The City of Montreal will chop down 4,000 ash trees on picturesque Mount Royal because they have been attacked by an invasive strain of beetle from Asia.
"This isn't a decision we're making lightly, cutting trees on Mount Royal, 4,000 is a lot," Coun. Luc Ferrandez, the executive committee member responsible for parks, said Wednesday.
"It isn't good news, but the way we're responding is good."
Natural Resources Canada says the emerald ash borer has killed millions of ash trees in southwestern Ontario, Michigan and surrounding states and "poses a major economic and environmental threat to urban and forested areas in both countries."
The beetle was first detected in Canada and the United States in 2002 and spread east quickly to regions where ash trees were prevalent.
In Montreal, officials awarded a contract to have the trees felled in the next year as they are deemed too far gone to receive the required insecticide treatment.
Ferrandez said the cutting won't leave any visual effect on the landscape and that the city will plant 40,000 replacement trees, mainly red oaks and maples.
Jim Fyles, director of the Morgan Arboretum and Molson Nature Reserve at McGill University, says 4,000 is still but a small percentage of the mountain's entire forest canopy of more than 100,000 trees of various types.
"We have the emerald ash borer that is working its way through Montreal and lots of trees have been cut in the last five years," said Fyles.
"Likely those trees (identified by the city) will die between now and five years from now or 10 years from now and, in that situation, it's prudent to be proactive about it."
Montreal and other communities have invested in a treatment, required every two years, at a heavy cost, depending on tree size.
Scientists with the Canadian Forest Service, which is part of Natural Resources Canada, have estimated that costs to Canadian communities for treatment, removal and replacement of affected trees could be $2 billion over a 30-year period. There would also be other environmental impacts.
The beetle has also been identified in 21 U.S. states and Fyles said some of those jurisdictions have lost all of their ash trees.
"We're more or less at the northern edge of where the emerald ash borer is now," he said, adding it hasn't moved as quickly as he thought it might.
It's hard to say how long the species will survive but, without ash trees, they starve and don't move on to other types of trees.
"Eventually, the whole thing will stabilize a bit because the treated ones will be healthy and untreated ones will be dead, but that's how it's unfolding now," Fyles said.