Montreal wants more businesses to plant trees

In April, the City of Montreal announced it wanted to accelerate tree planting by incentivizing business owners to plant trees on their property, offering to foot 50 per cent of the bill, CTV News reports, in an effort to reduce heat islands, improve air quality and help drain rainwater.

Yet McGill Department of Natural Resource Sciences Professor Cynthia Kallenbach told CTV there are better ways to adapt the city to climate change, noting that most of its heat islands are in public places, which are largely already vegetated.

"I'm not sure how much planting trees on private property is going to resolve that issue of lowering the temperature, providing shade, cooling the city during hotter periods of the summer," she said, though she noted there could be other benefits.

"If commercial spaces are maybe changing some of their driveways or pavement or cement to plant trees, that could increase filtration of water. It could provide habitat that otherwise wouldn't be there for increasing biodiversity."

A better environmental strategy, said Kallenbach, would have been to incentivize businesses to plant gardens on their property rather than trees, which she says have a lower maintenance cost and are more effective at combatting ever-increasing flooding due to climate change.

"Rain gardens, deep-rooted plants, grasses that are water-tolerant: those can do a lot for mitigating flood risk," she said. "They also, in some cases, can be very powerful at sequestering carbon out of the atmosphere because a lot of that carbon is stored underground in the roots of grasses."

Not everywhere is a great spot for trees, she said, adding that the best course of action is to have as much variety as possible when greenifying spaces.