Smoke not the only long-range effect of British Columbia wildfires
Smoke isn’t the only way wildfires affect people and places far from the flames.
Researchers are studying how blackened forests affect ecosystems and water quality far downstream just as hundreds of blazes in British Columbia are darkening skies as far east as Manitoba.
“Fires are particularly hard on water,” said Monica Emelko, a water treatment engineer at the University of Waterloo and a member of the Southern Rockies Watershed Project.
“If the intensity is there and enough of the watershed is burned, you can have a very significant impact on the water supply and that impact can be long-lasting.”
The project began more than 10 years ago after southern Alberta’s 2003 Lost Creek fire. Its work has proven so valuable that the team recently received about $9 million in grants to keep studying how changes in forested areas affect water.
Fires and forests have always gone together. But that relationship began to change around the turn of the century.
“Fire managers started to see wildfire behaviour that was at the extreme end or beyond anything that had been previously observed,” said Uldis Silins, a University of Alberta hydrologist and project member.
The intensity and speed of fires ramped up. Blazes that used to calm overnight kept raging. At Lost Creek, firefighters reported walls of flame 150 metres high rolling through trees at 2 a.m.
A 2016 published paper found the effects of that fire were visible in rivers and streams more than a decade later.
Runoff began earlier and was faster, increasing erosion and creating drier forests.
Nutrients such as phosphorus were up to 19 times greater — good for aquatic bugs but also for algae.
“Some of these streams became choked with algae,” Silins said. “We’ve seen lasting and pretty profound impacts on water quality and aquatic ecology.”