Volunteer Training at the National Bison Range
    (c) Mandy Tu/The Nature Conservancy

Engaging volunteers in the fight against invasive species is an integral part of the National Wildlife Refuge System’s (NWRS) management approach. It helps expand citizen participation in refuge operations while supporting the early detection of newly invading non-native species on refuge lands. Over the past few years, a new program has made this possible with support from a special Congressional appropriation to the U.S. Fish & Wildlife Service.

Non-native invasive species crowd out native wildlife and damage valuable habitat, making them the number one threat to the nation's 100-million-acre National Wildlife Refuge System. Rates of spread of invasive plants vary widely according to species and ecosystem type. On western lands conservative estimates of aggregate weed spread range from 10% to 15% per year.1 In contrast, individual species like the tropical soda apple that are invading hotter, wetter parts of the U.S. such as Florida are reported to have average annual spread rates as high as 117%.2

Although exact mitigation strategies are specialized and depend on the ecosystem and the species involved, the total estimated cost of fighting these invaders on refuges is significant. For example, in late 2002, the National Wildlife Refuge Association released its Silent Invasion report (pdf), calling on Congress to initiate a five-year $150-million strategy aimed at invasive species on our refuges. Some funding has become available, but the problem still needs to be addressed in a significant way. (NWRS Invasive Species Fact Sheet (pdf))

1Asher, J., and S. Dewey. Estimated Annual Rates of Weed Spread on Western Federal Wildlands. Draft white paper. December 2005. Federal Interagency Committee for Management of Noxious and Exotic Weeds (FICMNEW). 4 pg.

2Duncan, C. A, and J.J. Jachetta, Invasive Plants of Range and Wildlands and their Environmental, Economic, and Societal Impacts, 2005. Weed Science Society of America, 222pg.

Online Training Program for Volunteers and Staff

Online Training Module

In collaboration with the Center for Invasive Plant Management(, the NWRS has developed an invasive plant online training program for volunteers. Designed for National Wildlife Refuge volunteers and Friends groups, the program provides science-based, introductory information that is suitable for anyone interested in learning about invasive plants. The five self-study modules address the purpose and history of the Refuge System, how refuges manage invasive plants and how volunteers are assisting them. It also contains tips and tools for community outreach. Each module contains a quiz and web-based resources that enable learners to explore topics more thoroughly. The NWRS also has online invasives training for staff.

    Volunteer Training at San Pablo Bay NWR, CA
    (c) Mandy Tu/The Nature Conservancy

Competitive Allocation

Through this program, funding is awarded to refuge projects that directly involve refuge Friends groups and other volunteers. A wide variety of volunteers, including college and university students, the Boy Scouts and Girl Scouts of America, high school biology classes, Master Naturalists, garden clubs, adjacent landowners, and interested citizens, have become engaged in managing invasive species on refuges. The Student Conservation Association, Americorp, and the Youth Conservation Corps have also been actively involved. Over the past couple of years, funding awarded to refuges through competitive allocation for invasives species management projects has enabled nearly 2000 volunteers to contribute over 33,000 hours to the treatment, inventory and restoration of about 140,000 refuge acres.

One of these projects made national news when it was featured on “The Early Show” on CBS (February 13th, 2007). Parker River National Wildlife Refuge (NWR) joined forces with the Massachusetts Audubon Society to control perennial pepperweed.  Volunteers helped to establish a control zone or "fire lane" north of the Refuge where existing stands are a source of seeds that re-colonize refuge land and thwart efforts to preserve the marsh's integrity.  Perennial pepperweed is a relatively new invasive plant to northeastern United States, and currently has been documented in only Massachusetts and Connecticut. Eradication of this invasive plant is likely at Parker River Refuge and surrounding watershed through early detection and coordinated control with partners and private landowners. Volunteer groups included the Gulf of Maine Institute Teams from Newburyport and Lowell, Newburyport High School Students, Groundwork Lawrence (Middle school children) and First Year Student Outreach from Boston University.

Invasive Plant Mapping Project

A weed might be the last thing you'd expect global positioning system (GPS) technology to track, but this program has enabled the NWRS to train volunteers and staff to map infestations of invasive plants using hand-held computers and GPS units. In partnership with volunteers, the National Wildlife Refuge Association, The Nature Conservancy, and the National Institute of Invasive Species Science (NIISS) of the US Geological Survey, the NWRS is tracking and assessing the harm done from non-native plants to native ecosystems on refuges lands.

    Volunteer Training at the Pondicherry unit of Silvio O. Conte NWR
    (c) Mandy Tu/The Nature Conservancy

Volunteers are trained to identify locally important non-native and invasive plant species. They are also taught how to use a hand-held GPS device in order to pinpoint the exact location and extent of spread of the target species. Collected data are entered into a national database built and maintained by the National Institute of Invasive Species Science in Ft. Collins, Colorado, and used by the US Fish and Wildlife Service to prioritize its efforts in controlling invasive species. An important component of the program has been the early detection of incipient infestations. Volunteers are notified of invasive species present in the surrounding area and asked to be on the look out for these species on the refuge. Rapid response to small infestations is generally much more cost effective than waiting until a population gets out of control. Two types of software applications are used to collect the data: The Nature Conservancy’s Weed Information Management System (WIMS) originally developed by the Bureau of Land Management (BLM) and adapted by The Nature Conservancy, and the Refuge System’s geodatabase, Refuge Lands GIS (RLGIS) (website under construction).

An additional component of the project focuses on modeling. This component attempts to predict areas on a refuge that might be susceptible to invasion by non-native plant species. For example, the National Elk Refuge in north-western Wyoming extends over 9,720 hectares and is characterized by grasslands, sage-dominated shrub, and sparse forests. It would take many months for a team to survey and map this refuge’s large landscape. Therefore, in order to make the efforts at National Elk Refuge - and elsewhere - more effective, a team from USGS’s National Institute for Invasive Species Science (NIISS) used plot and mapping data, vegetation maps and other spatial layers to develop predictive models that identify areas of the refuge most vulnerable to invasion. (Art and Science article (pdf) illustrates this approach). Informed by this data, refuge managers can better direct the on-the-ground efforts of volunteer mappers to specified areas where there is a high probability that invasive plants are taking hold.

To date, close to 24,000 acres of refuge lands, in addition to hundreds of water bodies, have been inventoried and mapped through the mapping project by a corps of nearly 200 trained volunteers. This hard work by dedicated volunteers has provided valuable baseline data on the extent of invasive plant infestations on refuges, which in turn has assisted refuge managers in planning and prioritizing management actions and funding. Refuges participating in the program for the second and third year have engaged hundreds of additional volunteers in invasive plant management actions, such as control and restoration measures.

Click on a state below for a list of refuges and corresponding projects engaging volunteers in the fight against invasive species.

(Click on a state above to read more)

Alabama | Alaska | Arizona | Arkansas | California | Colorado | Connecticut | Delaware | Florida | Georgia | Hawaii | Idaho | Illinois| Indiana | Iowa | Kansas | Louisiana | Maine | Maryland | Massachusetts | Michigan | Minnesota | Mississippi | Missouri | Montana | Nevada | New Hampshire | New Jersey | New York | North Carolina | North Dakota | Ohio | Oklahoma | Oregon | Pacific Islands | Puerto Rico | Rhode Island | South Carolina | South Dakota | Tennessee | Texas | Utah | Vermont | Virginia | Virgin Islands | Washington | West Virginia | Wisconsin | Wyoming


Visit the websites of partners in the Invasives and Volunteers Program to learn more about their work to combat invasive species: