The Oriental Bittersweet plant is known as Celastrus orbiculatus. According to the DNR, the oriental bittersweet plant is already established throughout Michigan. Celastrus Orbiculatus was brought to the states from Japan, China, Korea and other parts of Asia in the late 1800s.
Their proliferation in Michigan is due to the dispersal of seeds by birds and pollinators. The invasive species produces vines, which seem detrimental to native plants. The plant produces short vines but with the presence of other vegetation the vine grows around the tree or plant limiting its access to outside resources and interactions. These vines grow vigorously and tend to suffocate native plants from growing, by preventing exposure to sunlight and other resources in the landscape.
Though it is an invasive, this species is sometimes marketed for landscape and decoration purposes. This is also a problem which is allowing the oriental bittersweet to reproduce and survive in the environment. Oriental bittersweet is often mistaken for native bittersweet species. By expanding their dominance in the environment, they are competing with the native American Bittersweet species. Some ways to differentiate the two species include oriental bittersweet having berries along the vine, while the native bittersweet only has berries at the tip of the vine. Oriental bittersweet has thorns on the stem, while the native bittersweet has a smoother surface on the stem.
This invasive is spreading because of its success in hybridization with other plants, which is allowing it to increase its offspring and fitness levels. If the native species is overtaken by the oriental bittersweet, many ecological services will be affected. It would most likely affect the species of pollinators which usually visits the native area. It would also cause some changes in the trophic cascades of Michigan’s environments. Native bittersweet plants are the primary producers which transfer energy to consumers above in the food chain.
A rising trend of oriental bittersweet population densities, means that native organisms will be forced to change their regular diets. Presence of this species will encourage organisms to emigrate to other landscapes for food resources or shelter. Birds, insects and small mammals feed on the native bittersweet, but an exponential increase in these invasive trends can be a cause of biodiversity loss.
Native bittersweet is under attack, and becoming a rare plant on the eastern coast of the United States. Becoming aware of some key distinctions between the two species, will help to contain the invasive species from proliferating at dangerously fast rates. With knowledge about the native and invasive bittersweet, Michigan can help native species dominate in its respective niches; instead of allowing the oriental bittersweet to thrive and kill everything in its way!
This article is part of the ongoing series on invasive species funded in part with funds from the Michigan Invasive Species Grant Program through the Departments of Natural Resources, Environmental Quality, and Agriculture and Rural Development