A convoy of evacuees from Fort McMurray, Alberta drive past wildfires that are still burning out of control as they leave the city Saturday, May 7, 2016. The increasing frequency of wildfires in Canada’s boreal forest may be permanently changing one of the largest intact ecosystems left on Earth, new research suggests.THE CANADIAN PRESS/Ryan Remiorz

Fewer trees, less undergrowth: Study says wildfires changing boreal forest

Previous studies have found that the look of a forest is set early after a fire

The increasing frequency of wildfires in Canada’s boreal forest may be permanently changing one of the largest intact ecosystems left on Earth, research suggests.

“We feel pretty confident these effects will persist,” said Ellen Whitman, a forest ecologist at Natural Resources Canada and the University of Alberta.

Whitman is a co-author on a recently published paper examining what happens when stands of boreal forest — the huge belt of green that stretches over the northern reaches of most Canadian provinces — are burned over more often as a result of climate change.

She and her colleagues paired up forest areas that had similar climate and soil conditions and had last been burned by the same fire. One half had been previously burned no more than 17 years before, while the other half’s last fire had been at least 30 years ago.

The differences were striking.

The short-interval stands were far more open with fewer trees. Aspens dominated instead of conifers. Growth beneath the trees — shrubs and grasses that cover a normal forest floor — was far less luxuriant with many fewer species. Areas of exposed mineral soil, where all organic material had been burned off, were larger and more common.

They felt completely different.

“You have a landscape where you’re surrounded by short, stunted trees,” Whitman said. “You have a crust of lichen or some sparse grasses. It’s almost like walking through the edge of a prairie where you’re shifting from a grassland into a forest edge.

“At a lot of the long-interval sites, you’ve got quite dense conifers, closer together. You’ve got moss on the ground and flowers and shrubs. It’s more what looks like a young forest.”

The boreal forest has evolved for fire. Many of its tree species need it to germinate.

Normally, fires don’t come around more often than every 30 years and often much longer. The lack of fuel in recently burned stands helps regulate that frequency.

Climate change is breaking those rules, Whitman said.

“We’re experiencing more hot, dry windy days — the main trigger for large fire years. As more years experience more extreme fire weather, (the blazes) are able to overwhelm that resistance that recently burned sites have.”

Nor are the parkland-like areas likely to evolve into a conventional boreal forest. Previous studies have found that the look of a forest is set early after a fire.

“Immediate post-fire condition is an extremely strong predictor of what the stand will look like further down the road,” said Whitman.

Whitman emphasizes that short-interval stands in her research are still small and most stretches of boreal forest burned in recent wildfires are regrowing normally. Wetlands are also less affected by short-interval fires than drier regions.

She said the forestry industry is unlikely to be affected any time soon — although forest-dependent animals such as caribou and songbirds will feel impacts.

And those impacts are growing.

“With a longer fire season, larger fires, more of the landscape burning each year, the likelihood of encountering a recently burned area increases. We’re undergoing a shortening of the fire frequency in the boreal forest.”

READ MORE: Experts say climate change is driving up the risk of wildfires in Canada

Bob Weber, The Canadian Press


Like us on Facebook and follow us on Twitter.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Senior Rainmakers take both games against visiting Brookswood Secondary

Charles Hays sweeps the weekend series against the AAA Langley side

Disrespectful that Horgan won’t meet during northern B.C. tour: hereditary chief

Na’moks said he was frustrated Horgan didn’t meet with the chiefs

Commercial fishing concerns over North Coast marine protected areas

Fishermen of the Northern Shelf Bioregion seek solutions through consultations

BC Green Party leader visits Wet’suwet’en camps at heart of pipeline conflict

Adam Olsen calls for better relationship between Canada and First Nations

Prince Rupert RCMP address Maclean’s report, city’s crime severity index numbers

New online crime reporting system coming to town this year as well

WEB POLL: Are you in favour of LNG exports from the North Coast?

AlaskCAN LNG recently announced their goal of building a $12 billion LNG… Continue reading

ICBC to bring in ranking system for collision, glass repair shops

Change comes after the much-maligned auto insurer has faced criticism for sky-high premiums

‘It was just so fast’: B.C. teen recalls 150-metre fall down Oregon mountain

Surrey’s Gurbaz Singh broke his leg on Mount Hood on Dec. 30

Poll suggests some don’t think Canada should send troops to stop genocide

The findings are being released just before the 75th anniversary of the liberation of Auschwitz

B.C. woman crowned the fastest female marathon runner in Canadian history

Malindi Elmore ran an incredible 2:24:50 at the Houston Marathon

Alberta bulldog breeder ordered to give refund to B.C. buyer due to puppy’s behaviour

Tribunal ruled a verbal agreement to send a new dog superseded the written contract

UPDATED: Man dies in backcountry near Nelson’s Whitewater Ski Resort

The victim was found unresponsive in a tree well Friday

Cariboo Memorial Hospital on the mend after cold weather wreaks havoc

Burst pipes and water leaks cause three different incidents

Most Read