The shift reflects how a key Canadian resource sector has declined due to U.S. duties and other challenges, including wildfires, land-use regulation and insect infestations.

As if things weren’t volatile enough in the lumber market, a Canada-U.S. trade tussle will make things worse.

High lumber prices are back, even as the industry steps into what is normally a seasonal lull.

Lumber futures rose the most in more than a year on concern that wildfires in western Canada will reduce supply and spur more curtailments at sawmills.