Skaneateles Conservation Area/Invasive species/Elaeagnus umbellata

<< Prohibited invasive plants at the SCA

Elaeagnus umbellata (autumn olive)
Autumn olive (Elaeagnus umbellata) is native to China and Japan. It has become much more apparent at the Skaneateles Conservation Area (SCA) in recent years. Autumn olive can grow up to 20 feet high and form a dense layer. Its leaves have a silvery underside that easily differentiate it from similar native shrubs.

Invasiveness ranking for Elaeagnus umbellata (autumn olive)
Autumn olive (') is listed as a very highly''' invasive shrub in New York State with a relative maximum score of 94%.

Autumn olive is also prohibited by New York State law.

1. Ecological impact (40/40)
1.1. Major, possibly irreversible, alteration or disruption of ecosystem processes (10/10)


 * Autumn olive has been shown to affect soil microbial communities even when it is present in relatively low densities.


 * It has root nodules that fix atmospheric nitrogen, resulting in its potential to degrade native plant communities adapted to low nutrient levels.

1.2. Major alteration of natural community structure (10/10)


 * Increases shrub layer and eradicates all layers below.

1.3. Major alteration of natural community composition (10/10)


 * Completely alters the shrub layer and layers below.

1.4. Severe impact on other species or species groups (10/10)


 * Changes the abundance and composition of native plants.


 * Produces leaves in early spring, prior to most native plants.

2. Biological characteristics and dispersal ability (25/25)
2.1. Abundant reproduction with more than 100 viable seeds per plant (4/4)


 * Mature autumn olive shrubs can produce about 30 pounds of fruit annually, which is equivalent to about 3 pounds of seeds or about 66,000 seeds.


 * Under favorable conditions, autumn-olive can produce fruit by 3 to 5 years of age, usually at about 4 to 8 feet in height.


 * Fruit production is reduced by shading.

2.2. Numerous opportunities for long-distance dispersal (4/4)


 * Dispersed mainly by birds and small animals.


 * Dispersal can be more than 100 meters.

2.3. High potential to be spread by human activities (3/3)


 * Until 2015, autumn olive was still legally sold and planted in New York.

2.4. Two or more characteristics that increase competitive advantage (6/6)


 * Perennial habit.
 * Fast growth.
 * Some shade tolerance.
 * Can grow well on a variety of soils, including sandy, loamy, and somewhat clayey textures with a pH range of 4.8 to 6.5.
 * Excellent tolerance to drought..

2.5. Forms a dense layer above shorter vegetation (2/2)


 * Forms large stands.

2.6. Can germinate/regenerate in existing vegetation in a wide range of conditions (3/3)


 * No special conditions are needed for the germination.
 * Widely adapted.

2.7. Other species in the genus invasive in New York or elsewhere (3/3)


 * Russian olive (Elaeagnus angustifolia) is listed as invasive in New York State
 * Russian olive has not been reported in the direct vicinity of SCA and seems fairly rare in Central New York in general.
 * A population of Russian olives has been observed near Skytop (Syracuse University).

3. Ecological amplitude and distribution (21/25)
3.1. Large dense stands present in areas with numerous invasive species already present or disturbed landscapes (2/4)


 * Large density stands have been observed and documented with other non native plants.

The similar Russian olive (Elaeagnus angustifolia) is not currently present in this area and is generally considered less invasive in New York State.

Autumn olive and Russian olive are very similar in appearance but Russian olive has green, mealy fruit, in contrast to the bright, mottled red fruit of autumn olive. The two species are ecologically similar and require the same control treatment.

4. Difficulty of control (8/10)
Apparent signs of rabbits chewing the bark at the base of these shrubs is often present, but this seems to have little effect of the health of these hardy, drought tolerant shrubs.

Plants cut down at ground level regrow quickly from basal branches at ground level and root shoots.