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

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

There are only two EV-charging stations in Campbell Heights, one in Clayton, and one in Cloverdale—with an additional station currently under construction, according to plugshare.com The federal government recently announced Surrey is getting 40 more charging stations with construction to begin immediately. (Image via plugshare.com)
Chamber director hopes Cloverdale area not forgotten when new charging stations installed

New charging stations need be built in Cloverdale, Clayton, and Campbell Heights: Scott Wheatley

The SACH Community Hub team, from left to right: Upkar Singh Tatlay, Gary Thandi, Allysha Ram, Jassy Pandher, Harman Pander. (Submitted photo)
There’s help for South Asian men wrestling with drug addiction in Surrey

South Asian deaths related to toxic drugs increased by 255 per cent between 2015 and 2018

Surrey residential construction. (File photo: Tom Zytaruk)
Surrey councillor says city needs more accessible housing

Linda Annis expected to introduce notice of motion to that end at tonight’s council meeting

RCMP Isp. Benoit Maure (top right) has written a book, Leading at the Edge, which details Canadian peacekeeping missions, including his own 1999 mission in Guatemala (bottom right). (Contributed photos)
Longtime RCMP officer pens book on Canadian peacekeeping efforts

RCMP Isp. Benoit Maure’s new book, Leading at the Edge, features stories from 10 missions

Crews with Discovery Channel film as an Aggressive Towing driver moves a Grumman S2F Tracker aircraft around a 90-degree turn from its compound and onto the road on Saturday, Jan. 23, 2021. It was the “most difficult” part of the move for the airplane, one organizer said. (Jenna Hauck/ Chilliwack Progress)
VIDEO: Vintage military plane gets towed from Chilliwack to Greater Victoria

Grumman CP-121 Tracker’s eventual home the British Columbia Aviation Museum on Vancouver Island

Provincial health officer Dr. Bonnie Henry talk about the next steps in B.C.’s COVID-19 Immunization Plan during a press conference at Legislature in Victoria, B.C., on Friday, January 22, 2021. Two more cases of the COVID-19 strain first identified in South Africa have been diagnosed in British Columbia, bringing the total to three as of Jan. 16.THE CANADIAN PRESS/Chad Hipolito
B.C. now has three cases of South African COVID-19 variant, six of U.K. strain

Both variants are thought to spread faster than earlier strains

Rodney and Ekaterina Baker in an undated photo from social media. The couple has been ticketed and charged under the Yukon’s <em>Civil Emergency Measures Act</em> for breaking isolation requirements in order to sneak into a vaccine clinic and receive Moderna vaccine doses in Beaver Creek. (Facebook/Submitted)
Great Canadian Gaming CEO resigns after being accused of sneaking into Yukon for vaccine

Rod Baker and Ekaterina Baker were charged with two CEMA violations each

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Police discovered a makeshift nightclub in a Vancouver apartment on Jan. 23, 2021, and say it wasn’t the first time this month officers have been called to the unit over social gathering concerns. (Phil McLachlan - Capital News)
Doorman of makeshift ‘booze-can’ in Vancouver apartment fined; police look to court order

This marks the fourth complaint about social gatherings inside the apartment in January

A Kelowna couple welcomed their Nooner baby in December. (Flytographer)
Kelowna couple welcomes baby girl from Hotel Zed Nooner campaign

Nicole and Alex will now have 18 years of free stays at the hotel

The Abbotsford Tulip Festival is permanently closing, with plans to eventually set up in Armstrong, B.C. (Abbotsford News file photo)
Abbotsford Tulip Festival is closing, with plans to rebloom in Armstrong

Event organizer says pandemic and sale of land were factors in decision

Kyrell Sopotyk was drafted by the Kamloops Blazers in 2016 and played two seasons with the Western Hockey League club. (Photograph By ALLEN DOUGLAS/KTW)
Kamloops Blazer paralyzed in snowboarding accident sparks fundraiser for family

As of Jan. 24, more than $68,000 had been raised to help Kamloops Blazers’ forward Kyrell Sopotyk

Most Read