Fewer trees with Dutch elm disease tagged to be cut down in Winnipeg
Regulations banning the pruning of elm trees until July 31 in effect
City workers in Winnipeg will take down 4,700 elm trees this spring, after being marked as infected with Dutch elm disease.
The good news is the number of trees being cut down this spring has declined by about 1,000 trees compared to last year.
When CBC's Up to Speed host, Ismaila Alfa asked 'why?', Martha Barwinsky, a city forester with the City of Winnipeg, said quite bluntly: "We don't really know."
Barwinsky said that there was speculation that last year's frigid winter had managed to kill off a number of Elm bark beetles — but there is no way to confirm that theory.
"We'll always have Dutch elm disease here. We will never eradicate it," Barwinsky said Friday.
"It's a very difficult disease to eradicate, you essentially cannot eradicate it because it is so complex. How we have proven that you can successfully manage it and maintain a very valuable elm canopy like we have in Winnipeg,"
On top of the axing of infected elms city crews are also replanting trees around the city, including maples, ash, lindons and more elm trees.
"It is a very valuable tree in the urban forest and that is why we are still planting it. And we know that we can manage the disease."
Some of the elms being planted are different varieties of the tree, including the Japanese Elm that is resistant to dutch elm and some experimentation with the Prairie Expedition American Elm trees which were developed in the United States. A Winnipeg winter will determine whether they are hardy enough to survive here.
"Due to our climactic conditions we have very few species to choose from," Barwinsky explained that the replanting of elms is incredibly important to maintaining the urban forest in Winnipeg. Without them, "it would have a significant impact on our quality of life here."
Managing Dutch elm
The city manages Dutch elm disease through surveillance, which involves annual identification of the disease and then the removal of those tree, and it also involves controlling the Elm Bark Beetle.
"We have a better pruning cycle than we had about 10 years ago, so it is an integrated program," Barwinsky said.
Barwinsky went on to say no other Canadian community was battling the tree disease 'at the same level' that city crews are in Winnipeg.
Winnipeggers are reminded that pruning of elm trees is prohibited between April 1 and July 31, as is storing elm fire wood, which provides a place for the beetles to hide.