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Invasive weed causes alarm in Alberta

12/12/2017

By Barb Glen

Published: November 30, 2017

Nicole Skanderup of the County of Newell stands in a patchof Phragmites australis. | Catherine Christensen/County of Newell photo

Phragmites australis chokes out other plants, destroyswetland ecosystems and can pose a fire hazard when it dies

It’s tall. It’s nasty. It’s invasive.

“It scares the crap out of us,” said Todd Green, director ofagricultural services for the County of Newell.

Green was speaking about Phragmites australis, a member ofthe reed family that was found in the county last year and has since been foundin 13 other Alberta locations.

Phragmites has spread widely in Ontario and parts of theUnited States but is assumed to be a relative newcomer to Alberta, althoughGreen said there’s no way of telling how long the pest had been growing in theprovince before it was identified.

Alberta has native varieties of Phragmites, but australis isan introduced species that can choke out other plants and destroy wetlandecosystems. It reduces habitat for fish and wildlife, and its dead stalks canbe a fire hazard.

It is tall, with feathery seed heads, and it favoursstanding water or generally moist conditions.

Green sounded a warning about the invasive plant at theAlberta Irrigation Projects Association conference in Lethbridge Nov. 22.

He thinks eradication is achievable in the province, but itwill require close monitoring.

“My understanding from the province is that all the sitesare containable,” he said in a later interview. “They’re not really large,widespread patches so we are still, we believe, in the eradication stage.”

The species is not listed under the Weed Control Act, whichis a complicating factor that limits proscribed action against the weed.

However, it is listed as a threat in the fisheries act,which provides for Alberta Environment involvement in control and eradicationefforts.

Green speculated that Phragmites australis arrived in theCounty of Newell, which is the region around Brooks, Alta., aboard a trainbecause the first patch was found along the Canadian Pacific Railway right ofway.

“We assume that’s how it came in was from a CPR train thatdropped off either a seed or a part of a plant,” he said.

 

“It is very close to an EID (Eastern Irrigation District)canal, kind of a slow drain into a wetland, and there’s a major canal just tothe south, so not good news for us.”

In 2016, county personnel cut down and removed a large patchof the reed within the EID using garden shears and tree trimmers. Fourtruckloads of the plant were buried in a landfill.

In 2017, special permits were obtained to spray, a trickyproposition when dealing with plants in water bodies. Only two products areregistered for control, imazapyr and glyphosate, but only the imazapyr productwas used, Green said.

Sites were sprayed in Newell and within the city of MedicineHat, where another patch was found along the CP line near Ross Creek.

As of now, the pest has been found as far away as GrandePrairie, mostly at sites associated with railways and roads. Green said it maybe spreading in shipments of grain, hay or straw.

Among its pesky properties is the reed’s ability to spreadby seed but also by rhizomes and sprouting from nodes along its stalks.

Green said it is taller than native varieties. Plants up to13 feet high were found in Newell in 2017, even though it was a very dry year.

It can also be distinguished from native varieties becauseit has a tan or brown colour on the stalk below the leaf sheath. Nativevarieties are red in that area.

As well, the seed head is larger on the invasive type.

Green said anyone who thinks they’ve seen a stand ofPhragmites australis should contact the agriculture services board in theregion so quick action can be taken.


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