Non-Native Invasive Species

NNIS have significantly impacted United States ecosystems and cost millions of dollars to prevent. Whether it is an insect, plant, weed, aquatic or terrestrial - NNIS can have a huge impact on the ecosystem they invade.

What happens when a NNIS is introduced to an ecosystem? picture of the hemlock woolly adelgid

Non-native invasive species (NNIS) seriously alter the landscape and disrupt critical ecosystem functions. The result can be loss and destruction of forage and/or habitat for wildlife/fish/plants, loss of available grazing land, diminished land values, lost forest productivity, reduced groundwater levels, soil degradation, increased risk of devastating wildfires, and diminished recreational enjoyment. Entire ecosystems and communities are experiencing the detrimental impact of NNIS.

Pests such as emerald ash borer, hemlock wooley adelgid and gypsy moth have long reaching consequences for plant and tree species across the country, killing off ash, hemlock and other tree species. Infestations of non-native invasive insects can cause millions of trees to die. Non-native invasive wildlife can take over or destroy habitat for native wildlife species. Impacts to native wildlife species can then impact the forest ecosystem as natural balances are destroyed. Aquatic invaders can outcompete native and local fish populations or destroy their food source.

There are numerous research studies attempting to understand and control these pests. At present, though, it is a race against time. Will controls be found before the landscape is irreparably altered? We don't know. What we all can do, however, is to heed the warnings against moving wood. The natural progression of insects is relatively slow as long as we don't give them a ride. This is the reason for the ban on moving firewood.

How to Prevent Spreading Invasive Species

Stopping the spread of an invasive species depends on if it is plant, terrestrial animal, aquatic or weed.

What can you do to help? Do not bring firewood from home to the Mark Twain National Forest. Do not unwittingly spread the emerald ash borer, sirex wood wasp, hemlock woolly adelgid or other firewood borne invasive species. Firewood is available at or near camping facilities.

  • Aquatics

    View of the Stone Mill Creek during spring
    • Clean your boats, waders and any other equipment before leaving an area where you've been fishing/recreating. 
    • Eliminate any water before you transport your boat, canoe, kayak or tube.
    • Clean and dry anything that came in contact with the water before you leave - including equipment, pets and even yourself. 
    • Don't put plants or wildlife into the water unless they came from that water. 
  • Terrestrial/Insect/Plant

    A placeholder image
    • Make sure your belongings and pets are free of mud and plant debris before you leave.
    • Use local firewood for campfires - firewood can be collected from National Forests System lands near where you are camping free of charge.
    • Use certified weed free hay when traveling with livestock.
    • Identify a cleaning station near your destination, visit it before you leave.
    • Use the boot cleaner located at most trail heads when entering and leaving a hiking trail. 


Be On the Lookout!

Click on a heading below to find out more about Non-Native Invasive Species that impact the Mark Twain:









For More Information:

Federal Resources:

  • USDA Forest Service Region 9 Non-Native Invasive Species (NNIS) (HTML
  • Invasive Species Information from the USDA ( HTML
  • Animal and Plant Health Inspection Service (APHIS)(HTML
  • State and Private Forestry (USDA - FS) - Forest Health Protection HTML
  • Northeastern Area Forest Health Protection HTML
  • US Forest Service - Research and Development HTML
  • US Fish and Wildlife ServiceHTML

State Resources

  • EddMaps HTML
  • Missouri Department of Conservation HTML
  • Missouri Invasive Species Plant Task Force HTML
  • Missouri Invasive Species Plant Task Force Invasive Plant Assessment HTML
  • North American Invasive Species Network HTML


  • NatureServe HTML
  • Protect Your Waters HTML
  • National Wildlife Federation HTML
  • The Nature Conservancy HTML
  • North American Invasive Species Network HTML
  • Center for Invasive Species and Ecosystem Health html

For a more complete list of organizations and federal agencies who are working to protect native species visit Invasive Species Info

Invasive plants:

  • Federal Interagency Committee for the Management of Noxious and Exotic Weeds HTML
  • Plant Conservation Alliances HTML
  • USDA APHIS Noxious Weeds Program HTML
  • Forest Service Rangeland Ecology - Invasive HTML


What are the different types of problem species and how are they defined?