Foreign invaders

This summer’s abundant rainfall has revealed in more dramatic fashion than before a reality that has been increasingly difficult to avoid in recent years — foreign invasive plant species, like tansy and birdsfoot trefoil, are spreading at rates that are going to make control nearly impossible in the near future without immediate steps to halt their spread.
The spread of birdsfoot trefoil has been nothing short of astonishing in the past few years, and we’ve never seen a year like this one before. Roadsides in many areas have become choked with the plant, which is easily recognized by its bright yellow, snapdragon-like flowers. It’s a member of the pea family and it was introduced to the U.S. years ago for livestock forage. It’s also used in mineland reclamation for its dense growth, which can reduce erosion, and for its ability to fix nitrogen in the soil. It’s widely used on old mine sites here on the Iron Range, which is what likely first brought it to our area. The plant produces copious amounts of small seeds that are further spread around the region through the use of what’s commonly called “mill feed” here, which is a crushed taconite product that many people use for rural driveways or as a base for concrete slabs. Once established, the invasive trefoil grows so thickly that it can quickly choke out native plants.
It’s much of the same story with tansy. This tall plant, with its bright yellow, button-like flowers, also grows in ever denser stands, effectively wiping out native habitat. The plant itself is toxic and should not be fed to livestock. Even handling tansy can give humans a skin reaction, so anyone looking to remove the plant should definitely wear gloves.
The problem with these invasive plants is that once they reach a certain level of population, it becomes almost impossible to control them. We are very close to that tipping point with both tansy and trefoil in our region, and it’s just another sign of how humans are negatively impacting our environment.
Some of our activities are more likely to spread invasive species. The use or spread of any kind of aggregate these days is almost guaranteed to bring new infestations of these foreign invaders. Most gravel pits contain seeds from tansy, trefoil, and other non-native plants, so every load moved somewhere else simply exacerbates the problem.
Over the past few years, enormous amounts of aggregate have been spread in our region for the expansion of our ATV trail network. Each new trail put through the woods is another corridor opened for the uncontrolled spread of invasive species. The construction of the trails is one factor, but the ATVs themselves spread invasives as the tiny seeds from these plants get caught in the tires and caked mud and are subsequently dislodged along the various trails. Within just a year or two of opening, many ATV trails in our region are lined with invasive species. Each new trail extends the reach of these invasive species across the landscape.
The Department of Natural Resources is installing an ATV wash station at the new Murray Spur OHV campground still under construction near Soudan, but how many will take advantage of the wash? ATV clubs should take up this challenge to spread the word to their own members and maybe even play a role in addressing the problem. ATV clubs have shown themselves to be well-organized with members who are eager to play a role in furthering their sport by sponsoring rides for a variety of activities. Maybe a Weed Control Ride would be a good way to inform members on this issue and get folks out in the woods to help address problem areas that are contributing to the spread of these exotic invasives.
Cities and townships also need to do their part. Under state law, these local units of government are required to appoint a weed inspector, who is charged with enforcement of the state’s noxious weed law. Unfortunately, this law is rarely followed in our area.
We could also look for ways to engage young people on the issue. Some area school sites and school forests harbor plenty of these nasty invasives. Let’s harness some of that youthful energy to address the problem. We need to make the next generation aware of the problem and give them experience with control measures if we’re going to have any chance of keeping these plants in check. The North Woods is home to an amazing diversity of native plants that help to sustain our wildlife neighbors. Let’s not let ignorance and apathy on our part allow the continued spread of these nasty invasives in our region. We need to act soon before it’s too late.