New report shows Canada’s trees in growing trouble

Almost one-quarter of tree species now at risk

Almost one in four Canadian tree species is now at risk in Canada according to a new assessment by the Wildlife Conservation Society Canada as part of its ongoing SHAPE of Nature initiative to track the health of Canada’s wildlife and wild places.

View the report

“For a country so closely identified with forests, this is alarming news,” says Dan Kraus who led the assessment for Wildlife Conservation Society Canada using data from NatureServe Canada and the International Union for Conservation of Nature Red List of Threatened Species.

Threats to trees ranging from introduced pests and diseases to the rapidly growing impacts of climate change and land development are rapidly reshaping the diversity of tree species in Canada’s forests. Of the 57 tree species at risk in Canada, half are also considered to be of global conservation concern.

Whether it is white ash in urban forests that are declining because of the introduced emerald ash borer, the loss of forests in southern Ontario that once supported black gum and cucumber tree, or high-alpine Yukon lodgepole and whitebark pine that are being squeezed out of the landscape by climate change, threats to trees are widespread and growing.

“Trees are the foundation of forests and many other ecosystems, providing food, shelter and nesting or denning sites for wildlife. Losing the diversity of trees is devastating for the ecosystems and the species that depend on them. In less than one generation we’re seeing the richness and diversity of Canada’s trees slipping away,” Kraus explains.

“We released these results on the International Day of Forests to help raise awareness about the plight of Canada’s trees,” Kraus points out. “There are still many actions we can all take to help protect the diversity of Canada’s trees – from increasing the diversity of species in tree planting projects to stopping the spread of invasive species to identifying Key Biodiversity Areas that harbor our most imperiled trees.”

Some of these at risk trees exist in only small pockets of Canada, such as Pacific Bayberry or Murray's Birch. With 234 species of trees, Canada has rich arboreal diversity but this diversity has taken an especially hard hit in places like southern Ontario and southern BC where forest clearing has left only tattered patches of woodlands. These are also some of the most “tree diverse” regions of the country.

“Trees are important to people in a multitude of ways beyond just being a source of products like maple syrup or lumber,” Kraus points out. “They cool our urban areas, clean our air, filter our water and stabilize our soils. Just as importantly, being in the presence of trees makes us healthier both physically and mentally as a number of studies have now shown.”

“For a country with a maple leaf on its flag, we have to do a better job of standing by our trees,” Kraus concludes.


How can we better protect Canada’s trees?

There are lots of ways we can help trees.

  • Identifying and recognizing the habitats of rare trees and supporting conservation and stewardship efforts in these places including through the Key Biodiversity Areas program.

  • Replanting a wide variety of native species can help us build back beneficial tree cover everywhere from urban centres to farms.

  • Supporting work to collect genetic material from individual trees that are more resistant to pests and pathogens can set the stage for reintroductions of species that are currently being lost, like ash or American chestnut.

  • And finally, we need to start thinking about how to help trees adapt to climate change, including by planting species outside their existing ranges and protecting climate refugia areas.

A list of specific measures is included in the assessment.


Read more about the State of Canada’s Trees.

Key Biodiversity Areas

Key Biodiversity Areas

Canada's critical places for nature

SHAPE of Nature

SHAPE of Nature

An accessible and comprehensive clearinghouse that shares the status and trends of biodiversity conservation across Canada.