Why a tree’s past may hold the answer to future forest recovery efforts

Date published: 2023-10-23 10:00:00

2023 was a summer to remember, but for all the wrong reasons. It was the hottest ever recorded globally and the worst for wildfires in Canadian history. Wildfires ravaged Italy, Portugal and Spain, and Greece suffered the most devastating wildfire ever in the European Union. The wildfire season in Canada was catastrophic. By the end of September, nearly 18 million hectares—an area larger than Greece—were consumed by fire. This was the most land burned in a single wildfire season, more than seven times the yearly average and a 647% increase over the 10-year average.

With states of emergency, evacuation orders and heavy smoke blanketing most of the country from coast-to-coast-to-coast, Canadians watched the destruction unfold. Few more closely than Canada Research Chair in Fire Ecology Dr. Jill Harvey.

“I live in Kamloops, British Columbia, so we had wildfires burning not far away from our home,” says Harvey, who is an assistant professor in the Department of Natural Resource Science at Thompson Rivers University.

“While we were dealing with heavy smoke, I think what affected me the most was seeing the faces and hearing the stories of my graduate and many undergraduate students who are firefighters. Hearing the impact the wildfires had on the landscape, and on them personally and professionally, it’s heartbreaking,” Harvey adds.

The climate connection to forest recovery

Harvey says while this season’s wildfires were historic, scientists like her are not surprised as they’ve been monitoring a disturbing trend for years.

“If we look at British Columbia, four of the biggest wildfire years on record have been in the last seven years. They caused more damage than the previous 50 years combined,” Harvey explains. “The connection between climate change and wildfire is proven. We know that as the climate warms and dries we will start to see more wildfires on the landscape.”

Over the last 100 years, Harvey says wildfire was mostly removed from the landscape through fire suppression activities. It means much of Canada's forests have overgrown, the density now acting as “fuel” on the land when a fire does ignite.

“Forests are incredibly resilient, and some fire is really important to forest ecosystems,” Harvey adds. “But when we see bigger areas impacted by high severity wildfires and more often, we wonder what the impact will be going forward. Will forests have time to recover before the next fire? Will we lose forests? Will the characteristics of forests change over time?”

A ring of knowledge

As an ecologist, a person who studies the connection between living things and their environment, and a dendrochronologist, an expert on the study of tree rings to determine the chronological order of past events, Harvey believes fire-struck forests have a story to tell.

“If a fire scars a tree and it doesn’t kill it, it leaves a record of those different fire events in the tree rings throughout the duration of the tree’s lifespan,” explains Harvey. “In interior BC, trees can be 400 years old, and we can use those tree-ring records to understand more about past wildfires.”

Harvey and her team of graduate and undergraduate students are in the process of setting up permanent research sites in forest areas that recently burned in interior British Columbia. At each site, they will carefully measure fire severity. The scientists will then return every two years to examine how the forest is recovering.

“If we’re able to have some baseline ecological knowledge and understand areas that may be vulnerable to forest regeneration failure, we can then use that information to inform forest management strategies in the future,” adds Harvey. “In the sphere of science, we realize this will take some time to get results, but we know it’s important to gain long-term insights into how forests recover.”

Policy, prevention and preparedness

Harvey believes policy-makers must be creative in fire management and mitigation policies. That may include investing in advanced weather prediction technology, planting trees to support forest recovery in hard-hit areas, and focusing fire suppression efforts in areas near communities and in forests with high-value timber. Harvey also says solutions must be inclusive and include diverse perspectives.

“In the past, Indigenous Peoples were stewards of the land and they used wildfire and cultural burning as a tool to manage resources. We need to learn from these practices,” says Harvey, who is currently working with several Indigenous communities on various research projects, from how to better understand historical fire patterns to the effects severe wildfires have on the caribou habitat.

Harvey is proud of her research and honoured to be training the next generation of wildfire scientists.

“I think we’re at a flex point now where we have to make some changes on how we view wildfires,” notes Harvey. “We have to learn to coexist with wildfire—it’s not going anywhere. The research we are doing will be an important piece to understand historical wildfires, the ecological effects and how we can be better prepared in the future.”

Want to learn more?

Go here to learn more about Jill Harvey and her innovative forest recovery research. For an in-depth look at the historic 2023 wildfire season and the current fire conditions across the country, visit the Canadian Wildland Fire Information System (CWFIS).