A Growing Threat to British Columbia's Environment?
WILDFIRES
What are Wildfires?
A wildfire, wildland fire, forest fire, or bush fire refers to an unplanned fire in wilderness vegetation or bush, including grass fires, forest fires, and scrub fires. It is a self-sustaining, rapid, high-temperature biochemical oxidation reaction that releases heat, light, and other products. For a wildfire to occur, the essential components of heat, oxygen, and fuel need to be present. Typically, a wildfire reaches temperatures of 200-1000°C on forest floor.
Temperature increase over the next century will likely only have a trivial impact on wildfires and wildfire behaviour. Fire intensity is far more significantly affected by fuel quantity, fuel dryness, and wind strength. Changes in rain frequency and intensity, on the other hand, will impact the drying of fuels, as well as the availability of fuel. Climate change will thus impact wildfires.
(Underwood & Held 2012, Keller & DeVecchio 2019)
British Columbia
British Columbia is the westernmost province of Canada, bordering on the Pacific Ocean. The region is dominated by mountain ranges, namely the Coast Mountains, the Cassiar Mountains, and the Columbia Mountains. Due to the diversity of the landscape and mountain ranges, the climate varies depending on the region, from mild, rainy oceanic climates with 3,000 mm of precipitation a year in the south, to semi-arid interior valleys with less than 300 mm of precipitation a year. Most of the population is concentrated on the Pacific Coast, notably in the area of Vancouver.
Why is it important to talk about Wildfires in British Columbia?
On the one hand, wildfires are a natural process, on the other hand they can be caused by humans. No matter the origin, a wildfire can have considerable impacts on the environment, some positive, some negative.
Should a wildfire break out close to human infrastructure, or spread towards it, said infrastructure is in danger, costing Canada hundreds of millions of dollars each year. Human lives might also be at risk.
The Canadian wildfire season 2023 was one of the most devastating wildfire seasons in recorded history. Over 18 million hectares of forest burned down, an area more than twice the size of Austria. And we don't know how climate change will impact wildfires in the upcoming years and decades.
Learn more about Wildfires in British Columbia
Thank You
for your interest in the topic of wildfires.
What are the Impacts of Wildfires?
Effects on the geologic environment
Extremely hot fires can leave a hydrophobic layer behind in the soil. This layer increases the surface runoff and thus the erosion because the burned surface now lacks vegetation to anchor the loose soil above the hydrophobic layer. Soil erosion and landslides are a common occurence following wildfires. A hydrophobic layer can also increase the risk of floods. On the other hand, carbon accumulates on the surface during a fire, increasing the nutrient content of the soil.
Effects on the atmospheric environment
In the short-term, large wildfires create their own clouds and release smoke, soot, and invisible gases that contribute to air pollution, potentially even thousands of kilometres downwind. Wildfires can also contribute to the formation of smog, possibly leading to the development of harmful ground-level ozone.
Effects on the biological environment
Some plants are more susceptible to fire than others, and even if a plant does not die in a wildfire, a fire can make it vulnerable to later destruction by disease or drought. On the other hand, some plants need wildfires for the continuation of their species, e.g. seeds remain dormant in the soil until opened by the heat from a fire.
Animals are mostly able to escape or hide from the danger posed by a fire, but changes in vegetation and vegetation cover after a fire can have an impact on habitats. Fish and other aquatic species may suffer from increased sedimentation, and water temperatures might increase.
Regarding humans, a wildfire and the increased erosive potential after might affect the water quality of streams and lakes. Smoke and haze can harm human health, e.g. eye, respiratory, and skin problems might be caused. And, of course, infrastructure can be damaged.
(Keller & DeVecchio 2019)
