Too late to stop ash borer spead

The City of Sherbrooke is preparing to change the rules in the battle against the Emerald Ash Borer based on information indicating that the invasive insect has been present in the region much longer than previously thought. In light of the new information, the requirements on residents that were originally quite strict in order to control the spread of the insect have been relaxed in the name of preserving forest cover.

“Observations this summer allowed us to determine that we are actually in year five of infestation,” said Roger-pier Mercier Division chief for parks and green spaces at Monday night’s city council meeting, explaining that although the first infested tree discovered last October gave the impression that the infestation was only 2-3 years old, a tree found in Ernest Bergeron Park in Brompton showed much older scarring.

Mercier explained that the rapid-cut approach previously endorsed by the city was meant to help keep the insect, which has a limited range, from spreading to other nearby trees. With infestations having been present and undetected in the city for as much as five years, however, the spread of the ash borer is already too extensive, meaning that immediately cutting down healthy trees in a perimeter around infestations will just result in a rapid deforestation of the city.

“At the time the strategy was good, but now it needs to be reviewed,” the division chief said. “Ash owners can now choose to cut now or later on.”

Asked whether the city expects frustration from Ash owners who have already spent money on cutting or treatments under the existing rules, Mercier stressed the point that those were not wasted dollars. Speaking of the insect as an inevitability, the division chief said that no ash tree in the city is safe.

“You have to realize that all of the ash trees will need to be cut down at some point or another,” he said.

Under the new rules, owners of ash trees will have the choice of treating their tree once every two years in order to help protect it against the insect, waiting until a tree is dead to cut it down, or cutting down a healthy tree and planting a new one in its place.

“Sherbrooke is known as a city of nature,” said Sherbrooke Environment Committee president Karine Godbout. “We need to avoid cutting down all of the ash trees in a short period of time in order to better ensure replacement of the tree cover.”

The city estimates that there are 2,500 ash trees on public land in the city and as many as 12,500 on private properties. Information has already been sent out to all those residents who have reported having an ash on their property using the city’s online tool sherbrooke.ca/agrile, and it is still possible to report new trees.

The new rules are set to be approved on October 1 and will come into effect on October 4.