Oshawa tackling emerald ash borer damage to Second Marsh, naturalized areas
Second Marsh nature trail closed due to risk of falling trees

durhamregion.com
Feb. 1, 2017
By Reka Szekely

It’s going to take Oshawa city staff three to five years to address the damage wrought by the emerald ash borer (EAB), a destructive insect that has killed more than 90 per cent of ash trees in some areas of the city.

So far, city staff have focused on public safety, removing diseased trees from boulevards and from parks, but works department staff say there is a great deal of work to do in naturalized areas of the city.

“This is going to be ongoing for the next three to five years for sure, and it might go on beyond that because we’re just starting on our open spaces,” explains Glenn Simmonds, director of operations for Oshawa.

In January, city staff and contractors began tree removal in two naturalized areas: at the Second Marsh off Colonel Sam Drive and in a woodlot on the Oshawa airport lands.

The city was forced to close a nature trail in the Second Marsh in the fall in the Ghost Bush Road area just west of General Motors headquarters.

In that area, 95 per cent of the ash trees have been infested by EAB and there’s a danger of falling trees and branches.

“They’re virtually standing dead and some of them are in very poor health, so what we’ve done is closed that area off,” explains Dru Chillingworth, Oshawa’s manager of park operations.

That portion of the trail is closed indefinitely as the city works with its partners, including Friends of the Second Marsh and Ducks Unlimited, to plan future restoration work.

Meanwhile, crews are cutting back trees about 30 metres from the road along Colonel Sam Drive as well.

“We’re clearing back all of the dead ash so that if anything falls, it doesn’t come back on the roadway,” said Chillingworth. Work at the airport woodlot is expected to take six weeks and residents are asked to stay back while crews are there.

Emerald ash borer was first confirmed in Oshawa in 2011. At the time, city staff estimated there were thousands of ash trees in Oshawa including 3,117 street trees, roughly 3,500 in parks and 227,000 in woodlots, valley lands and open spaces.

Simmonds explains that the ice storm in 2013 exacerbated the problem. The ash trees already damaged by the insect were hard hit.

In naturalized areas, Chillingworth said most of the downed trees will be left behind and stumps will be cut to about 10 feet to allow new natural habitats to form.

Simmonds said the final price tag for dealing with the EAB is expected to be in the millions. That includes the removal of dead trees, new plantings and the treatment of some trees with TreeAzin, which has been about 75 per cent successful in preserving trees from the insect.

TreeAzin treatments have been focused in popular park areas and Simmonds said it wouldn’t be feasible to try to preserve the trees in naturalized areas and open spaces.

The city’s resources are finite and in order to deal with EAB, the works department has had to shift resources from its integrated pest management program on playing fields.