Borer-infested ash trees being chopped down in Etobicoke’s Centennial Park
City contracts to remove nearly 450 trees from woodlot

Etobicoke Guardian
February 6, 2014
By Tamara Shephard

If a tree falls in the forest does anybody hear?

The answer is likely yes, if you live near or regularly visit what has been called Etobicoke’s “crown jewel” Centennial Park.

The mostly ash tree woodlot near the park’s ski chalet is the subject of forest management by the city’s urban forestry department.

Translation — city officials have hired a contractor to remove 92 fairly large, and approximately 350 moderate-sized ash trees marked with blue paint, decimated and dead or drying from the emerald ash borer.

“That’s a fairly significant impact,” Jennifer Gibb, one of two natural resource specialists with the city’s urban forestry department, said in an interview. “This little bug has definitely impacted our trees more than the Asian Long-Horned Beetle,” which both city and federal officials reported last year had been eradicated.

Etobicoke’s borer-infested ash trees are among Toronto’s 860,000 ash trees affected by the borer, an Asian beetle made its way to Toronto from Detroit, Mich. in 2002, leaving dead and dying ash trees behind.

The city detected the first infestation in 2007, then in further surveys in 2008-09.

A city-hired contractor will remove the trees in a manner similar to logging. The dense forest won’t allow for conventional removal, which is climbing the trees and cutting them down branch-by-branch. Instead, a machine called a skidder will fell the trees, the best option Gibb said, to deal with the large volume of trees in a way that will cause the least damage to the woodlot.

The felled ash wood will be harvested into logs to be sold, which helps to lower the cost, she said.

Weather permitting, the removal could begin next week. If not, it will likely happen in late February, Gibb reported.

Another contractor has already removed the underbrush of buckthorn and honeysuckle.

The forestry management strategy is designed to both protect residents from potentially falling dead “hazard” trees, and to help regenerate the woodlot with both new hickory, oak and maple trees and an opened canopy that will allow ash seedlings to better take root.

Although, the prevalence of the emerald ash borer makes it unlikely those ash seedlings will grow to maturity, Gibb said.

People will likely be shocked by what they see, she suggested.

“When people hear about it, they don’t necessarily understand what will happen until they see it,” she said. “In the winter, you don’t see dead trees. All the trees look the same...In spring, those trees will be gone and there will be brush left.”

Etobicoke was hit later, and less dramatically, by the borer than the city’s east end, where the first borer infestations were found in 2007. Etobicoke also has fewer ash trees than other parts of Toronto.

The city’s tree removal emerald ash borer management strategy has been contained in Etobicoke to the woodlot and manicured, well-traveled areas in Centennial Park, as well as Bloordale Park.

“We’re trying to do the removal in a natural way leaving some of the brush behind to decompose and undertaking a fairly aggressive replanting program to reintroduce a high diversity of tree species,” Gibb said.

Studies indicate most of Toronto’s ash trees will die by 2017.

However, city forestry officials have made some headway in saving the ash by injecting trees with TreeAzin, a biological insecticide that disrupts the beetle’s life cycle.

“(TreeAzin) is not the 100 per cent perfect solution,” Gibb acknowledged. “But we’re trying to keep some trees alive as long as possible. Those one or two years contribute to a healthy tree canopy, and provide oxygen. If all the trees died, we’d have to scramble to take them all down. I’m really hopeful they’ll last awhile, but that won’t necessarily happen.

“The infestation is so widespread, it just wasn’t possible to quarantine it. At this point, most ash trees are dying or dead except for the ones that have been injected.”

Ash trees can grow up to 30 metres in height, and are a common species in the urban forest.

Homeowners are urged to learn whether or not they have ash trees on their property, and if so, to check their tree’s health.

A drove of woodpeckers visiting a tree isn’t scientific, but it can suggest the bird is eating borer larvae. Other signs include D-shaped borer exit holes visible in tree bark.

If a resident’s ash tree looks in severe decline, Gibb suggests calling an arborist.

The Toronto non-profit LEAF (Local Enhancement and Appreciation of Forests) can provide Toronto residents with suggestions about replanting other tree species, and also offers residents subsidized backyard tree planting.

The emerald ash borer has been so destructive, the jury is out on the efficacy of injecting TreeAzin into ash trees as a measure to protect the species in Toronto, Gibb said.

“There is a lot of debate in the literature about how long you can keep injecting a tree, whether it’s worth injecting if your neighbours aren’t and the borer is in your neighbourhood,” she said. “I don’t have an answer to that. It comes down to the homeowner’s personal choice. Some hope if they wait long enough (to act) the beetle may be gone. I don’t know about that.”

For more City of Toronto information about the Emerald Ash Borer, visit bit.ly/1fIckwS