Tree Canada president Michael Rosen says cities must be 'aggressive' in stomping out such threats as emerald ash borer

Saultstar.com
Sept. 26, 2017
By Jeffrey Ougler

A good chunk of Canada's character may be tied to trees.

The "sad truth," however, is that forest cover in Canada's cities has been chipped away over the past two decades, reports an Ottawa-based group that promotes the planting and nurturing of trees in urban and rural areas.

And this is happening despite ample public awareness about environmental issues, says Tree Canada president Michael Rosen.

"This is the biggest irony," Rosen told the Sault Star in a telephone interview from Ottawa. "We are much more green, we are much more conscience of the environment, people want trees. They seem to want trees in the city, but, unfortunately, there's a number of factors working against the situation that has allowed forest cover in all of our major cities to decline."

Climate change has "a lot" to do with this issue, Rosen said.

"It taking its toll, whether it's horrific storms or periods of drought in the summer or intense storms that trees just haven't evolved to take advantage of," he said.

Insects and disease are also major culprits.

Creating more tree-rich cities - Rosen dubs it "smart growth" - instead of "mindlessly" building more suburbs is wise. As long as it's done correctly.

"If the trees are not properly protected, they will die," Rosen said.

During this National Forest Week - Wednesday is National Tree Day - Tree Canada wants to get the message out about fostering healthy urban tree populations.

Emerald ash borer, native to Asia, is the worst alien pest problem to hit Ontario since Dutch elm disease. It has killed countless ash trees in cities in the Great Lake States and across the province.

Sault Ste. Marie has been plagued in recent years by the invasive beetle, which has claimed trees along Queen Street and other areas. City council heard last year replacing dead trees on Queen Street will cost about $2 million.

A report at the time said the majority of trees on Queen Street, between Bruce and East streets, were dead and those that were not, would be within the next year, or were structurally weak and could be claimed by severe weather. The previous year, city staff replaced trees between Dennis and Bruce streets with different species able to tolerate urban growing conditions.

TreeAzin treatments have also been used here to combat destruction of emerald ash trees in the downtown core. TreeAzin, a liquid injected into the base of each tree and sucked up through the tree's sap "vascular" system in three minutes, has proven to be extremely effective in staving off the beetle - it boasts a 94-per-cent success rate for healthy trees - but has not proven so potent if used after a tree is already infected.

Tree-saving efforts must be "aggressively handled," said Rosen, a registered professional forester educated at both The University of Toronto and The University of New Brunswick.

"We've had time to figure out what works and what doesn't," he said, adding many cities have passed bylaws, essentially "forcing" people, when they've discovered the insect, to be proactive.

Often, property owners are afforded two choices: treat the tree or cut it.

"Ignoring that is not an answer," Rosen said. "The problem is, the bug doesn't respect property boundaries. It will go to private trees and it will go to public trees. It doesn't care ... just whatever tree is close."

Such action has proved "very effective" in some jurisdictions, including Beaconsfield, Que., an on-island suburb on the Island of Montreal.

Along with applying TreeAzin, Beaconsfield installed Lindgren funnel traps to entice and ultimately kill the green metallic beetle. That community has budgeted $300,000 for ash-borer TreeAzin treatment this year, with money divided equally between treatment of ash trees on public and on private property.

City councils, Rosen said, must take the lead.

"They have to be quite aggressive and they have to be prepared to pass bylaws that are really going to tell people what they can do with their trees if they want to save them," he added.

"Any tree ... It can be privately owned, but it's a public resource. That's the irony of the thing."

Rosen said that Ottawa, 20 per cent of whose "forest coverage" was ash, didn't "aggressively challenge" the problem at first - then paid the price.

"That forest cover is lost," he added. "There's some neighbourhoods in Ottawa ... It's a huge difference in what they were to what they are now as far as forest cover goes. It's a bad example."