Saskatoon scenery could change due to Dutch elm disease, expert says

Dutch elm strikes Saskatoon WATCH: As Keenan Sorokan explains, the city's urban forest is under threat.

An expert says the Dutch elm disease infection in Saskatoon could leave a lasting mark on the city.

The city has identified Dutch elm disease in a tree on Central Avenue, which will lead to the destruction of the infected tree and 30 others nearby to prevent the spread of the tree-killing fungus.

"It’s heartbreaking, but at the same time, you kind of have to cut the foot off to save the leg,” David Kearns with Kearnsy Consulting and Educational Services said.

“We’re seeing an old population of elm trees all over the city that took hundreds of years to grow dropping like flies now,” he said.

Elm bark beetles are attracted to dead wood on a tree, which is how the disease is spread.

Kearns says trees that are stressed release kairomones, which is like a signal telling bark beetles the tree is in poor health.

Years of drought and extreme weather have weakened elm trees in the area, Kearns told CTV News. This has left them more susceptible to disease, he said.

“The elm bark beetles, which are responsible for moving this disease from one tree to another, their movement becomes more pronounced.”

The first case of Dutch elm disease was discovered in Saskatoon in 2015. More cases showed up in 2020 and 2021.

In July, the city found Dutch elm disease in a tree in Pleasant Hill and two in Sutherland.

The city is reminding people not to bring elm firewood into Saskatoon. Rather, it should be taken to the landfill immediately and not stored for any period of time.

"Regretfully, we will have to remove over 30 elm trees, but this is in a shelterbelt area that is mixed with ash trees and caraganas,” the city said in a news release.

“The aesthetic impact won't be as great as if these were removals along Spadina Crescent or University Drive for example."

The city also said that staff will be searching for stored elm wood in the area to prevent the spread of the disease.