Preserving ash trees can be expensive, but worthwhile

Niagaraadvance.ca
June 15, 2016
By Penn Coles

The Niagara-on-the-Lake councillor has a large Butler Street property with a private outdoor retreat that offers a combination of sun and shade for relaxing and entertaining. Both the feeling of seclusion and the canopy that screens her back yard are provided by two mature ash trees, one about 115 years old, the other planted about 80 to 90 years ago.

When Disero moved in six years ago, she and her partner, Dan Williams, investigated their options, and discovered it would cost about $1,000 to take the trees down. Leaving them standing, unprotected from the emerald ash borer was not an option - they were so large they created a hazard to keep.

The only other option - the one they chose - was to treat the trees, paying $1,200 every two years, says Disero, with no end in sight.

It's not an inexpensive fix, but the cost of removing the trees and replacing them isn't cheap either, and it will be decades before the replacements would provide the canopy of mature trees, she said.

"I didn't want to cut them down. They're beautiful trees, and I like the shade they give us. But this is a real commitment."

Andrew Cook, from Andrew's Tree and Shrub Care, is one of a handful of arborists qualified to inject a systemic insecticide called TreeAzin to control the beetle, which worked its way from Windsor to Niagara, where it was first noticed in Welland in 2009. It is now destroying ash trees across Ontario.

Once a tree is infected with the beetle, it will die without treatment - there are no natural enemies to it in North America, said Cook, who is treating the trees on Disero's property.

It's estimated by experts that within the next few years, the Asian beetle will have killed the majority of Niagara's ash trees. The cost for municipalities to treat trees on a large scale is prohibitive, says Disero, although some Niagara municipalities are trying to save their older, most significant trees.

In NOTL, an inventory of ash trees was taken in 2014 and the trees were assessed for condition and degree of potential hazard, says a fact sheet posted on the town's website.

The town's 2016 budget included $75,000 for the removal of ash trees and replanting, which is now underway.

Specific trees on Queen Street and at the Jean Melrose Bevan Heritage Tree Walk at the community centre are being treated injected with TreeAzin, the fact sheet said.

The insecticide is injected at the base of the tree, and is drawn up as the tree would draw water. It sterilizes the female borer, explains Cook, and kills off the larvae so that no new eggs are hatched. But it only protects trees that are treated, and only as long as the treatment is continued - it's not a permanent fix.

Disero was a city councillor in the city of Toronto when that city created a plan that recognizes the value to the environment and the savings of tax dollars when trees are protected, she said.

Wayne Wakal, a professor of horticulture at Niagara College, brought 20 students to meet with Cook and Disero at her Butler St. home to teach the students how ash trees can be preserved.

"If you think of their contribution to the environment, you understand their value. They're not just pretty, they're important."

Wakal, who was Cook's instructor at the college, has a passion for preserving trees and teaching students their value to the environment, and points to the Toronto tree bylaw as one that recognizes the value of trees and proactively protects them on private and public property. Toronto is protecting 13,000 ash trees on public property, and is encouraging property owners to treat trees that are still healthy, and remove those that aren't.

NOTL's town council recently approved investigating a tree fund policy, recognizing the value of trees to the environment: they provide shelter and reduce windspeed, thus reducing heat loss from buildings during winter, provide shade in the summer reducing air conditioning costs, and therefore decrease the production of associated air pollution and greenhouse gas emissions, council's request said. Trees also remove air pollutants and store and sequester carbon dioxide, vegetation reduces runoff and improves water quality by absorbing and filtering rainwater - in addition to the aesthetic value and habitat they provide for wildlife.

With the town's tree canopy in decline, council requested town staff to "review the possibility of the creation of a town tree fund that would accept donations from the public for the purpose of planting trees."