Emerald ash borer reshaping streetscapes

Therecord.com
April 18, 2017
By Catherine Thompson

The destructive emerald ash borer is reshaping streetscapes across Waterloo Region, as the three cities continue with plans to remove most of the ash trees lining their streets.

The pest beetle, first discovered in North America in 2002, kills virtually every tree it infests. Its presence was confirmed in Cambridge and Kitchener in 2010 on either side of Highway 401 at Homer Watson Boulevard, and in Waterloo in 2011. It multiplies quickly and was introduced to the U.S. from Asia via wood cargo crates.

Waterloo's treescape is the most affected among local cities. About 17 per cent - one in six - of all the trees along Waterloo streets are ash trees. Most of those will be cut down, though the city is injecting the oldest and largest trees, in areas such as Waterloo Park and along Dick and Peppler streets to try and save them. The treatment is costly, though, since trees have to be injected twice in three years and each injection costs $175 or more per tree.

The pest's impact on the streetscape can be devastating, especially because parts of the city, such as Westvale, had streets planted almost exclusively with ash trees, said Tim Wolfe, Waterloo's manager of forestry.

"It's going from a street that had a canopy almost reaching on both sides of the street, to having small subdivision trees," Wolfe said. "It's like starting from scratch all over again."

The impact is less severe in Cambridge, where like Kitchener ash trees make up only about seven or eight per cent of all the street trees.

"Overall, seven per cent is relatively small compared to some cities. But when you add up the numbers — 4,000 street trees and 8,000 trees in city parks and woodlots, it's a lot. And it's not very evenly distributed across the city, so in some areas it's drastic," said Brian Geerts, Cambridge's manager of forestry and horticulture.

Most of the ash trees in the three cities will be cut down, or have been already. In Kitchener, the last of the 5,000 ash trees slated to be cut down will be gone by the end of April.

Waterloo began cutting down ash trees in 2014 and has so far cut down about a quarter of them in a $3.6 million program that runs to 2024.

Cambridge has budgeted about $7.5 million over 10 years to deal with the pest, and has removed about half of all ash trees on city streets. Removal is expected to continue until 2020.

But budget constraints mean Cambridge is replanting more slowly than the other two cities. It has cut down about 3,500 ash trees, but so far only replaced 300 with new trees. In most cases, it will be three to four years before the city replants.

Kitchener replants within 18- 24 months, while Waterloo aims to get a new tree in within a year of removal. All three cities are replanting with a wide array of native and non-native trees, to make sure no street is decimated if a future pest hits.

"It's a tough time right now," admits Geerts. "People are really feeling the loss of the trees."

Tree removal is focused along streets, in parks and in natural areas where the ash trees are close to the property line or to trails, where a diseased tree could cause problems if it fell over.

Kitchener is protecting another 1,000 of the largest and healthiest ash trees by injecting them, at a cost of about $80,000 a year. Cambridge hasn't done widespread injecting, protecting only a handful of trees in high-profile spots.

"There is no plan to stop injecting the trees for the foreseeable future," said Lindsay Button, a tree specialist with the City of Kitchener, in an email. "The injection program is still recognized as a cost-effective way for the municipality to manage tree removal costs, while at the same time preserving a part of the ash tree canopy which is providing important benefits to the community."

There is a bit of a silver lining in the devastation caused by the beetle, said Adam Buitendyk, a forest technologist with Kitchener.

"It did bring attention to the importance of trees and the urban forest to people who may not have considered that before," he said.

Kitchener, like Cambridge, is working on an urban forest strategy and greater awareness about the benefits trees bring will help those efforts.

"If we want to have a sustainable urban forest in the future, we have to manage it now," Buitendyk said.