Researchers from a variety of university program areas conduct invasive plant research to combat the threat of existing invasive species and prevent future invasions. Departments doing invasive plant research include Extension forestry, the Prairie Research Institute, the Department of Crop Sciences, the Department of Natural Resources and Environmental Sciences.
Results: Researches surveyed restored Illinois wetlands and analyzed herbaceous planta nd canopy cover. Hydrology has a role in determining plant species composition in restored wetlands. Problems related to invasive species can occur after restoration monitoring has ceased.
Research in progress: Reports of human tick-borne disease cases more than doubled from 2004 to 2016 in the US and this trend of increasing rates of tickborne diseases is also being reported in Illinois. Recent research has shown that invasive plants can increase risk to human and livestock health by increasing the proliferation of disease-transmitting ticks. However, not all invasive species may have the same effect. This research will investigate how changes in temperature and humidity due to infestations of invasive plants - bush honeysuckle, Japanese chaff flower, and Japanese stiltgrass - differ between species and how those changes influence tick populations and tick-borne disease carriage rates.
Results: Applying Glyphosate and Triclopyr during the flowering stage reduces viable seed production. This was not 100% effective, so do not use this as a primary method to control garlic mustard. This gives land managers an extra 2 to 3 weeks to apply herbicide to garlic mustard in the spring.
Results: Drone surveys provide access to remote areas while saving time and resources. Foresters identified mature amur bush honeysuckle, but small or fire-damaged plants escaped detection. There is a narrow window of time to get photos. In early fall canopies are still full of leaves, but invasive species had browned out in later flights. In the spring, early buds and leaves blocked the understory.
Results: When it was time to remove controlled invasions of Miscanthus giganteus and Miscanthus sinensis, the research team tracked what they spent on herbicides, equipment, travel, and personnel hours. The cost to manage the plant was $85 and $3,316 per site.
Results: Previous research has shown that many invasive species respond positively to fire, however, repeated fires at a high frequency can help suppress invasive plants over time by reducing nitrogen availability in soils.
Results: Large storm damaged areas are more heavily invaded and slower to recover than smaller areas. Storm-damaged areas were more invaded than nearby areas. The open canopy offered more light to understory invaders such as multiflora rose, Japanese honeysuckle, Amur honeysuckle, autumn olive, and Oriental bittersweet.
Management suggestion: Focus treatment in larger blowdown areas and on the most abundant invasives in the system.
Results: Dominant, exotic plants in wetlands reduce biodiversity and abundance more than dominant native plants do across Illinois. The dominant non-natives are not just choking out many other plants, the researchers report. They also have a broad ecological footprint, taking over wetlands on a regional level, rather than just in individual sites.
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Email: extension@illinois.edu