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Prescribed burns renew forests naturally
By Randy Shore
Preserving and encouraging biodiversity is embedded in the ancient practice of “cultural burning,” according to a B.C. post-doctoral researcher. Dr. Kira Hoffman estimates that 85% of the Earth’s biodiversity is being stewarded on vast, mainly undeveloped lands managed by Indigenous people, who comprise just five per cent of the world’s population.
Studies cited by Hoffman found that after Indigenous-controlled fire regimes, known as cultural burns, were displaced by colonization, high-intensity fires had occurred, and biodiversity was diminished. Supporting Indigenous-led cultural burning and prescribed burns of forest and grassland ecosystems is intended to protect human settlements from wildfires, improve ecosystems and encourage biodiversity, she explains in the study, Conservation of Earth’s Biodiversity is Embedded in Indigenous Fire Stewardship published in the journal Biological Sciences.
The Western practice of fire suppression has “altered fire activity and is threatening biodiversity at a global scale,” the study notes. “Fortunately, the revitalization of Indigenous fire stewardship is demonstrating the value of routinely applying controlled fire to adapt to changing environments while promoting desired landscapes, habitats, and species and supporting subsistence practices and livelihoods.”
In short, evidence is mounting that controlled burns reduce the intensity of wildfires and benefit species at every level of the landscape.
“For example, in northwestern B.C., cultural burning in the sub-boreal forest happens in the spring and the fall, often while there’s still snow on the ground,” said Hoffman in an interview for the University of B.C. “These low-severity fires are used to clear dead and dry fuels and promote the growth of new plants, which supply fodder for wildlife.”
“Fires also replenish nutrients to the soil and are important in flood mitigation. When used at the correct time in the spring, you can get a lot of new growth, which absorbs excess water from the ground, thus decreasing the risk of flood in many communities.”
Researchers reviewed 53 studies conducted across the globe from 1900 to the present day and found that about 80% of them reported positive effects of fire on biodiversity, from microbes to mushrooms, large mammals and reptiles, along with trees, shrubs, and grasses.
“Enhancing global biodiversity is possible through valuing and supporting Indigenous-led approaches to fire stewardship and ecosystem management,” she said. “Cultural burning, in particular, can help protect ecosystems and human communities from increasingly destructive wildfires, while reviving important community-based practices.”
The B.C. Wildlife Federation has partnered with several First Nations and conservation organizations to expedite controlled burns in British Columbia’s backcountry.
Last spring, the BC Wildfire Service led controlled burns near Riske Creek and Tl’esqox First Nation. The burn covered about 33 hectares near Cotton Ranch, 30 kilometres southwest of Williams Lake.
Another 10-hectare burn was undertaken in October near Doc English bluff east of Riske Creek to restore grasslands and improve forage. A 27-hectare burn northwest of Batnuni Lake was undertaken to restore native grassland ecosystems by reducing encroachment by aspen trees.
Grasslands in the Cariboo-Chilcotin were historically renewed through low-intensity fires, which prevent tree encroachment, rejuvenate the understory, and maintain open grasslands and mature forests.
Open grasslands and shrub-steppe habitats along the Peace River are being lost to natural succession and industrial development, resulting in the loss of important breeding habitat for sharp-tailed grouse. Prescribed burning and other restoration techniques will also begin to restore native grassland and shrub-steppe ecosystems to benefit grouse and improve winter range for elk, mule deer, and moose.
In the second year of the program, approximately 130 hectares of grouse breeding habitat will be restored by removing tree cover and reducing dense shrubs. Success of restoration efforts will be measured through pre- and post-treatment population surveys and vegetation assessments.
The BCWF and its First Nations partners are pursuing three prescribed burns in 2023 covering more than 1,500 hectares in B.C.’s dry Interior to reduce wildlife risks and enhance habitat for bighorn sheep and mule deer.
e-KNOW file photo
Randy Shore is a Communications Specialist at the B.C. Wildlife Federation.
