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'Evil crab grass on steroids' moves into Alberta: Phragmites australis can grow over five metres high and chokes out natural ecosystems

02/13/2018

By Dave Gilson, CBC News Posted: Feb 12, 2018 10:07 AM MTLast Updated: Feb 12, 2018 10:07 AM MT

Crews work to get rid of a patch of Phragmites australis near Brooks, Alta.

Crews work to get rid of a patch of Phragmites australis near Brooks, Alta. (County of Newell)

A towering invasive plant that has wreaked havoc in easternCanada and the United States is now being tracked in Alberta.

Officials here say it's unclear how long Phragmitesaustralis has been in the province, but they've pinpointed more than a dozensmall stands within an area stretching from the southern grasslands to thePeace Region.

The reed, which grows in thick stands and can reach heightsof over five metres, came to North America from Eurasia more than a centuryago. In recent years, it's been called one of the country's worst invasiveplants.

"If you want to picture it in terms of a prairie plantthat we know, it's basically evil crab grass on steroids," said CalgaryZoo plant expert Boyd Nave.

"It takes over large swaths of wetland. It literallydrives out other plant species because it grows so incredibly densely."

'Horrible to get rid of'

Birds, mammals and fish are also affected as habitats arealtered or destroyed by the plant, which has been designated a threat under thefisheries act.

Nave says controlling its spread has been a challenge outeast, where the plant has thrived in wetlands from Nova Scotia to southernOntario, using seeds and shoots to colonize an area.

Invasive plant phragmites a strain on wildlife, localresources

"It is absolutely horrible to get rid of. It involvesapplying herbicide, which is kind of dodgy, because you're near watercoursesoften, then it requires either cutting or burning and then it comes up againnext year and you kind of repeat," he said.

"A very large stand, your best hope is to control itsspread. You won't get rid of it."

Nicole Kimmel with Alberta Agriculture and Forestry saysthere are signs Phragmites australis is spreading west.

"We knew that it was likely to come here, we justdidn't think it would be this soon. We are better served here in Alberta, if wecan get on them when they're smaller rather than investing all that time whenthey get huge," she said.

"Any users of the water basin in Alberta could beaffected, and agriculture has a vested interest because of the irrigationinfrastructure that it's closely associated with down in the south."

Two day fight

Kimmel says all of the sites discovered so far in Albertahave been contained. The first was detected in 2016 near Brooks.  

Todd Green is the director of agricultural services with theCounty of Newell, which encompasses the town. He says that site was one ofthree stands identified and contained in the municipality that year.

"What we found on the site specifically was about13-feet tall and grew really thick ... in the thousands of plants in a verysmall patch," he said. 

"It replaced all the vegetation in this patch, nativevegetation whether it be cattails, reeds or anything like that."

Green says it took a 12-person crew two days to cut andremove the plants by hand from that one small stand. All of it was trucked to alocal landfill and buried.

He adds they also applied a herbicide the following year toprevent the plant from growing back. That step required special governmentapproval because the herbicide was being used in a wetlands area.

Gardens

Those tracking its spread believe the plant's seeds canhitchhike along transportation corridors including railways and highways, butthey point out it also found a commercial route into the province.

Before Phragmites australis was banned, it was once sold asan ornamental plant, along with other varieties of Phragmites, for lawns andponds.

Officials believe two of the identified Alberta Phragmitesaustralis sites were intentionally planted, including one at the Calgary Zoo.

Nave says the small stand was planted decades ago in one ofthe wildlife enclosures.

He says it only grows about five feet tall and hasn'tspread. He believes the invasive plant doesn't thrive in Calgary because of thealtitude and the colder climate.

Nave says the zoo will remove the stand this spring and saysit illustrates the point that Albertans need to check their properties.

"It's still growing in peoples' gardens and it's justthe idea we need awareness out there that this is a highly invasive plant,needs to be controlled. In fact it is illegal to grow it in your garden at thispoint."

Native varieties

Officials say there is a native variety of Phragmites andstress it doesn't pose an ecological threat.

Kimmel says the province expects to find more sitescontaining the invasive version, and while officials continue to monitorwetlands and waterways, they're asking the public to keep an eye out as well.

"I think we've got a pretty good handle on thepopulations we've been able to find. They've all been quite small and isolated,so I think we've got a chance of continuing to keep it eradicated."


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