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Invasive Species

Invasive species pose one of the greatest threats to Illinois' natural areas, native communities, and natural resources. Species that are rare or declining are often at greatest risk of invasive species because of their few numbers or inability to adapt to changes in habitat. In Illinois, 62% of the wildlife species determined to be in greatest need of conservation are threatened, at least in part, by invasive species. Coordination of management efforts across a landscape is vital to effectively addressing these invasive species, detecting new infestations, and reducing redundancy. In Illinois, the Wildlife Action Plan (IWAP) sets goals and actions for conservation across the state, including an Invasive Species Campaign (ISC). The ISC identifies those actions determined to be most needed for statewide management of all groups of invasive species.

Goals and Actions

  1. A comprehensive, integrated approach is essential to effectively addressing invasive species.
    1. development of a strategy for preventing, controlling and managing biological invasions
    2. inter-agency moratorium on the recommendation, use and distribution of exotic species that are known to be detrimental
    3. inter-agency promotion of native species for environmental applications and wildlife habitat
    4. inter-agency coordination for effective and rapid detection, quarantine, eradication and control of invasive species
    5. cooperation with transportation, agricultural, and pet trade industries to curb introductions of invasive species.
    6. cooperate with horticulture industry to reduce reliance on nonnative species and increase use of native species for landscaping
    7. establish a trust fund with revenues from sales of intentionally introduced species for funding detection, eradication and control of plants and animals that escape cultivation or captivity
    8. improved control of the transport and release of live wildlife, including bait fish, cervids and feral hogs
    9. implement ballast water standards developed by U.S. Coast Guard
    10. draft and implement Rapid Response plans the Great Lakes basin and Mississippi River basin, covering all of Illinois
  2. Fill information gaps and develop conservation actions to address stresses.
    1. evaluation of established invasive species with the greatest damage potential and possibilities for control to focus control efforts.
    2. further research for screening species prior to introduction
    3. development of more effective and cost-effective control techniques (e.g., biological control measures)
    4. production of native cultivars to replace invasive species applications
    5. model biological invasions that might be facilitated or caused by climate change
    6. create "Invasive Species Center" at the Illinois Natural History Survey to coordinate research, knowledge sharing
  3. Prioritize high-quality natural areas, large habitat patches, and other key locations for invasive species
    1. improved surveillance for early detection and resources for rapid response to new invasions
    2. maintain on-going control (chemical, mechanical and biological) of invasive species, until species are evaluated and prioritized for control and/or more effective techniques become available
  4. Marketing, education, technical assistance, incentives and cost-sharing to prevent invasions, control invasive species (mechanical, chemical and biological), and restore natural disturbance regimes (e.g., fire) on private lands.

Priority Places for Work

Mermet Lake State Conservation Area

Mermet Lake State Conservation Area and the Cache River natural areas provide significant habitat for a number of species dependent on backwater sloughs, rivers and swamps. Mermet Lake State Conservation Area has been selected as an IDNR-managed site to highlight the Invasive Species Campaign section of the IWAP because of ongoing efforts to eradicate an infestation of curlyleaf pondweed (Potamogeton crispus). Curlyleaf pondweed grows and spreads rapidly in early spring of each year forming large, dense weed beds that nearly cover the entire lake by late spring. This exotic plant then senesces into dormancy during summer, releasing significant nutrients into the water column which encourages phytoplankton blooms and subsequent oxygen-related fish kills. The monoculture of curlyleaf pondweed contributes to low plant diversity and threatens the stability and long-term viability of the Mermet Lake ecosystem. Since 2009, IDNR has been implementing an eradication program for curly pondweed at Mermet Lake. These efforts have resulted in a drastic reduction in curlypondweed and resurgence of the fish population into the ecosystem. The efforts need to continue to assure eradication and complete restoration.

Pyramid State Park

Pyramid State Park provides a significant habitat for a number of species dependent on grassland habitat. Pyramid State Park has been selected as an IDNR-managed site to highlight the Invasive Species Campaign Section of the IWAP because non-native and invasive species are significant threats to both the grassland and wetland communities at Pyramid SRA. If left unchecked, these non-native and invasive species will cause the loss of both biodiversity and the degradation of associated wildlife habitat that is present and projected to be developed on the complex. Grassland habitat is becoming increasingly rare in Illinois, a problem compounded by loss of haylands, the reduction of pastureland statewide and high commodity prices that pressure landowners to convert CRP acreage back into row crop production. IDNR is both actively establishing new and maintaining existing grassland habitat at Pyramid State Park. Invasive species control is a major component of management at Pyramid State Park and vital to IDNR's efforts to provide critical grassland habitat.

Giant City State Park

Giant City State Park provides habitat for a number of species dependent on forestlands. In addition, Giant City State Park represents a well visited, highly visible property. Giant City State Park has been selected as an IDNR-managed site to highlight the Invasive Species Campaign Section of the IWAP because Invasive Species are a primary threat to the ecological and recreational management of Giant City State Park. Giant City has several listed species that are directly threatened by invasive species. Giant City has an invasive species management plan developed for the property and the Friends of Giant City, Southern Illinois Strike Team, and the River to River Cooperative Weed Management Area are actively involved in invasive species management and education at the park. The park has an established Demonstration Trail at the Visitor's Center to demonstrate the impacts of invasive species and the benefits that can be gained from management.


Invasive Species Programs

Illinois Invasive Species Management and Control

Invasive Species Laws, Regulations, Ordinances and Policies in Illinois

Invasive Species Distribution Information

Invasive Species Research in Illinois

Illinois Invasive Species Education and Outreach

Invasive Species and Stewardship Volunteer Opportunities in Illinois

Illinois Cooperative Weed Management Areas

Regional and National Invasive Species Resources

Federal Government Invasive Species Programs


Todd Strole
Program Section Manager
Illinois Department of Natural Resources
One Natural Resources Way
Springfield, IL 62702-1271
(217) 557-5059