BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Elaeagnus angustifolia | Russian-Olive 



GENERAL BOTANICAL CHARACTERISTICS : 
Russian-olive is an introduced, deciduous, shrub or small tree usually
12 to 45 feet (4-14 m) tall [2,7,12,28,30].  It can grow up to 6 feet
(1.8 m) per year [31].  It forms a dense, rounded crown [28].  Near the
ground its branches spread from 10 to 20 feet (3-6 m).  Unpruned trees
have five or six main stems starting near the ground [2].  The twigs are
flexible, coated with a gray, scaly pubescence and often have a short
thorn at the end [12,28].  The leaves are 1.7 to 3.5 inches (4.5-9 cm)
long and are covered with scalelike stellate pubescence [12,28,30].  The
bark is thin with shallow fissures, and exfoliates into long strips
[28].  It has a deep taproot and well-developed lateral root system [2].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Sexual Reproduction:  The average seed-bearing age of this species is 3
to 5 years [17].  The seeds are ingested with the fruit by birds and
small mammals and dispersed in their droppings.  The outer layer of the
seed is impermeable to digestive juices.  The seeds can remain viable
for up to 3 years and are capable of germinating over a broad range of
soil types [17].  Germination is enhanced by stratification in moist
sand for 90 days at 41 degrees Fahrenheit (5 deg C) [30].  Spring
moisture and slightly alkaline soil tend to favor seedling growth [23].

Vegetative reproduction:  Russian olive-sprouts from the root crown and
sends up root suckers [3,32].


SITE CHARACTERISTICS : 
Russian-olive naturalization is rapidly increasing, especially in
riparian zones [24].  It is commonly found growing along floodplains,
riverbanks, stream courses, marshes, and irrigation ditches in the West.
It is well established throughout the Platte River Drainage of Colorado
and Nebraska [24,25].

Salt-tolerance:  Russian-olive is tolerant of considerable amounts of
salinity or alkalinity [24,30].  However, it prefers sites with low to
moderate concentrations (100-3,500 p/m) of soluble salts.  The lower pH
limit of Russian-olive is 6 [24].

Soil and moisture:  Russian-olive thrives under a wide range of soil
textures from sand to heavy clay, and can withstand flooding and
silting.  It grows best in deep sandy or loamy soils with only slight
salt and alkali content.  There are dense, healthy stands in
riverbottoms where the water table is seldom more than 2 feet (0.6 m)
below the surface.  In contrast, it survives considerable drought [2].

Climate and elevation:  Russian-olive can withstand temperatures ranging
from -50 degrees Fahrenheit (-45 deg C) to 115 degrees Fahrenheit (46
deg C).  It occurs from sea level to at least 8,000 feet (2,438 m) [2].
Elevational range for several western states is as follows [6]:
 
        Utah: 4,500 to 4,600 feet (1,372-1,402 m)
        Colorado: 4,500 to 7,000 feet (1,372-2,134 m)
        Wyoming: 3,900 to 6,200 feet (1,189-1,890 m)

Shade tolerance:  Russian-olive is somewhat shade tolerant and can
withstand competition from other shrubs and trees [2,16].


SUCCESSIONAL STATUS : 
Russian-olive occurs as a initial colonizer of disturbed floodplains and
streambanks.  It is relatively shade tolerant and once established can
persist throughout seral stages and become the climax dominant
[2,16,25].  This species has displaced cottonwood in many major
drainages [25].  Russian-olive community types in central and eastern
Montana seem to represent a seral stage of the green ash/common
chokecherry (Prunus virginiana) habitat types or the boxelder/common
chokecherry [14].


SEASONAL DEVELOPMENT : 
Russian-olive generally flowers from May through June [24,28,30].  The
fruits mature from August to October and remain on the tree throughout
the winter or until the crop is consumed [2,23].

Related categories for Species: Elaeagnus angustifolia | Russian-Olive