Size of Vancouver Island burned in 2023 Alberta wildfires: ABMI report

A Closer Look: Alberta 2023 wildfire season CTV News Edmonton's Nicole Weisberg takes A Closer Look at the 2023 wildfire season with a four-part series.

A group of researchers who studied the historic 2023 Alberta wildfires calls them “remarkable” at least in recent history.

The Alberta Biodiversity Monitoring Institute (ABMI) found 6.6 per cent of Alberta’s forest burned, disturbing as much forest as the 11 previous years combined.

“We think around 32,000 square kilometers of forest burned so that's about the size of Vancouver Island,” said Brandon Allen, who is a senior terrestrial ecologist with the ABMI.

Its count is higher than the province’s estimate of 2.2 million hectares of land burned because it includes national parks, an area outside the Forest Protection Area (FPA).

“The boreal was quite heavily hit. Places like Wood Buffalo National Park, we estimate about 20 per cent of the area was burned,” Allen told CTV News Edmonton earlier this month.

An ABMI report states nearly 750,000 hectares was scorched in Wood Buffalo National Park, an area larger than Banff National Park.

It called fires a “natural occurrence” in Alberta however it said 2023 was an “exceptional year”.

“Your upland forests, your lowland forests, your marshes, your bogs, they all seemed to be burdened relatively equal amounts. And same with how old the forests were as well,” said Allen.

“There wasn’t any sort of bias towards one habitat type being burned or another.”

Indiscriminate burning of habitat ‘not normal’ experts say

A forest fire research scientist with Natural Resources Canada said young forests are much less likely to burn than old forests.

“They just have less fuel. So less vegetation, less thick, organic soil layers that have built up over time. Less ladder fuels like shrubs and understory branches,” Ellen Whitman told CTV News Edmonton.

“The thing that we can infer from that is that there was really, really extreme weather that enabled that to happen.”

Whitman said 2023 was Alberta’s hottest and driest fire season since the 1940s.

And over the past three decades, scientists have noticed an increase in forests repeatedly burning in short intervals.

“When we burn young forests, what happens is, essentially, we're burning them before they have mature seed sources and seed availability,” Whitman said.

In severe cases, she said an impacted forest could fail to recover.

“I am much more concerned about short-interval reburns ecologically than I am about mature forest burning. It takes a long time for those mature forests to come back but they have the seeds available to do that.”

Extreme fire seasons can ‘dramatically affect forest biodiversity’: ABMI

The 2023 wildfires both increased and decreased animal habitat according to the ABMI report.

Boreal Chickadees lost just over 4 per cent of its habitat while Black-backed Woodpeckers saw a nearly 13 per cent increase.

“Species like woodpecker are going to thrive. They have all of these new nesting cavities that they can take advantage of. Some old forest birds are not going to do as well,” said Allen.

Woodland Caribou — which is considered a species at risk — lost just over 5 per cent of its habitat.

Two northern caribou ranges saw close to 13 and 14 per cent losses.

“Time will tell how these changes in the fire regime will impact caribou. But we need to make sure that we're watching and that we're ready to act quickly,” said Melanie Dickie, a senior caribou ecologist with the ABMI.

The report notes a possible greater effect on caribou is an influx of moose and deer in areas of regrowth.

“When there are more moose and deer on the landscape, there are often also more predators like wolves, which predate on caribou at unsustainable rates,” said Dickie.

She said the impact of increasingly severe fire seasons should be included in the province’s caribou protection plans.

Looking ahead

The ABMI report states the “critical question” about the 2023 wildfire season is whether it represents a rare event or something we will see more of in the future.

“If this is a one time event, this is something that these forests are adapted to. This is a very normal thing for them,” said Allen.

“If this happens every year going forward, it'll definitely impact the ecosystem more.”

Whitman said scientists have already associated warming and drying trends in Alberta to an increase in large fires and land burned.

“2023 fits with that trend and the key thing to remember is that when we have really high temperatures, the moisture holding capacity of that air is much higher,” she said.

“So even if you get more rain, hot temperatures mean that more moisture can be pulled out of your fuels so you actually need a lot of precipitation and moisture on the landscape to compensate.”