Burn in central Yukon, Hilary Cooke / WCS Canada
Burn in central Yukon © Hilary Cooke / WCS Canada

After burn: The new face of fire puts wildlife on the hot seat


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Justina Ray
President & Senior Scientist

Hilary Cooke
Co-Director, Northern Boreal Mountains Program

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Caribou Boreal

Published

2023-11-01

How Canada’s wildlife is struggling to cope with the human-induced forcings of climate change

Read this story in Canadian Geographic.

Fire, fire everywhere. That’s certainly what it felt like this summer as wildfires burned a record area of forested land across Canada, fueled by drought and abnormally high temperatures. According to one calculation, the area burned in Canada during the 2023 summer season was greater than half the countries in the world, making it the most destructive wildfire season ever recorded.

As the largest forested habitat in the world, the boreal forest ecosystem has evolved with a natural cycle of fire and regrowth. Historically, wildfires in the boreal have been vital to maintaining its diversity of habitats and wildlife by creating a patchwork of new and old growth areas spread across a massive region, covering almost 60 per cent of Canada.

Not only have boreal plants and animals learned to “live” with fire, but many species have evolved to benefit from fire. Tree species like black spruce and jack pine require fire to regenerate. Pyrophilous – fire-loving – beetles rapidly move into fire-killed trees, followed quickly by burn-specialist woodpeckers that feast on the beetle buffet and excavate nest cavities in dead trees. Fast-growing plants and shrubs provide forage for species like moose and hares before eventually giving way to a regenerating forest. And the cycle continues.

But things are changing – fast. Hotter, drier conditions driven by a climate that is changing much faster at northern latitudes than in southern areas have set the stage for more frequent and intense burns across the boreal region. Well-honed wildlife strategies for living with fire, whether sheltering in water or wetlands or racing to escape the flames, are being tested like never before.

How animals survive big fire seasons depends on more significant human-driven landscape factors. Animals fleeing from fast-moving flames may have to contend with obstacles like highways or roads while already under stress. Meanwhile, climate-driven droughts and hydro dams can leave downstream areas too shallow to provide refuge for fish, turtles or other animals in the event of a fire.

Not only do wildlife need to adapt in real-time to super-charged fire seasons, but they may also need to adapt to very different conditions afterwards. More intense fires have more severe outcomes, not just burning the woody parts of the forest but also burning through organic layers of soils and peatlands while potentially destroying seed sources needed for regenerating forests. More frequent fires mean forests don’t have a chance to regrow to mature and old growth stages before burning again. Combined with hotter and drier growing conditions, the increase in fires puts boreal ecosystems on a new trajectory, with deciduous replacing coniferous forests across the boreal region.

Even though boreal species are well accustomed to fire, these changes present new challenges. Boreal caribou, for example, need older forests that contain lichen food sources that they rely on, particularly in winter. It often takes more than 40 years for a forest stand to replenish its lichen. In the meantime, these areas are much less attractive to caribou. As larger areas experience more frequent and severe burns, species that rely on mature forests will be left with fewer options for places to go.

Even burn specialists like American three-toed and black-backed woodpeckers may find the new fire regime different from their liking. WCS Canada scientists studying bird use of burned forests point out that if forests burn too frequently, trees will never grow big enough to house the excavated cavity required for nesting by these woodpeckers.

Caribou, in turn, require large, intact landscapes not only for food but as a refuge from predators. It is already a problem when forests are divided and fragmented by resource roads, and old forests are extensively logged or cleared for mining oil and gas or other development. Adding a more frequent and severe fire footprint to that equation limits options for caribou to move around and find preferred areas to feed and give birth. And that’s not good news for a species already considered at-risk in every part of its remaining range in Canada.

Part of the Fortymile caribou herd in central Yukon. (Photo: Hilary Cooke - WCS Canada Yukon)
Millions of Canadians felt the burn of just trying to breathe under smoke-filled skies this summer. Thousands had to evacuate their homes, not knowing what they might return to. These immediate impacts are even more intense for wildlife because moving to another community temporarily or staying indoors in climate-controlled conditions is simply not an option. Even our efforts to combat fire may have impacts on wildlife. For example, fire suppressants and retardants can harm wildlife and fish, especially when they enter the water. Understandably, Wildland fire management strategies aimed at protecting human life and infrastructure can also negatively impact wildlife habitat, particularly when mature conifer forests are thinned, cleared of deadwood or converted to deciduous forest through logging.

Taking action to slow the rate of climate change is vital. But we must recognize that this new fire paradigm is just one of the many climate change impacts that are here to stay. We can’t expect nature to simply cope while we try to get our climate house in order. Instead, there needs to be a shift to more proactive and holistic approaches that help sustain wildlife in the face of all the changes we have triggered – the cumulative effects of industrial development and the fallout from climate heating. A good place to start would be a strong national Biodiversity Strategy to implement the ambitious goals agreed to under the Kunming-Montreal Global Biodiversity Framework signed by Canada and more than 100 other countries in Montreal last fall.

That will require all hands on deck – governments, businesses and individuals – to start reversing humans’ destructive impact on biodiversity in the industrial age. A robust multi-pronged strategy that recognizes the links between human health, reconciliation, equity and a healthy environment will require new perspectives about what we truly value and a significant shift from the status quo. That, in turn, can set the stage for pursuing holistic approaches that include Indigenous leadership to conserve large intact natural areas and fully consider cumulative effects in all our decision-making.

Only then can we make a real difference for wildlife feeling the heat of our actions.

Climate change

Climate change

Climate change is already reshaping natural systems, changing everything from snow cover and water levels to the size and intensity of wildfires.

Yukon Climate Change

Yukon Climate Change

Why we need to plan for a changing climate and landscape

Burned and beetle-killed forests need protection too

Burned and beetle-killed forests need protection too

Insect life thrives in areas rich with dead or dying trees.
Hilary Cooke