Scientists call on Minnesota to combat invasive grass

There's still time to stop an invasive grass that's threatening to spread in wetlands across Minnesota, according to some scientists.

The Minnesota Aquatic Invasive Species Research Center is warning the state about invasive phragmites, an invasive strain of wetland grass that grows faster, taller and thicker than its native counterpart.

The center has identified about 400 populations of invasive phragmites species across the state, Minnesota Public Radio News reported.

If the species were to spread unchecked "in coastal marsh systems over time, it can turn a wetland with a lot of good hydrologic connectivity into something that's more like a meadow," said Dan Larkin, a professor at the University of Minnesota and a scientist at MAISRC.

Larkin said the plant is becoming a problem along the St. Louis River estuary near Duluth and wetlands near the Twin Cities, but most phragmites populations are still relatively small in the state.

"That's the stage at which control can be effective," Larkin said. "We see this as a window of opportunity where we can target populations at this stage and nip them in the bud before they get much larger and we see the really negative ecological impacts that have happened elsewhere."

Larkin and other scientists are urging Minnesota's Noxious Weed Advisory Committee to take action. Invasive phragmites is classified as a restricted noxious weed in Minnesota, which means it can't be sold or imported to the state.

The center wants the grass to be reclassified as a prohibited species, which would require the state to control or eradicate the plant.

The committee has voted to put phragmites on its prohibited list before, but received pushback from the Minnesota Department of Natural Resources for not having enough information about how widespread the invasive grass is.

MAISRC researchers said they have collected enough data to address the issue.

Heidi Wolf, who runs the agency's invasive species program, said the Department of Natural Resources declines to take a position on whether the phragmites should be prohibited yet.

Larkin said researchers are still looking into potential control methods, such as herbicide applications and timed mowing.

"This is not a lost cause," he said. "We think this could be a real opportunity to do something positive with an invasive species."