
Colorado Plateau and other high elevation sites, including the Rio Grande and San Juan
rivers [188]. It is well established and continues to spread in the Four Corners region
[20]. Habitat and plant community information comes primarily from these areas, although
individual or scattered occurrences are also indicated in other areas such as in critical
desert tortoise habitat in the Mojave and Colorado deserts [21].
Dick-Peddie [50] describes a "successional-disturbance riparian" vegetation type
in New Mexico, with 2 series. The Russian-olive series is most common in the northern
part of the state, and the saltcedar series is more common in the southern part [50]. In a
130-mile (210 km) stretch along the Rio Grande River, in north-central New Mexico from Espanola
to Bernardo, Russian-olive occurs within one of the most extensive gallery forests
of Rio Grande cottonwood (Populus deltoides ssp. wislizenii) remaining in the
Southwest, where Rio Grande cottonwood comprises over 93% of the canopy trees, and peachleaf
willow and Goodding willow (Salix gooddingii) comprise the remainder of the canopy trees.
Sandbar willow, Russian-olive, saltcedar, Great Plains false willow (Baccharis salicina),
desert false indigo (Amorpha fruticosa), and New Mexico olive (Forestiera pubescens
var. pubescens) are dominant understory shrubs. Desert grasslands, shrubland, residential
areas, agricultural fields, and levee roads surround the woodland boundaries [91]. Along a more
southerly stretch of the Rio Grande River, between Albuquerque and El Paso, Russian-olive is rare
south of San Antonio, New Mexico. It occurs in communities dominated by cottonwood with Goodding
willow and tamarisk as codominants; and in communities with a dense overstory of cottonwood and a
separate stratum of Russian-olive and Goodding willow, with tamarisk present on adjacent, disturbed
sites. Other plant species in these communities include desert false indigo, yerba mansa
(Anemopsis californica) and sweetclover (Melilotus spp.), with no grasses [33].
Muldavin and others [128] describe a Russian-olive alliance that occurs in lowland regions of
the Rocky Mountains with detailed descriptions of its occurrence in New Mexico. In New Mexico,
the alliance is widely distributed in the middle Rio Grande, Pecos, and San Juan river basins.
Russian-olive stands are often represented by densely forested thickets, often with greater than
90% total canopy cover, and some scattered mature Rio Grande cottonwood in the canopy. The authors
describe 4 provisional community types within the alliance (3 on the Middle Rio Grande, and 1 on
the San Juan River) where Russian-olive is the dominant indicator species, and suggest that additional
information is needed on the composition and ecology of these community types throughout the West.
The Russian-olive/alkali sacaton (Sporobolus airoides) community type is an open-canopied
woodland that often takes on a shrubland appearance due to mowing. Other common native wetland
trees and shrubs in this type include Goodding willow, sandbar willow, and Great Plains false
willow. Herbaceous cover is grassy and dominated by alkali sacaton and occasionally codominated by
saltgrass (Distichlis spicata) and alkali muhly (Muhlenbergia asperifolia).
Smooth horsetail (Equisetum laevigatum) is a common wetland forb in this community.
The Russian-olive/sandbar willow community type has a dense canopy of Russian-olive with sandbar willow
in the understory. Understory herbaceous species are variable, and often dominated by mesic forbs and
grasses. In the Russian-olive/sparse community type, Russian-olive forms nearly impenetrable stands
with scattered sandbar willow and saltcedar in the shrub layer and sparse undergrowth. Herbs are mostly
represented by scattered bunches of grasses that may include purple threeawn (Aristida purpurea),
saltgrass, Baltic rush (Juncus balticus), and alkali sacaton. These stands form as narrow strips
ranging from 30 to 100 feet (10-30 m) wide along lowland riverbanks. Flood control structures such as
jetty jacks are also present and may have influenced the establishment and maintenance of the community.
The Russian-olive/redtop community type and is found on lowland river bars on the San Juan River in
northwestern New Mexico. Shrubs are usually poorly represented in this community type, and may include
sandbar willow or saltcedar. The herbaceous layer is dominated by the nonnative invasive grass redtop,
with a wide variety of other mesic forbs and grasses. Wetland indicators in this type include field horsetail
(Equisetum arvense), reed canarygrass (Phalaris arundinacea), common reed,
common threesquare (Schoenoplectus pungens var. pungens), owlfruit sedge
(Carex stipata), common cattail, and wild mint (Mentha arvensis) [128].
Russian-olive also codominates with Rio Grande cottonwood in several New Mexico riparian
community types. On some sites, where absence of flooding may contribute to Russian-olive
invasion, it forms a sprawling subcanopy under a dense, closed canopy of Rio Grande cottonwood.
In the Rio Grande cottonwood-Russian-olive/New Mexico olive community type, Russian-olive
reproduces under the dense canopy and may be replacing New Mexico olive on some sites. The
Rio Grande cottonwood-Russian-olive/tamarisk community type is widespread in the middle Rio
Grande and San Juan river basins, and is characterized by a mixed-tree canopy with Rio Grande
cottonwood dominating the overstory and Russian-olive in the understory. Saltcedar is well
represented to abundant, and dominates the shrub layer. Overall species diversity is poor in
this community type [128]. Russian-olive also occurs in the subcanopy of the Rio Grande
cottonwood/big sagebrush community type in the San Juan River Basin in northwestern New Mexico
and probably adjacent Utah and Arizona. It may also reproduce and become invasive in the
understory of Rio Grande cottonwood/Goodding willow communities in the Pecos and Rio
Grande basins [128].
Similarly, in a cottonwood/Russian-olive type described by Hink and Ohmart (1984, as cited by [67]),
Russian-olive formed a monotypic understory with herbaceous plants being sparse to absent. In
the northern reaches of the Middle Rio Grande, a cottonwood/juniper (Juniperus spp.) type
was characterized by an understory of juniper mixed with Russian-olive, New Mexico olive, threadleaf
snakeweed (Gutierrezia microcephala), and rubber rabbitbrush (Chrysothamnus nauseosus).
They also recognized a Russian-olive community type dominated by young to intermediate-aged
Russian-olives interspersed among patches of young sandbar willow, cottonwood, saltcedar,
and seepwillow (Baccharis salicifolia) with a dense herbaceous layer of mixed grasses
and forbs (Hink and Ohmart 1984, as cited by [67]). A survey conducted by Mount and others [126]
in 1995 indicates an increase in cover, height, and density of Russian-olive in the Middle Rio Grande
over the 11 years since Hink and Ohmart's study. In the Gila River Valley in southern New Mexico,
Russian-olive occurs both as isolated understory trees within riparian patches composed of Fremont
cottonwood, Goodding willow, Arizona sycamore (Platanus wrightii), boxelder (Acer negundo),
Arizona walnut (Juglans major), velvet ash (Fraxinus velutina), Great Plains
false willow, and Arizona alder (Alnus oblongifolia); and in small monotypic stands on the
periphery of patches [168].
Russian-olive occurs throughout the Great Plains, but is most common in the western
half of the region. Originally planted in shelterbelts, it is one of the hardiest species of trees
introduced to the Great Plains and has persisted and spread in many areas, especially in the
understory along rivers and streams [172,197]. Deserted homesteads in the Great Plains and the
western slope of the Rocky Mountains are often recognizable by persisting windrows of Russian-olive
trees [197].
Hansen and others [81] describe an Russian-olive riparian plant community type as an incidental
type at low elevations on floodplains of the major rivers and streams in central and eastern
Montana. Relatively large stands of this community type are found along the
Yellowstone River and its major tributaries, along the Musselshell River near Roundup, in
irrigated valleys around the Bowdoin National Wildlife Refuge near Malta, along the Milk River
from Glacier National Park to Glasgow, along the Missouri and Sun rivers near Great Falls, and
on the Charles M. Russell National Wildlife Refuge north of Lewistown [81]. About 500 Russian-olive
saplings and seedlings were introduced directly to the Milk River in Montana and Alberta floodplain in
1950. Secondary growth has since formed thickets so dense that other riparian species have been
excluded. Downstream from the point of introduction, Russian-olive and plains cottonwood
(Populus deltoides ssp. monilifera) are scattered on the floodplain and commonly
associated with Wood's rose, peachleaf and sandbar willow, buffaloberry (Shepherdia spp.),
smooth brome (Bromus inermis), and Canada thistle (Cirsium arvense); while silver
sagebrush (Artemisia cana), western wheatgrass (Pascopyrum smithii), and
needle-and-thread grass (Hesperostipa comata) occupy the most elevated and driest sites
on alluvial fans between the floodplain and valley slopes [140].
On many sites Russian-olive forms thickets such that it excludes most other species. Dense stands
of Russian-olive tend to limit access by livestock. However, severe grazing can cause the understory
to be dominated by nonnative herbaceous species such as Kentucky bluegrass and timothy
(Phleum pratense). In stands that are somewhat open, associated species may include widely
scattered plains cottonwood, green ash (F. pennsylvanica), boxelder, peachleaf willow,
narrowleaf cottonwood (Populus angustifolia), and/or an assortment of grasses and
forbs [81]. Adjacent upland or drier sites may be dominated by the silver sagebrush/western wheatgrass
habitat type and a variety of upland species. Wetter sites may be dominated by common cattail, bulrushes,
spikerushes (Eleocharis spp.), or common reed habitat types, or by peachleaf willow
or sandbar willow community types [81,113]. Cottonwood forests may be hundreds of meters wide in
meandering reaches of the rivers [113]. Russian-olive also occurs in riparian plant communities dominated
by green ash, chokecherry, plains cottonwood, red-osier dogwood, western snowberry
(Symphoricarpos occidentalis), and Wood's rose in Montana. In the northern Great Plains,
the Russian-olive community type may represent a seral stage of the green ash/chokecherry
(Prunus virginiana) habitat type or the boxelder/chokecherry habitat type [81].
At the confluence of the Knife and Missouri rivers in north-central North Dakota,
native forest sites are composed of plains cottonwood (73.9% of the density), and peachleaf
willow (24.2%), with 1.9% Russian-olive, which occasionally invades openings within these forests
[42]. At Nature Conservancy preserves in Minnesota, Russian-olive occurs in tallgrass
prairie sites (especially those that are grazed or otherwise disturbed), riparian areas,
and savannas. Here it may affect threatened species such as western prairie fringed orchid
(Platanthera praeclara), grape fern (Botrychium spp.), small white lady's
slipper (Cypripedium candidum), Hill's thistle (Cirsium hillii),
greater prairie-chicken, dakota skipper, and upland sandpiper [148].
Russian-olive cuttings planted on surface-mined reclamation areas in Wyoming had
good survival in plant communities dominated by western wheatgrass, bluebunch wheatgrass
(Pseudoroegneria spicata), needle-and-thread grass, blue grama (Bouteloua
gracilis), Sandberg bluegrass (Poa secunda), big sagebrush, Saskatoon serviceberry
(Amelanchier alnifolia), Gambel oak (Quercus gambelii), quaking aspen
(Populus tremuloides), snowberry (Symphoricarpos spp.), chokecherry, and
mountain brome (Bromus marginatus). Sites with poor Russian-olive survival (0 to 40%)
were dominated by more xeric species, such as bottlebrush squirreltail (Elymus elymoides),
rabbitbrush (Chrysothamnus spp.), basin wildrye (Leymus cinereus), shadscale
(Atriplex confertifolia), Gardner's saltbush (A. gardneri), and winterfat
(Krascheninnikovia lanata) [90].
Russian-olive occurs mostly on low ground along streams or valleys and scattered in agricultural
areas of Colorado, probably originating from cultivated plants [83]. On a study site
northwest of Milliken, Russian-olive occurs in a stand with canopy cover of about 40% and trees
16 to 26 feet (5-8 m) tall. Cheatgrass, Canada thistle, and stinging nettle (Urtica dioica)
dominate the understory, and a few small Siberian elm (Ulmus pumila) are also present. Along
the south side of the Big Thompson River, on a site characterized by an overstory of plains cottonwood
and an understory primarily of grasses, with common cattail, bulrushes, and willows present in small numbers,
scattered Russian-olive occurs infrequently on drier microsites away from the main river channel [103].
Russian-olive is considered a dominant indicator species on the Platte River in Nebraska
[47]. Here its average canopy cover is 12.3% to 24.5% and it typically codominates with plains
cottonwood. In Russian-olive/plains cottonwood vegetation types, important understory species
include common ragweed, sedges (Carex spp.), saltgrass, and Kentucky bluegrass. Plains
cottonwood/Russian-olive vegetation types tend to occur on drier somewhat upland sites, and are
characterized by an overstory of large plains cottonwood and an dense understory of Russian-olive,
green ash, and Missouri River willow (Salix eriocephala). Understory shrubs are
infrequent, but in a few locations roughleaf dogwood (Cornus drummondii) is an important
component. Russian-olive occurs, with an average of 6.2% cover, in plains cottonwood/eastern
redcedar (J. virginiana) communities associated with riverbank grape (Vitis riparia),
Wood's rose, green ash, and desert false indigo with Kentucky bluegrass and poison-ivy
(Toxicodendron radicans) as major herbaceous species. It occurs in cottonwood shrub
communities with 2.2% cover. In some areas along the Platte River, Russian-olive forms dense,
nearly monospecific stands [47].
Along the Arkansas river in western Kansas, Russian-olive occurred with skunkbush
sumac (Rhus trilobata), desert false indigo, and green ash on some sites [73].
There is very little information on Russian-olive's occurrence in the eastern U.S.
Russian-olive is grown as an ornamental in the northeast [16]; however, reports of its occurrence
in natural communities are rare. On Hempstead Plains in Uniondale, New York, Russian-olive occurs
with other woody species such as eastern white pine (Pinus strobus), black cherry
(Prunus serotina), and shining sumac (Rhus copallina) among small pockets of native
plant communities dominated by bluestems (Schizachyrium scoparium, Andropogon virginicus,
and A. gerardii), switchgrass (Panicum virgatum), indiangrass (Sorghastrum nutans),
yellow sedge (Carex pensylvanica), and staggerbush (Lyonia mariana) [131]. In
Virginia, Russian-olive occurs in mesic environments, in sun or part shade, on coastal plain, piedmont,
and mountain sites [192].
In Canada, Russian-olive is often planted as an ornamental in Nova Scotia [150],
and is "frequently planted and fairly hardy" in all but northern parts of Ontario [161],
but there is no information available regarding its distribution in native plant communities.
Russian-olive community types are described in the following publications:
Montana [81]
southern and eastern Idaho [79]
New Mexico [128]