|
E1,01911lis angustifvlia L. -
<br /> itussia '1-Olive
<br /> r � �
<br /> Family:Elaeagnactae
<br /> Mange: 1-hroughout the western U.S.and in most other states,
<br /> with the exi-eption of the southeastern U.S.
<br /> Habitat:Riparian areas,floodplains,grasslands,roadsides,
<br /> fcncero%,vS seasAmally moist pastures,ditches,and ether
<br /> disturbed sittN+.Often inhabits seasonally moist areas and sites
<br /> near farmlands.(.;rtsws under a wide range of environmental
<br /> conditions, including;clay,sandy,and fairly alkahm-or saline
<br /> soils.crows best in inland areas with warm summers and cold
<br /> winters.T'oterates drought,high water tables,and bath freezing and hot temperatures.
<br /> Origin:Native to the temperate regions of Asia.Continues to be cultivated as a hardy landscape ornamental and
<br /> tvintibreak tree,but has escaped cultivation in many areas of the United States.
<br /> Impacts: ilussian-olive is especially invasive in seasonally wet riparian areas and may eventually replace stand-.,-
<br /> of native i,illow-,(Salix spp.)and cottonwoods(Populu4 spp.)at some locations.Although Russian-olive fruits
<br /> prux ide food for wildlife, trtvs are used to a 1.—,qer degree than the native vegetation.
<br /> ' Western states listed as Noxious Weed:Colorado,New Mexico
<br /> t California Invasive Plant Council (Cal-IPC) Inventory: Moderate Invasiveness
<br /> Russian-olive is a fast-growing,deciduous tree to 25 R tall,with silvery foliage.Its twigs and branches are
<br /> g-
<br /> sometimes thorny.Leaves are alternate,simple,narrowly lanceolate or elliptic,mostly 2 to 4 inches long,with
<br /> snetwth margins.The upper surface of the leaf is gray-green and moderately covered with silvery star-shaped
<br /> hairs and scales.The twigs,leaf stalks,and lower leaf surfaces are silvery gray,and densely covered with silvery
<br /> shield-shaped (peltate)scales.Cut trees ti pically resprout from the crown and roots.Depending on the location,
<br /> roots sometimes associate with nitrogen-fixing bacteria(Frankia).
<br /> u Russian-olive flowers are in umbel-like clusters.The flowers are highly fragrant,mostly 5 to 10 mm long;and
<br /> wide,consisting of a narrow,bell-shaped calyx(sepals as a unit)with four acute petal-like lobes.The fruits are
<br /> drupe-like(with a fleshy outer layer covering 1 seed),ovoid,about 0.5 to I inch long and covered with silvery
<br /> scales.Plants primarily coproduce by seed.Most fruits remain on trees until distributed by animals,especially
<br /> birds.The seeds survive ingestion by animals.Seeds are dormant at maturity and rquire a cool moist
<br /> f, stratification period of about 2 to 3 months.,one seeds are hard-coated and may require scarification as well as
<br /> r ratification.Stored seeds survive up to 3 years,but longevity in the field is undocumented.
<br /> NON-CHEMICAL CONTROL
<br /> 'Mechanical Manually removing seedlings and saplings with roots before they mature is a more effective than removing
<br /> (pulling cutting, mature trees.Pulling or digging out larger plants is both extremely labor-intensive and not recommended,
<br /> i ;'disking) since it can leave behind root fragments that can resprout Ring-barking has also been used to kill older trees.
<br /> Russian-olive plants with small diameters of 3.5 inches or less can be pulled out with a weed wrench when
<br /> soils are moist.In certain situations larger trees can be removed using a bulldozer or a tractor with an
<br /> attached chain.Any remaining exposed roots should be cut off below ground level and buried.
<br /> i Girdling and cutting can suppress Russian-olive but are not effective control options when used alone.Trees
<br /> vigorously resprout from the roots and crown,or below the girdled or cut area,or along root lines,often
<br /> j resulting in even denser growth.These techniques also require frequent retreatment and cause significant
<br /> j soil disturbance.Cutting trees in mid-summer and then mowing the resprouts once in late summer the
<br /> following year gave effective control,but was labor intensive and costly.
<br /> Cutting trees before fruits mature can be combined with either burning the stumps or applying an herbicide
<br /> in a cut stump treatment to give effective control.
<br /> Choosing other landscape ornamentals for sites where seedlings may invade nearby natural areas can help
<br /> prevent the spread of Russian-ollve.
<br /> Cultural Small seedlings of Russian-olive may be susceptible to fire,but burning alone does not adequately control
<br /> larger individual plants as they vigorously resprout following fire.Stump burning of Russian-olive has been
<br /> Weed Control in Natural Areas in the Western United States 169
<br />
|