This article is more than 9 months old

This article is more than 9 months old

Canada’s logging industry has a larger and more damaging impact on forest health than previously thought, a new report has found, casting doubt on the sustainability of forestry management in the country.

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The findings also raise questions about Canada’s ability to make good on its international climate commitments, which partly rely on forests for carbon sequestration.

In a report released on Wednesday, the Toronto-based conservation group Wildlands League found that “logging scars” – the vestigial remains of roads, landings and turnoffs meant to accommodate heavy machinery – suppress forest regeneration. Because the dirt roads are so heavily compacted, seedlings have little chance of successfully repopulating the area.

Using drones to survey the 27 sites in northern Ontario, Trevor Hesselink, a land-use planner and former forestry policy analyst, found that the scars made up anywhere from 10% to nearly 25% of the areas where forests had once been logged.

“The extent of the scarring, and getting on the ground to see the longevity of the suppression effect, surprised me the most,” Hesselink told the Guardian.

Wildlands estimates that nearly 650,000 hectares of forest in Ontario – eight times the area of New York City – have been lost in last three decades due to scarring.

While the province makes up a small part of the country’s overall logging industry, Hesselink and his team believe the long-term damage to forests is probably more common than many realize. The practice of “full tree harvest” – where entire trees are cut down and moved to a landing area to be processed – is also used in western provinces, where the logging industry is more widespread.

Facebook Twitter Pinterest ‘The extent of the scarring … surprised me the most,’ said Trevor Hesselink, a land-use planner and former forestry policy analyst. Photograph: Wildlands League

“We’ve been told over and over that Canada has a near-zero deforestation rate,” said Janet Sumner, Wildlands League’s executive director. “But it wasn’t what we were seeing in the bush. So we took a closer look. And now we know.”

Canada’s forests have become central to the Liberal goverment’s pledge to fight the climate crisis. As part of his re-election campaign, the prime minister, Justin Trudeau, promised to plant 2bn trees in the next decade.

Hesselink’s findings also call into question Canada’s calculations of carbon sequestration from its forests. The lost carbon storage could be as high as 41 megatons by 2030 – or an entire year’s worth of passenger vehicle emissions in Canada.

“As long as these logging scars are suppressing the natural renewal of forest, they’re forgoing carbon that could removed from the atmosphere,” said Hesselink.