Give Invasive Plants the Brush Off

It’s the middle of the night, in the middle of nowhere, and you’re jockeying for a spot on the bank of the Au Sable River where trophy trout lie in wait. Fishing June’s legendary “hex hatch” means staying up late and timing your trip just right for the moment Michigan’s giant mayfly, Hexagenia limbata, emerges in swarms so massive they can be heard a hundred yards upstream.

This is the moment big trout have been waiting for, when they’ll slurp falling flies from the river’s surface. The same goes for Michigan’s most hardcore anglers who blindly cast their lines through the darkness toward the sounds of rising trout.

Amid this midnight feeding frenzy, miles away from the nearest sidewalk or street lamp, there’s bigger things to think about than where you’re stepping. Out here it’s just dirt trails, worn down by the boots of backpackers and anglers over generations. In daylight the river valley doesn’t look much different from one summer to the next, and the sport of fly fishing is a mostly unchanged tradition around the Au Sable River.

But in the treads of our boot heels and the folds of our clothes, the seeds of plants able to change this landscape in radical ways can hitch a ride through the valley without us ever noticing. When we pay attention to this fact, those plants lose the element of surprise.

Northern Michigan is host to dozens of invasive plant species, brought to the Midwest intentionally as ornamental shrubs or accidentally in the ballast water of ships then dispersed by humans, animals and natural forces. Three species in particular — Japanese barberry, garlic mustard and purple loosestrife — require serious attention to limit their spread within the Au Sable River watershed where they are already present.

“Japanese barberry is very prevalent along the Au Sable and the Mason Tract, a public trail system near Roscommon that follows the river,” said Shelby Bauer, Stewardship Team Lead for Huron Pines. “Studies find tick populations are much higher in barberry-infested areas because ticks are attracted to the plant’s shrubby nature and the small rodents that take shelter within them. I’ve found this to be true in my own experience in the field and this makes staying on paths really important.”

Huron Pines and its partners continue making strides in controlling these invasive species and there is still work to be done. In the meantime, these plants will continue causing trouble in areas where they’re established across Northern Michigan and we need to be vigilant about not helping them along.

Garlic mustard is not as widespread here as in southern parts of the state but is present along forest trails where it acts as ground cover and outcompetes tree seedlings and other native plants. It’s also a prolific seed producer and the tiny seeds are viable for up to 7 years.

Since 2012 Huron Pines has partnered with the U.S. Forest Service, Consumers Energy and students from Oscoda Area Schools to hand-pull hundreds of pounds of garlic mustard annually near Foote Dam, keeping the species in check while protecting a healthy population of wild ginger there.

Similar efforts against purple loosestrife by local watershed groups have helped keep this wetland wildflower at bay along the Au Sable River. It’s another significant seed producer, carried along by waders and watercraft that come in contact with ripe seed pods. Huron Pines plans to coordinate an event later this summer to remove purple loosestrife from areas of the watershed.

Knowing this information helps us be more conscious of where we’re walking but we can also equip ourselves with simple tools and practices to reduce the spread of invasive species. Consider taking these actions during your next outdoor adventure:

  • Pack a stiff-bristled brush and lint roller. Use the brush to clean seed-carrying dirt, mud and debris from your boots and treads regularly. This also works for waders and bike tires before and after each use.
  • Inspect and clean your clothes and gear between uses and locations. A lint roller is a fast and effective way to remove seeds from clothing.
  • Inspect and towel down watercraft between uses.
  • Remove burrs from pets. Tough burrs in thick fur can be helped out with a pinch of coconut oil.
  • Stay on marked trails as much as possible.

Help keep our shared outdoor spaces unchanged, and enjoy your time in the company of the Au Sable River.

By Chris Engle

Huron-Manistee National Forest of the U.S. Forest Service, U.S. Department of Agriculture and Huron Pines are working cooperatively to develop and implement educational and outreach activities related to non-native invasive species in the community and schools within the Mio and Huron Shores Rangers Districts.

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