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Problematic Plant Monitoring in Wilson's Creek National Battlefield

Three people using backpack herbicide sprayers in a field
Problematic plant treatment at Wilson's Creek National Battlefield.

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What Are Problematic Plants?

Sometimes plants grow in places where they don't naturally occur and some plants can cause damage to ecosystems and even harm people. Exotic plants are nonnative species that are typically introduced into an ecosystem by human actions, whether intentional or not. Invasive plants are exotic species that cause ecological or economic harm. Pest plants, which can be native species, interfere with specific management objectives and are sometimes called weeds. We refer to the collection of exotic, invasive, and pest plants as problematic plants.

Problematic Plant Management

National parks spend a lot of time trying to remove or control problematic plants to protect native plant and animal communities and visitors at parks. When a plant species is impairing park resources, managers are required to control the plant. They use five criteria to decide what other problematic plants they will control: the origin of the species, prudence of the action, feasibility of controlling the plant, the harm or impact that the plant causes, and the harm that removal of the plant could cause. Environmental assessments, the professional judgment of experts, and scientific research provide the information managers need to make these decisions. Parks also consult with regulating agencies and the public.

Map of 157 transect lines distributed at equal intervals across the park
Transects used to monitor problematic plants in Wilson's Creek National Battlefield.

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Plant Surveys

Park managers need to know where problematic plants are to control them. The Heartland Inventory and Monitoring Network collects information on the cover (a measure of how much ground is covered by the plant), distribution, and location of problematic plants at Wilson's Creek National Battlefield. We surveyed the park in 2006, 2013, 2016, and 2020. Managers can develop management actions and track the success of their control efforts using the information from our surveys. We use an early detection watch list and a park-established watch list to search for problematic plants. Early detection species are plants that have not been detected on the park before but have the potential to grow there. Plants on the park-established watch list have been found in the park during previous surveys.

Problematic Plants at the Park

Since 2006, we have identified 53 problematic plants at Wilson's Creek National Battlefield; 40 of these species were present in 2020. Thirteen plant species exceeded the 10-acre threshold we use as an indicator of whether a plant species will be easy or difficult to control: smooth brome, smooth sumac, Kentucky bluegrass, wintercreeper, winged sumac, tall fescue, Queen Anne's lace, Osage orange, sericea lespedeza, Japanese honeysuckle, bald brome, eastern redcedar, and multiflora rose. Because of the number, extent, and cover of problematic plants and the small size of the park, control efforts should focus on treating high priority species across the entire park. These can include species capable of rapid spread, species with low population levels, and species that can be effectively controlled.

Survey Highlights

  • Park surveys in 2020 show that Poverty brome, Japanese hedgeparsley, and common periwinkle have all decreased and European privet and Johnsongrass have increased.
  • Osage orange, sericea lespedeza, Japanese honeysuckle, bald brome, eastern redcedar, and multiflora rose are well-established in the park; they were found in over half of all the areas searched in 2020.
  • Silk tree, white mulberry, tree-of-heaven, and Chinese yam were found at low levels in 2020, this may make them good candidates for complete removal from the park.


Dark green leaves on vines
Chinese yam vine

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Species Spotlight: Chinese Yam

Chinese yam (Dioscorea opositifolia), also known as cinnamon vine or air potato, is a vine that was introduced to the U.S. from China in the 1800s for food and medicine and for ornamental purposes. In the U.S., the vine does not produce seeds. Male and female flowers grow on separate plants and no female plants have been found in the wild here. Instead, this vine spreads through sprouting of the small bulbils growing on the vines that look like little potatoes. Even small pieces of these bulbils will sprout into a new plant similar to how cut up potato pieces sprout. This yam is a very aggressive vine that can take over large areas, smothering trees, shrubs, and smaller plants. It has very heavy vines and can break the limbs of large trees. Chinese yam continues to be sold as an ornamental garden plant, but it should be discouraged because it can easily escape a garden. This species is growing at Wilson's Creek National Battlefield, but in low enough levels that it could potentially be removed from the park.

For More Information

Read the Full Report.

Check back later for updates. We will update this page each year as we gather information.

Visit the Heartland Inventory & Monitoring Network website.

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Wilson's Creek National Battlefield

Last updated: June 22, 2022