Invasive Species Information and FAQ

What is an Invasive Species?

An invasive species is a plant, fungus, or animal species, not native to a specific location (an introduced species), and with the ability to spread to such a degree that damage is caused to the environment, human economy and/or human health.

 

What makes a Species Invasive?

    Common traits of invasive species include:

  • Fast growth
  • Rapid reproduction
  • High dispersal ability
  • Ability to alter their growth form to suit current conditions (phenotypic plasticity)
  • Tolerance of a wide range of environmental conditions (ecological competence).

 

Can a Native Species be Invasive?

Species native to a certain environment have to compete for food and shelter, and predators keep their populations in check so native species do not become invasive. But when those elements are absent, a native species can adapt qualities of invasive species, such as an excessive ability to reproduce and aggressive tendencies. Native species do not usually move to a completely different habitat so their tendency to stay in their original habitat makes them manageable.

 

Are all Non-native Species considered Invasive?

No, not all non-native species are invasive. In these cases, the non-native species has not yet adapted to the new area that it finds itself. Foe example: an Indian tiger introduced to Iceland would not survive! In other cases, however, a new species may do well, very quickly, in its new habitat. For example: a striped bass introduced to the Sacramento River in California. Current research states that up to 20% of non-native species introduced into the U.S. become be invasive (U.S. Congress, Office of Technology Assessment, 1993).

 

How can invasive species be controlled?

There may be time to eradicate an invasive species when first introduced into a new area if it is detected in time.  

If eradication is not possible, then control and management efforts include:

  • Physical or Mechanical Control (barriers to prevent spread or traps)
  • Chemical Control (herbicides, insecticides, fungicides that are low-risk to the rest of the ecosystem yet effective and that can be applied when the pest is at its most vulnerable).
  • Cultural Management (selection of pest-resistant varieties of crops, mulching, winter cover crops, changing planting dates to minimize insect impact, burning, flooding, crop rotations)
  • Biological Controls (purposefully use enemies of an invasive species to reduce its population (predators, parasites, and pathogens).