City ready to fight pest
Nov. 9, 2016
By Matt Vis
Thunder Bay will mount a direct fight against the emerald ash borer as evidence shows the tree-killing beetle is spreading across the city.
Council on Monday voted to approve administration’s recommendation to adopt a $6.3 million active management program over 10 years of treating and protecting 50 per cent of eligible ash trees against the invasive species.
The emerald ash borer was first found in Thunder Bay in June in the area of Memorial and Fourth avenues. Signs of the beetle were also found in the immediate vicinity, within 500 metres.
But Rena Viehbeck, the city’s urban forest program specialist, said other finds have been made in opposite directions of the inital detection with one on the north side about two kilometres away and then another three kilometres from the first spot.
“It’s recommended in order to begin treatment of ash trees, if you’re wanting to protect them, it should be done when emerald ash borer is found within 25 kilometres,” Viehbeck said. “That really comprises our entire city.”
There have been a total of eight emerald ash borer finds so far in the city. They have been found in the areas of First Avenue, Fourth Avenue, Sixth Avenue, High Street, Memorial Avenue, Frankwood Avenue and Norah Street. The report presented to council indicates the beetle could have been in the city undeteced for three years.
Ash trees are estimated to make up 25 per cent of the city’s urban forest canopy, meaning the decimation of the trees will have a significant impact.
Three options were presented to council: One was a “do nothing” plan, where there would have been no preventative measures taken and affected trees would be removed as required. That plan would have carried an estimated price tag of $7.6 million over a 10-year period. A second strategy would have called for the treatment of 30 per cent of trees with the remainder removed, which was pegged at a cost of $6.8 million over the decade.
The direction council decided carries the lowest price - at $6.3 million - and is intended to save the highest rate of trees at 50 per cent.
That will come at a cost of $550,000 in next year’s budget, which will begin treatment on 850 trees and remove 250 others that are in decline, poor health or poor structure with those replaced by new, re-planted trees.
“This is the most cost efficient model,” Viehbeck said.
“By preserving some of our ash trees, we save money by not having to remove and replace them and we’re also benefitting from the services they provide while they stand. It would end up costing much more to let the trees die and trees become much more hazardous and difficult to remove once they are infected.”
There are 6,300 ash trees on city-owned property, which includes streets, boulevards, parks and cemeteries. Of those, 3,400 are deemed eligible for treatment, which means 1,700 will be selected to protect.
Viehbeck said eligible trees will have a diamter of at least 20 centimetres, adding it is not cost effective to protect younger trees because they would require longer treatment.
The emerald ash borer was first noticed in North America in 2002 in the Detroit and Windsor area. Since then it has gradually spread across the continent, leaving ravaged forests in its wake.
“In some ways we’ve been preparing for the emerald ash borer without doing anything too active,” Viehbeck said. “We haven’t planted ash trees in the city for about 10 years so we have been bringing down our percentage of ash trees but it is still a significant component of our urban forest.”
Administration will begin developing a 10-year implementation plan for the strategy.