6

In September of 2017, for nearly two weeks, the Kenow Wildfire raged through a swath of Canada. Its largest impact was on the Waterton Lakes National Park in Alberta. More than 38,000 hectares, (94,000 acres), of land, including 70% of the forested area in the Park, were completely destroyed by what was called "extreme fire behavior." According to CBC News, the full total, including the park and its surrounding regions in British Columbia, was approximately 42,000 hectares, (103,784 acres).

We have a few questions about the Kenow Wildfire here on the site. This one was seeking information as to how many animals had been found deceased in the area of the fire.

There was a comment under that question which mentioned eventual benefits to animals after this type of fire.

I just finished reading on the Parks Canada website that the animals that return to the park after a fire really benefit from the blaze. It's almost like a reset button. The long term effects of forest fires are really healthy for both the plant and wildlife. – ShemSeger Sep 30, 17 at 5:21

That comment made me curious about a few things.

  • Are there studies and other sources which corroborate what the Parks Canada website said?
  • If so, where are some and what types of things do they say?
  • What is meant by "really benefit from the blaze?"
  • What has to happen for such a severely damaged area to be considered "reset?"
  • What constitutes enough "long term effects" to make it "really healthy for both the plant and wildlife?"
  • Obviously, every forest fire is different, but if there really is a benefit to the returning animals, is there an approximate time when this area will be recovered enough to provide this benefit?
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According to United States Forest Service, fire has a number of benefits for the wildlife including more nutrients in the ground, more open spaces, there are some plants that need fire to spread and it helps control invasive species.

Fire offers many benefits to wildlife and plant species. First and foremost, a fire is a natural process, unlike mowing or logging. Fire returns nutrients to the soil quickly, versus the years it takes for grass clippings, dead leaves, and logs to decompose and provide nutrients. In fact, it's not uncommon to see new growth within a few days of a fire!

Fire also opens up dense areas and helps maintain meadow habitats. Several animal species use these open areas for food and shelter. Birds such as bobolinks and eastern meadowlarks require open grasslands for feeding and resting. Mammals such as moose, deer, and rabbits rely on the new growth produced after a fire for food.

Fire also benefits several plant species such as the endangered sandplain gerardia and wood lily, both which need fire to reproduce and grow. The endangered Delmarva fox squirrel and red-cockaded woodpecker rely on fire to maintain their pine forest habitats.

Fire also helps control non-native invasive plant species. Non-native invasive plants are plants that have been introduced from another part of the world, and have "taken over" their new habitat. No matter where you live, chances are there is some type of invasive plant in your neighborhood. Here in the Northeast, common invasive plants include purple loosestrife, Japanese knotweed, common reed (aka Phragmites), and honeysuckle. Controlled burning can remove these invasive species from a particular area, allowing space for native plants to grow.

Source

There was also a more in depth study also done by the Forest Service which tracked the benefits to animals in areas that had been touched by fires. Whether or not fire increased or decreased the number of animals depended on the species of animal.

Deer and Elk

Deer summer-fall use (annuity value 1. 9) declined the first year after fire, but then increased to levels approaching 2.5 times the control through the rest of the 20-year evaluation period (fig. 3). Deer winterspring use also declined immediately following fire, returned to the control level for a few years, and then increased to levels exceeding 10 times that of the control.

..

For both trap periods, deer mice increased the first year after fire, then declined to the level of the control at 7 years. After 7 years, there was another increase to 2.5 times the control level in the summer, and 6 times the control level in the spring. Annuities were 1.8 and 3.3 for summer and spring, respectively

...

Total bird numbers (annuity value 0.71) increased the first year after fire, then decreased to below the prefire level for the remainder of the evaluation period

Source

I found another study which went through and listed the benefits for each species and it looks like some species benefit and others do not, depending on the species and type of fire.

Pedersen et al. (2003) modelled effects of fire and concluded that small fires may benefit sage-grouse, but large fires (>10% of the spring-use area) occurring at high frequencies (17 years between fires) could result in their extirpation.

...

Fire is important to pronghorn because it creates the desired density of grasses and forbs and improves quality of forbs for foraging (Yoakum 2004). Fire can also maintain shrub cover at desirable densities and heights for pronghorn

...

At the species level, however, western bluebirds benefitted from severe- and moderate-fire, whitebreasted and pygmy nuthatches benefitted by moderate-fire, but mountain chickadees were negatively affected by any fire.

Source

As you wanted to know what the timelines were, I would suggest the charts starting on page 5 of this study.

If you are looking for more information, I would suggest these resources,

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