Invasive Phragmites huge risk (con't)
But Purple Loosestrife, which has been widely eradicated, has nothing on Phragmites, which may have been imported by that old culprit that brought zebra mussels to the Great Lakes – ocean-going freighters’ ballast.
The species originated in Eurasia and was identified by federal agriculture authorities as the “worst” invasive species.
In fact Phragmites (a Greek word pronounced Frag-Mite-EES meaning fence or screen) played a role in choking out Purple Loosestrife.
“Almost every wetland” locally has it to varying degrees, Lebedyk said. “It’s everywhere and quite aggressive.”
There is a native Phragmites species but it has nothing on the invasive kind.
Native Phragmites grows in a much sparser way and co-exists with other plants.
Not so with this thick “bamboo” - like plant, that can grow 15 ft. high.
“It basically chokes everything out so densely that nothing else actually utilizes the habitat,” Lebedyk said.
The stems grow in thick profusion, crowding out other plants.
It even prevents animals like frogs or fish from passing through streams because of its wall-like consistency, with previous year stems remaining standing while new stems grow up in-between.
“And so it just keeps getting thicker and thicker over time,” Lebedyk said.
The plant likes shallow water usually no more than half a metre deep.
Lebedyk said amelioration programs are weak and largely ineffective because the plant is so tough, its seeds can spread easily, and eradication is labour intensive and expensive.
Eradication works best on very small patches but there has to be extensive monitoring as part of a “long term program.”
Controls used can be mowing, burning and the spraying of new shoots with an herbicide.
“But the problem,” Lebedyk continued, “is it’s not just a one-time cure. It’s something you have to keep at over the long term.”
The invasion also has implications for agriculture, preventing water in drains from flowing freely.
The seeds are easily spread where they can “regenerate new populations,” the biologist said.
“And there is so much of this all over the place in Ontario that controlling your patch on your property becomes a never ending battle because you’re always being re-invaded by the larger population.”
Phragmites are changing the look of once diverse marshlands.
They’re identified by a wall of beige or tan grasses, creating a monoculture by choking out other marsh plants like cattails and bulrushes.
Purple Loosestrife was eventually controlled by the release of a particular type of beetle, reared at the University of Guelph, which ate the plants.
Lebedyk thinks a similar solution is “probably our only hope.”
But even here “it’s probably not going to be as easy.”
That’s because insects that would prefer Phragmites, a grass species, could easily switch to other grasses including crops like corn and wheat, and even golf courses and household lawns.
Universities in Sweden and the United States are working on such a "biological" control.
Until such a breakthrough occurs it will be next to impossible to get rid of the harmful grass.
Said Lebedyk: “You might as well just throw your hands up and say, ‘I really don’t have a solution to this’ unless everybody all at once throughout Ontario goes on a massive control program. Otherwise it’s just going to be almost futile.”