Ecological profile: Autumn Olive (Elaeagnus umbellata)
Figure 1: Autumn olive
- Introduction to Elaeagnus umbellata
- Present Locations in Canada
- Dispersal Methods and Biology
- Ecological Impacts
- Methods of Control
Autumn Olive grows to a height of 20 feet and is distinguished by the presence of silver pubescens on the underside of its simple lobed leaves. The leaves grow densely together and grow to a diameter of approximately 1.5cm. The large, teardrop shaped buds are a marbled colour with alternate arrangement.
Native Range and Vector
Autumn Olive is deciduous shrub native to China, Korea, and Japan. It was imported to North America starting in the 1800s and became highly popular as an erosion control plant in the 1950s due to its fast growth, relatively short height, and attractive appearance. Autumn Olive grows to a height of 20 feet and is distinguished by the presence of silver pubescens on the underside of its simple leaves. The large, teardrop shaped buds are a marbled colour with alternate arrangement.
Aside from a need for direct sunlight Autumn Olive is an adaptable shrub that can survive in a wide variety of soil types. In comparison to native plants it has no sensitivity to moisture, soil pH, or pollution. Autumn Olive does produce nitrates in the soil, and thus is resistant to nitrates. Autumn Olive may prefer a warmer climate as it is not particularly common In Canada outside of southern Ontario and struggles to grow in habitable zone 3 but this could also be attributed to municipal planting practices and requires more research.
Autumn Olive primarily reproduces by producing (depending on specimen size) several dozen to several thousand small (1-2cm diameter) fruiting bodies holding seeds. The Fruits are bright red with silver speckles. These seeds are edible to numerous species of mammals and birds., which creates many potential vectors for spreading the seeds. Birds can spread the seeds many kilometers from the parent plant, creating a wide distribution. Because Autumn Olive is capable of fixing Nitrogen in the soil it can grow in infertile soils. Autumn Olive can also regenerate from broken branches, meaning that pruning this species can result in several saplings springing up underneath the parent tree if the cuttings are not removed. Since this species grows at a fast rate (reaches adult size in 2-3 years) a missed branch or discarded pile of cut branches can quickly become reproducing specimens. To improve offspring growth and reduce competition Autumn Olive releases chemicals into the surrounding soil thus altering the soil chemistry making it difficult for other plant species to survive. As a plant very few of the seeds will grow to adulthood compared to the number of seeds produced, but a fast growth rate means that the species quickly outgrow most potential dangers and as mature specimens have very few natural threats. The overall reproduction profile is most consistant with r strategists as the plant grows to a modest size for a woody plant (20ft), produces thousands of offspring, of which few survive t(Ministry of natural Resources, 2006
Special consideration:care must be taken when removing specimens, as broken branches can regrow into new trees if left where they fell in suitable habitat. Berries can be used to make jam.
Figure 2: Distribution of Autumn Olive in Ontario (Catling et al. 1997)
Figure 3: Global distribution of Elaegnus Umbellata, Taken from Wikicommons.com
Nature Concervancy of Canada, Author Unknown, Autumn olive. (n.d). Retrieved January 25, 2017, from http://www.natureconservancy.ca/en/what-we-do/resource-centre/invasive-species/autumn-olive.html?referrer=https%3A%2F%2Fwww.google.ca%2F
Ministry of Natural Reources, Author unknown, Autumn Olive. (2012, February). Retrieved January 22, 2017, from https://mnfi.anr.msu.edu/invasive-species/AutumnOliveBCP.pdf
Michigan State University, Author unknown, Autumn olive: one invasive shrub. (n.d.). Retrieved January 25, 2017, from http://msue.anr.msu.edu/news/autumn_olive_one_invasive_shrub
Catling, P., Oldham, M., Sutherland, D., Brownell, V., & Larson, B. (1997). The Recent Spread of Autumn Olive, Elaegnus umbellata, into Southern Ontario and its Status. Retrieved January 25, 2017. (Figure 2)
Wisconsin Department of Natural Resources http://dnr.wi.gov/topic/Invasives/fact/images/AutumnOlive4.jpg (Figure 1)