Invasive Autumn Olive: The Unintentional Invader

Autumn Olive, also known as silverberry or elaeagnus umbellata, is a deciduous shrub that originated from Asia. It was first introduced to North America in the 1830s as an ornamental plant and for wildlife habitat improvement. However, this shrub has now become a problem in many areas due to its invasive nature.

What is Invasive Autumn Olive?

Invasive autumn olive is a non-native plant that can grow up to 20 feet tall. It has fragrant, yellow flowers in the spring, and red, juicy berries in the fall, which make it attractive to birds and other wildlife. The shrub grows quickly and can form dense thickets, outcompeting native vegetation by shading and crowding them out.

A dense thicket of autumn olive bushes.

This invasive species has a high tolerance for poor soil conditions and can even grow in disturbed areas like roadsides, abandoned fields, and forest edges. It also has nitrogen-fixing abilities, meaning it can convert atmospheric nitrogen into a form that plants can use, which gives it a competitive edge over other plants.

Why is Invasive Autumn Olive a Problem?

The rapid spread of invasive autumn olive can have negative impacts on both the environment and human activities. Here are some reasons why:

Ecological Impacts

Invasive autumn olive can alter ecosystems by reducing biodiversity and disrupting natural processes. It outcompetes native plants for resources like light, water, and nutrients, which can lead to a decline in native plant populations. This, in turn, can affect the food and shelter availability for insects, birds, and other wildlife that rely on native plants.

Invasive autumn olive's red berries are attractive to birds, aiding in its spread.

Invasive autumn olive can also alter the soil chemistry by fixing nitrogen, which can lead to imbalances in soil nutrients that favor non-native plants over natives.

Social and Economic Impacts

Invasive autumn olive can also have economic impacts on agriculture and forestry by decreasing the productivity of crops and timber. It can also hinder recreational activities like hiking, hunting, and birdwatching by forming dense thickets that are difficult to navigate.

How Can We Control Invasive Autumn Olive?

Controlling invasive autumn olive requires a combination of different methods, including mechanical, chemical, and cultural techniques. However, it is essential to note that each method has its advantages and disadvantages and may vary depending on the site and severity of the invasion.

Mechanical Control

Mechanical control involves physically removing the plant using tools like chainsaws, loppers, or hand-pulling. This method is effective for small infestations or single plants but may not be practical for larger areas due to the time and effort required. Mechanical control can also cause soil disturbance, which can aid in the germination of additional seeds.

Removing invasive autumn olive with a chainsaw.

Chemical Control

Chemical control involves applying herbicides to the plant or the surrounding soil. This method is effective for large areas or severe infestations, but it requires caution to ensure the safety of non-target plants and animals. Herbicides should only be applied by trained professionals and according to label instructions.

Applying herbicide to invasive autumn olive.

Cultural Control

Cultural control involves altering the site conditions to favor native plants and discourage invasive ones. This method includes practices like prescribed burning, grazing, or planting native species. Cultural control can be a long-term solution, but it may require multiple treatments and may not be suitable for all sites.

Invasive autumn olive is a prime example of how unintended consequences can arise from introducing non-native species to new habitats. Its impact on native ecosystems and human activities highlights the importance of early detection and rapid response to prevent further spread. The control methods discussed above can help mitigate the damage caused by invasive autumn olive, but they must be carefully implemented to prevent unintended harm to the environment or people.

Non-Native Species, Biodiversity Loss, Ecosystem Disturbance, Nitrogen Fixing, Control Techniques