Publisher’s Perspective

By Tim Douglass, Publisher of the Pope County Tribune

The Buckthorn Brigade and the goats at Barsness Park may soon get a little help from science in the battle against buckthorn.

A group of volunteers called the Buckthorn Brigade started tackling the challenge of removing and mitigating the growth of buckthorn in the park.  They pulled the stuff by hand, cut out the larger plants and used larger equipment to mulch large swaths of the invasive plant.  The group, with help from the city of Glenwood, also brought in goats because of their love for mun ching on buckthorn.   All those efforts are working, but buckthorn springs back to life like a zombie, a pernicious invasive, with multiple strategies to outcompete native plants and take over a landscape.

But this week, we read a report from the StarTribune that stated that  University of Minnesota scientists are studying whether they can turn the plant on itself, exploiting an orange fungus that buckthorn hosts. If they succeed, the result could be the first environmentally friendly natural biocontrol, other than hungry goats, for a famously tough-to-kill plant.

According to the StarTribune report, researchers tried for years to find an insect to do the job, with no success. Meanwhile, the invasion of buckthorn and its removal is estimated to have cost Minnesota millions, not including all the hard-to-quantify impacts from lost native biodiversity, according to Mike Schuster, an invasive plant specialist in the university’s Department of Forest Resources.

The new potential ally is crown rust, or Puccinia coronata, a fungus found on most buckthorn plants in the state. Crown rust is a notorious attacker of wheat, oats and barley that’s been studied for more than 100 years, but never for the potential to control its buckthorn host, said Pablo Olivera Firpo, the U of M plant pathologist leading the project.

Crown rust starts out looking like orange measles on buckthorn then grows into raised cluster cups, a mass of little spore-spreading tubes. Some of the masses resemble a fuzzy caterpillar crawling up a stem.

At this point, nobody knows how many of the 17 known crown rust species in the world exist in Minnesota, or which ones are most destructive to buckthorn. Olivera Firpo’s team plans to figure that out with a three-year $364,000 grant from the Minnesota Invasive Terrestrial Plants and Pests Center, supported by the lottery-funded Environment and Natural Resources Trust Fund.

If they find a suitable strain that doesn’t affect crops, researchers plan to attack the buckthorn using a mat of straw infected with the fungus. After buckthorn trees and shrubs have been hacked down, the mat would be spread over the area to stop the prolific seedlings from re-sprouting.

For now, researchers at the U of M  are collecting hundreds of samples of crown rust-infected buckthorn plants. Common buckthorn, the most prevalent in Minnesota, and glossy buckthorn are the two species brought to Minnesota in the 1800s as ornamental shrubs and privacy hedges. The state now restricts them as noxious weeds.

The answers can’t come fast enough.

Everything about buckthorn seems designed to make it thrive. The berries on female plants contain a laxative ensuring birds spread it widely, and the roots emit a chemical in the soil that inhibits other plants.

As the Buckthorn Brigade knows, buckthorn is a nightmare to remove.  James Shaffer, natural resources supervisor for the Minneapolis Parks and Recreation Board, said  he’d love a non-herbicide option: “I’ve been hoping to see something like this pop up.”

We’ll keep our fingers crossed and meanwhile local efforts to remove buckthorn from Barsness Park will continue.