Invasive Plants

Noxious weeds are non-native, invasive plants. At first glance they may appear pretty, but invasive plants can pose serious environmental threats.

What is an Invasive Plant Species?

An "invasive species" is defined as a species that is

  1. Non-native (or alien) to the ecosystem under consideration; and,
  2. Whose introduction causes or is likely to cause economic or environmental harm or harm to human health. (Executive Order 13112).

Why are invasive plants successful?

Dalmation Toadflax with inset a snapdragon. The pretty flower is easily mistaken for a snapdragon. Beautiful but dangerous!
  • Many invasive plant species produce large quantities of seed.
  • Many invasives thrive on disturbed soil.
  • Invasive plant seeds are often distributed by birds, wind, or unknowingly humans allowing seed to moving great distances.
  • Some invasives have aggressive root systems that spread long distances from a single plant.
  • These root systems often grow so densely that they smother the root systems of surrounding vegetation.
  • Some plant species produce chemicals in their leaves or root systems which inhibit the growth of other plants around them.

What are the impacts of invasive plant species?

  • Invasive species have contributed to the decline of 42% of U.S. endangered and threatened species, and for 18% of U.S. endangered or threatened species, invasives are the main cause of their decline.
  • Invasive species compete directly with native species for moisture, sunlight, nutrients, and space.
  • Overall plant diversity can be decreased
  • Establishment and spread of invasive species can degrade wildlife habitat
  • Results in poor quality agriculture lands
  • Degraded water quality
  • Increased soil erosion
  • Decreased recreation opportunities

These impacts change nature's balance on which all species depend.


You can help!

Wanted Dead - Purple Loosestrife poster.

Here are a few things that you can do to fight invasive plants and preserve the plant species native to your region:

  • Don't pick the flowers of noxious weeds and take them home.
  • Drive only on established roads and trails away from weed infested areas.
  • When using pack animals, carry only feed that is certified weed free.
  • Remove weed seeds from pack animals.
  • Don't pick and transport wild flowers that you can't identify.
  • Do not camp or drive in weed infested areas.

The Chief of the USDA Forest Service has identified invasive species as one of the four critical threats to our Nation’s Forests and Grasslands. The USDA Forest Service has designed an invasive species program whose goal is to reduce, minimize, or eliminate the potential impact of invasive species across all landscapes and ownerships.

Forest Service National Strategic Framework for Invasive Species Management

Forest Service National Strategic Framework for Invasive Species Management cover.

The Forest Service National Strategic Framework for Invasive Species Management responds to a 2010 USDA Office of Inspector General audit of Forest Service invasive programs by providing a consistent, agency-wide approach to the prevention, detection, and control of invasive insects, pathogens, plants, wildlife, and fish.

Read more about the Framework for Invasive Species Management…

Non-Native Invasive Species Program Accomplishments




Eastern Region


Eastern Region

Pacific Northwest Region

Southern Region

Non-Native Invasive Species: Eastern Region Program Accomplishments 2011

Non-Native Invasive Species: Eastern Region Program Accomplishments 2011 cover page.

The Eastern Region of the Forest Service Non-native Invasive Species Program is guided by the Forest Service's Non-native Invasive Species Framework (PDF, 326 KB). The Eastern Region's accomplishments for 2011 are summarized in Non-Native Invasive Species: Eastern Region Program Accomplishments 2011 (PDF, 12.2 MB).

Non-native Invasive Species Learning Kit

Non-Native Invasive Species Learning Kit logo.

Developed by the Forest Service's Eastern Region, Interactive Non-native Invasive Species learning kits are available to educate preschool to adult groups about non-native invasive plants and animals.

For More Information

To learn more about this program and invasive species please visit the following websites:

Aquatic Invasives in the Great Lakes Region
Hiawatha National Forest, Michigan

Thumbnail of interpretive panel.

Aquatic invasive species in the Great Lakes Region include both plants and animals, which are mostly spread through human activities such as boating and fishing. Once introduced to bodies of water these species proliferate, disrupting the food chain and damaging native fish populations.

Download panel (PDF, 1.6 MB)…