Pesticide Ban Failure | Conservation authority lifts Dundas Valley pesticide ban | Hamilton, Ontario and area

Conservation authority lifts Dundas Valley pesticide ban

Policy allows swift response to health threats, CAO says

By Richard Leitner, News Staff

The Hamilton Conservation Authority is lifting a ban on pesticide use in the DundasValleyas part of efforts to save key genetic trees from the emerald ash borer.

A new policy allows staff to apply pesticides and herbicides “as a last resort” to kill the tree-boring bug and other invasive or harmful species like giant hogweed, poison ivy and garlic mustard without first getting the OK from the board of directors.

Staff will still require prior approval for any large-scale use, like aerial spraying for gypsy moths.

Chief administrative officer Chris Firth-Eagland said the valley doesn’t presently have a problem with poison ivy or giant hogweed, but the policy lets staff act swiftly because of the health threat the plants pose.

He said the need to do so was underscored a couple of years ago when a volunteer at Westfield Heritage Village suffered disfiguring third-degree burns after getting oil from giant hogweed on her skin while tending a garden there.

“You’ve got to get rid of that plant immediately because someone could come in contact with it while you’re writing reports and getting authorizations,” Firth Eagland said.

“Cutting it down, bagging it and disposing of it is only part of the cure. They use a spray to kill it,” he said.

“You don’t want it to come back, and it has a habit of seeds being able to travel. It sometimes travels along watercourses and things of that nature, so in the big picture you want to eradicate it whenever you come across it.”

Firth-Eagland said the policy will also allow staff to save some “amazing genetic, seed-bank-type ash trees” by applying TreeAzin, a natural pesticide made from the seeds of a tree native toSouth Asia.

Selected trees will require injections at least every two years for eight to 10 years at a cost of $210 per treatment for a midsized tree.

“A lot of times with invasive species, the environment adapts to them, they go away or some other species learns to prey upon them. Nature has a way of balancing out things over time,” Firth-Eagland said.

“The idea is that if you could control the emerald ash borer for an eight to 10 year period at a certain known cost and you’ve saved the seed bank, then it can reintroduce itself into the forest as appropriate and you’ve kind of survived the wave.”

A related protocol passed by directors will also allow staff to use TreeAzin on significant, healthy landscape ash trees at conservation areas.

Scott Peck, director of watershed planning, told the authority’s conservation advisory board in June the protocol will leave most dead or dying ash trees in larger wooded areas alone, but those by public trails or locations posing a safety hazard will be cut down.

He said the authority will also plant new ash trees in forests where their loss has a significant impact.

A staff report states that ash trees make up between 50 and 60 per cent of the forest canopy at nine conservation areas:VinemountSwamp,DundasValley, Fifty Point,ChristieLake,BeverlySwamp, Spencer Gorge, Copetown Bog,IroquoiaHeightsand Meadowlands.

TheVinemountSwamp, closed to the public since May because of a high number of dead trees, has the biggest concentration of ashes and may require restoration.

“At this threshold the loss of ash will have a detrimental impact to the health of the forest and to the potential for invasion or expansion of non-native invasive species,” the report states.

According to Natural Resources Canada’s website, TreeAzin is derived from the seeds of the neem tree, a tropical broadleaf evergreen, and has been specifically designed for use against wood boring pests.

The trees’ organic compounds have also been used inIndiafor centuries to protect crops from pest insects, it states.

The authority’s approach to ashes differs from that taken by the city, which plans to remove dead or dying trees.

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