Hot, Dry Weather Helps Noxious Weeds Thrive In Glacier National Park

Jul 29, 2015

The story of noxious weeds is the classic love story gone wrong. You see that beautiful so-and-so across the room, you hang out for a while, decide to move in together. But then you realize they’ve taken over your home, replaced your favorite stuff with useless junk and now you can’t seem to break up.

"And that is how this problem started. We brought in a lot of these invasive plants that have invasive characteristics because they’re pretty. And people let them grow and mow around them and they continue to set seeds."

That’s Dawn LaFleur, a restoration biologist for Glacier National Park. She names a few good-looking plants that have a habit of winning over gardener’s affection, at least at first.

"Oxeye daisies, St. John’s Wort, they are beautiful flowers. But if they do have them in their garden, they will eventually take over their garden and take over their lawn.

During the Noxious Weed Blitz last week, an event put on by the Glacier National Park Citizens Science Program, over a dozen volunteers spent the day learning about invasive plants in the park and how to ID and remove them.

Animals in the park can’t eat most noxious weeds. So when a weed out-competes a native plant for growing space, it removes a food source.

Also, when an invasive weed takes over a landscape and becomes the only type of root in the earth, it can  lead to soil erosion, which can hurt water resources.

There are five main noxious weeds that LaFleur says people should pay attention to: spotted knapweed, oxeye daisies, St. John's Wort, houndstongue, and yellow toadflax, also known as butter and eggs.

LaFluer says the park is seeing an increase of these kinds of plants.

"I think it is the combination of people, increased traffic, increased tourism, but also changes in the climate. It’s a combination of both."

LaFleur says the hot, dry spring and summer we’re having is giving noxious weeds big growing year.

"And right now what we are seeing is a longer growing season."

And opportunistic invasive plants, take advantage of that.

"So the potential, if we stay hot and dry through the fall, the a potential for a second growing season. So they can set even more seeds. Yeah, we didn’t know if it being so dry would knock back some of them, but we are seeing the noxious weeds take advantage of it and having a banner year," LeFleur says.

The crew in charge of spraying and picking noxious weeds in the park is having a tough time keeping up with how much the weeds are growing.

David Nadel is in his sixth summer with the crew.

"This year, everything sort of came on at once. Some years you see things staggered in different areas of the park. So we can hit the west side earlier cause the east side higher, is a different kind of climate. But this year is just seemed like everything just really quickly went to flower… That’s one thing we’re noticing, the shorter season and that’s going to make it a lot harder on us."

The six-person restoration crew is setup with backpack sprayers, a utility terrain vehicle and a truck, but the park’s size makes weed control a difficult task.

"We’re not able to, because we have such a small crew, cover as much ground. We have six people out spraying, for the entire park. And we’re on the west side but we go over to Two-Med, the North Fork, Rising Sun, Many-Glacier meadows. There is a lot of ground to cover. And that’s not including the backcountry."

Funding the crew is a struggle every year, according to Dawn LaFleur. She says the program is mostly funded by written grants. Money does comes from the park service but she say most of that funding allotment is decided in Washington D.C and out of her control.

LaFleur doesn’t think there is a strong enough voice on the Washington level to bring the fight against invasive species appropriate funding.

The National Park Service does recognize the spread of invasive species as one of the major factors contributing to ecosystem change and instability.

Nationally, 5 percent of park lands are dominated by invasive plants.

See a full list of Montana’s noxious weeds here.