Combating Invasive Plants In Wisconsin

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• Scientists, Residents Needed To Control Spread Of Invasive Plants

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  For many people, the natural beauty of Wisconsin is one of the best things about living here. There are many wonderful native species and ecosystems to enjoy, but when invasive species arrive and start to take over, it doesn’t take much to throw those delicate systems out of balance.

  Kelly Kearns, the plant conservation program manager with the Natural Heritage Conservation Program of the Wisconsin Department of Natural Resources, said that by both state and federal legal definitions, invasive species are non-native to a particular area. In addition, those non-native species must cause “ecological damage, or harm to human health, or even economic damage.”

  For example, Kearns said, “something that gets into a forest, like buckthorn or garlic mustard, and actually impacts the ecology of that forest and prevents other trees from growing: those things would be called invasive species.”

  One of the tricky aspects of dealing with invasive species is the variety of ways that they arrive in a location. Kearns said that most invasive invertebrates are introduced accidentally, often in soil and plant products. That includes both aquatic species like mussels and snails and terrestrial varieties like the emerald ash borer.

  With invasive plants, she said, some were also introduced accidentally, but others were brought here intentionally. “A lot of those coming in more recently were brought in as ornamentals for planting, for landscaping, for erosion control, or forage for cattle” Kearns said.

  While there are many invasive plants around the state, Kearns said that reed canary grass is the most common. Using visual imaging technology, it is clear that not only is it widespread, “a very large percentage of our wetlands are actually dominated by reed canary grass,” Kearns said, “and there’s a large number of others where reed canary is a part of them.”

  Reed canary grass is an unfortunate example of what happens when not enough is known and understood about ecosystems. Kearns explained that farmers looked at wetlands as “wet wastelands,” and thought they were making a positive change by planting reed canary grass as cattle forage directly into those areas.

  “We’ve since learned that there are other good reasons to maintain wetlands in their native state,” Kearns said.

  While professional biologists and wildlife ecologists are invaluable to efforts to control invasive species, residents can get involved, too. Regular monitoring helps to provide ongoing data of how different species are faring in the state, and volunteers are always needed. In addition, preventing the spread of invasive species is critical, she said.

  One of the newest invasive species to be found in Wisconsin is the New Zealand mudsnail. A tiny snail, they can cover the bottom of a stream bed and completely block access to food for native insects. That impact is then felt up the food chain. Because it has been found in Black Earth Creek, one of the state’s most popular trout streams, the risk of it being spread by people fishing is significant.

  Editor’s Note: Wisconsin Public Radio producer Judith Siers-Poisson recently took part in a citizen science project to help the state Department of Natural Resources screen water samples from around the state for New Zealand mudsnails. View photos above.