High priority is given to the management of invasive exotic plant species that can harm park resources or people and can be controlled. Priority depends upon two independent factors:

• Degree and kind of biological, ecological, economic, or health threat.
• Cost and expectation of control, based on current distribution of the invasive species.

To be effective, the exotic plant manager seeks sound, scientifically based knowledge of the biology of potentially harmful exotic plant species, and networks with others regionally to learn the whereabouts of invasive plants. Insofar as possible, prevention is the most cost effective management approach. The park's Exotic Plant Management Plan links four categories of population distribution and density to corresponding appropriate strategic responses:

1. Present in region but not in park.
   • Ask whereabouts from cooperating agencies and landowners.
   • Place on a Watch List -- Educate park staff to seek and report.
   • Track spread if near park.
   • Prevent establishment inside park.
   • Avoid need for later control.
    
2. Present in park as individuals or small, localized populations.
   • If infestation is new, alert cooperating agencies and landowners.
   • Remove by hand.
   • Maintain a record of actions.
   • Monitor removal sites.
   • Follow up as needed.
   • Diligence keeps costs low.
    
3. Present as large infestations in parts of park. Native plant communities are disrupted and native species displaced from infested areas.
   • Remove outliers first.
   • Eliminate seed bank in outlier areas after removing plants.
   • Map large infestations. Plan larger attack projects. Cost permitting, implement one or more large-scale projects, as follows:
     • Contain spread to within infested areas.
     • Reduce the number and size of infestations.
     • Restore native species to bared sites.
     • Minimize dispersal and re-infestation.
     • Treat smallest, furthest outlying areas. first.
     • Eliminate larger infestations, moving from fringes toward the source of seed dispersal.
    
4. Present as continuous infestations within and beyond park boundaries. Displaces many or all native plants in areas of infestation.
   Complete control may be possible, but only by a coordinated, comprehensive effort between parks and neighboring agencies and land managers. Extensive planning and provision for public comment are needed. New and applied research may be required before control is possible or cost effective. Ways to share costs of eradication on a regional scale will be pursued. If costs are unreasonable, it may be possible only to restore and protect certain critical park areas from infestation. Control steps will be similar to 3.

http://www.nps.gov/redw/epstrat.htm
Last Update: June 12, 2001