As disease and pests threaten the future of Winnipeg's tree canopy, Mayor Brian Bowman is asking Winnipeggers — each and every one of them — to get involved in saving one of the city's defining features.

The mayor issued a challenge to the city's residents on Thursday morning: plant one million trees over the next 20 years, or by the time Winnipeg's population is expected to crack the seven-digit mark.

The city's population was 753,700 in 2018, according to City of Winnipeg data.

The mayor said threats like the emerald ash borer beetle and Dutch elm disease pose a serious risk to Winnipeg's trees — together, they're expected to have a devastating effect on Winnipeg's public tree canopy over the next century, affecting up to two-thirds of the city's trees.

"Much of our urban tree canopy is under threat," Bowman told CBC News on Thursday. "As we grow to a million people, our tree canopy — if we progress on the current path — is going to be decimated."

Bowman said he has learned more about threats facing the city's trees in recent years, and felt compelled to take action.

"If you just imagine looking at our city and imagining two-thirds of the current trees gone, that's not a city we want to live in," he said.

"This is an acknowledgement that we need to do more."

$1M donation to kick off challenge

Bowman said the initiative will challenge individuals, non-profits and private businesses to help by planting trees on their property, volunteering to plant trees in other spaces or donating to Tree Canada, a national tree-planting charity that will support efforts to plant more trees in Winnipeg.

The charity also received a $1-million donation from the Canadian National Railway to kick start the One Million Tree Challenge.

The emerald ash borer is the latest threat to Winnipeg's tree canopy. (Holly Caruk/CBC)

"We are proud to be a part of this community and to make this investment in Winnipeg, home of thousands of CN employees, retirees, and their families," said Sean Finn, CN executive vice-president, in a news release.

CN has worked with Tree Canada to plant trees across the country, he said.

"We encourage other companies to join us in participating in this challenge."

Mayor Bowman said the new initiative will be on top of the city's existing tree placement program, and whether the city meets the million-tree goal will depend on how much support the initiative receives from the community.

"This won't be developed and ready tomorrow," he said. "My role in this is to set the vision and provide the leadership to encourage the community to come together and for us to work together."

He noted the benefits of planting trees range from having a positive effect on the environment to increasing property values.