RESEARCH PROGRAM > Larger Systems > Non-Native Species > WILDERNESS INVADERS: Surveys & Databases

LEOPOLD INSTITUTE   790 E. BECKWITH AVE.   MISSOULA, MT 59801   406-542-4190


Invasion by non-native species is widely recognized as one of the greatest threats to native biodiversity and natural ecosystems. Though wilderness and other protected areas often appear pristine to the casual observer, they are not immune to invasions by exotic plants, animals and pathogens. In an effort to collect baseline data on the presence, distribution, threat, and control of non-native species, the Leopold Institute has initiated two projects. The first was a survey of exotic plants in all federal wilderness areas. We more recently conducted a survey of invasive and exotic species in National Wildlife Refuge Wilderness Areas.

By making this invasive and exotic species' baseline data available to wilderness managers and other interested parties (see below), we hope to aid management efforts to prevent and control the spread of invasive species within wilderness areas. Information that can be accessed includes which species are problems in other wilderness areas, control methods that have been used on these species, and contact information for managers that are dealing with these species. By querying the databases, the following types of questions can be answered:

  • Which wilderness areas have salt cedar present?
  • Which areas are using biological agents to control Canada thistle?
  • What are some contacts for National Wildlife Refuge wilderness areas that have feral hogs?

Why special projects for Wilderness areas?

Invasive species in wilderness are of particular concern because the Wilderness Act of 1964 mandates that wilderness areas be maintained in their natural condition and because wilderness areas provide valuable ecological benchmarks by which we can measure environmental change. There have been several studies on the impacts of invasive species in other kinds of preserves, but the extent of invasions in Federal wilderness areas remains largely unknown.

Interagency Exotic Plant Survey and Database

In 1997-98, the Leopold Institute contracted with Marilyn Marler and the University of Montana to conduct a survey to investigate the extent of exotic plant invasions in Wilderness areas. Over 300 Wilderness areas managed by the Forest Service, Bureau of Land Management, Fish and Wildlife Service, and the National Park Service participated in the survey, which resulted in a database, a final report, and a publication (all available below).

Specific objectives of the survey were to:

  • Survey designated Wildernesses and areas managed as Wilderness.
  • Inventory exotic plant species that exist in Wilderness.
  • Characterize the quality of available data.
  • Inventory control measures that have been taken and compile information on their effectiveness.
  • Generate awareness of plant invasions in Wilderness areas and facilitate information exchange.
  • Identify research needs and priorities.

Download this database and its key.
In its current form, the database requires familiarity with Access (Microsoft Office 97). It contains contact information for participating Wilderness areas, exotic plant species reported for each participating Wilderness area and control measures being used for each. Thus, the database can be queried by species, by control method, by Wilderness area name, etc.

A publication detailing the findings of this survey can be downloaded as a pdf document from This report is cited as:

Marler, M. J. 2000. A Survey of Exotic Plants in Federal Wilderness Areas. Pages 318-327 in Cole, D. N., S. F. McCool, W. T. Borrie, J. O'Laughlin (Comps.). Wilderness science in a time of change: Wilderness ecosystems, threats, and management (Volume 5). Proc. RMRS-P-15-VOL-5. Ogden, UT. USFS, Rocky Mountain Research Station.

The final report is available from the Leopold Institute and can be downloaded as a pdf document from This report is cited as:

Marler, M. J. 1998. Wilderness invasion: Current status and future directions. Final report on file at: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Aldo Leopold Wilderness Research Institute, Missoula, MT. 44 p.

For further information on this project, please contact Vita Wright.

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National Wildlife Refuge Invasive and Exotic Species Survey and Database

In the summer of 2001, the Leopold Institute, in collaboration with the US Fish and Wildlife Service, conducted a survey of invasive and exotic species within National Wildlife Refuge wilderness areas. The Presidential Executive Order on Invasive Species (2/3/99) directed all federal agencies to prevent and control introductions of invasive species in a cost-effective and environmentally sound manner. Since the Executive Order, activities to prevent and control invasive plant and animal species have become a USF&WS priority on all National Wildlife Refuges. The primary purpose of this project is to develop a database that can function as an internet-based tool for monitoring the status of invasive species in specific wilderness areas and as a resource for information on invasive species problems and control measures in other refuges.

We collected information from FWS managers on the status and management of invasive plants and exotic animals and pathogens in National Wildlife Refuge wilderness areas. The surveys were completed in July 2001, and a summary report of the survey findings was completed in December 2002. The following 'Nutshell,' publication, summary report, survey form, and survey results are available.

RESEARCH IN A NUTSHELL: Invasive And Exotic Species In National Wildlife Refuge Wilderness Areas
Douglas Tempel, Amy Cilimburg, and Vita Wright

Tempel, D.J., A.B. Cilimburg, and V. Wright. 2004. The status and management of exotic and invasive species in national wildlife refuge wilderness areas. Natural Areas Journal 24(4): 300-306.

Detailed summary report (pdf)

Survey form (pdf)

Entire database (Microsoft Access)

Key to the database/tables (pdf)

For further information on this project, please contact Vita Wright.

Other database links