Trudeau's tree-planting plan could hurt more than it helps

Prime Minister Justin Trudeau’s campaign vow to plant two billion trees over 10 years likely won't have the desired effect of reducing Canada’s greenhouse gas emissions, say forest experts. And without meticulous planning and careful execution, the plan could make matters worse.

Planting those trees isn’t going to fix the country’s carbon imbalance, says Lori Daniels, forestry professor at the University of British Columbia. “The forests haven’t been sequestering and storing carbon faster than we can emit it since early 2000. We’re 20 years behind.”

Moreover, there’s no guarantee all the trees will survive, given the changing conditions affecting forests, Daniels says. In central British Columbia, for example, a combination of timber harvesting, mountain pine beetle infestation, wildfire and climate change has led to hundreds of thousands of reforested trees dying.

“We need to be very strategic about where we put those two billion trees, what species they are, make sure that we’re not planting them in densities and in ways that when those trees are 20 or 30 years old, they create a massive fire hazard,” Daniels says.

A study led by McMaster University researchers who investigated the 2016 Fort McMurray wildfire found that boreal peatland that had been drained and replanted with black spruce contributed to the fire’s severity. Heavily drained peat and the larger trees that grew on it burned more aggressively than smaller trees in wetter peat.

Daniels notes that forests harvested for timber in B.C. are replanted exclusively with conifers, yet recent research shows that having aspen and other broadleaf trees mixed with needle-leaf trees is essential for moderating wildfire behaviour.

Although record wildfires have ravaged western Canada’s forests in the last few years, there’s no need to replant trees on the burned landscape, says Edward Struzik, a fellow at the Institute for Energy and Environmental Policy at Queen’s University.

“That’s the beauty of a boreal forest: it’s born to burn,” he says. “Fire causes the spruce and pine cones to open and release their seeds.”

Natural regeneration and succession will regrow the forest’s complex ecosystem, Struzik says. “I think we’re best left creating the conditions for Mother Nature to grow our trees, rather than us going out there and creating plantations all over the place.”

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