Parks

Ecological fire

On an unseasonably warm April afternoon, I rode my bike to meet my fellow colleagues standing in a semi-circle on the precipice of Toronto’s High Park parking lot and edge of the park’s black oak savannah. A group of roughly one hundred, comprised of Indigenous leaders, community members, parks staff, and forestry professionals were gathered to participate in the opening proceedings of the High Park prescribed burn, or Biinaakzigewok Anishnaabeg, which, according to Toronto’s City website, translates to “a responsibility for a cleansing burn by all Native Peoples” in the Anishanaabemowin language. Although the City of Toronto has been conducting burns in High Park on a semi-annual basis since 2011, this was the first burn that included an Indigenous ceremony highlighting the cultural significance of fire in Indigenous culture and its historical use for land management and protection.

The prescribed burn at High Park in Toronto gets underway. IMAGE/ Sarah MacLean

The use of fire as an ecological management technique has been widely understood and employed by Indigenous peoples across North America for millenia. In Ontario, several landscape types and specific plant species have evolved and adapted overtime to periodic wildfires, either by natural occurrence or with the help of human intervention: open grass meadow ecosystems like the tall grass prairie and black oak savannah, once commonly found in southern Ontario, and the iconic jack pine barrens of northern Ontario. Likewise, the boreal forests, covering much of Ontario and Canada depend on fire for management of their ecological health and structure. Periodic fire in these landscapes control the growth of invasive plants, recycle nutrients, and create habitat diversity. 

In the wake of recent devastating wildfires across Ontario, and much of north America, the idea of fire as an agent of ecological regeneration and protection may seem counterintuitive. However, it is in fact the colonial legacy of fire suppression in combination with warming temperatures which has contributed to the ripe conditions for these large-scale fires. Learning from Indigenous teachings of using fire to cleanse the forest of highly flammable debris and make way for new growth is a key strategy in defending and adapting to our current climate crisis. 

Observers of the annual High Park burn. IMAGE/ Sarah MacLean

High Park’s landscape is home to notable fire-dependent species the black oak (Quercus velutina) of the black oak savannah, an ecosystem once common across North America, now greatly reduced (less than 0.5 per cent of its original area remains), as its open understorey was seen as prime farmland to early European settlers and hundreds of years of subsequent fire suppression has reduced its expansion. It is estimated that the portion of black oak savannah preserved in High Park is 4,000 years old and has been recognized as an important relic of Indigenous land stewardship.

The High Park burn continues. IMAGE/ Sarah MacLean

Other tree species found throughout Ontario like the jack pine (Pinus banksiana) and black spruce (Picea mariana) also benefit from ecological fire. Their tightly sealed serotinous cones rely on intense heat to release seeds and initiate new growth. The young seedlings propagate in open areas freshly created by fire, ensuring the continuation of the species. Similarly, early successional deciduous tree species like aspen and birch take advantage of the newly cleared areas and sunlight. The process of clearing the land is reciprocal by nature—allowing for new habitat and the rapid sequestration of carbon from the atmosphere. Broad-leaved trees like aspen and birch are also more naturally resistant to wildfires, as they contain more water than conifers and provide more shade to keep the forest floor moist. A cluster of broadleaf trees create natural fire breaks during the summer when their leaves are out.

The burn included a gathering and ceremony with Indigenous leaders. IMAGE/ Sarah MacLean

Native grasses and wildflowers that thrive in full sun are also naturally key components to the post-fire landscape and provide much needed habitat to many animals, including birds and pollinators. Species like little bluestem (Schizachyrium scoparium), big bluestem (Andropogon gerardii), and Indian grass (Sorghastrum nutans) are native Ontario grasses commonly found in the black oak savannah. 

The annual prescribed burn helps regulate High Park and keeps the habitat healthy. IMAGE/ Sarah MacLean

Other favourite native savannah wildflowers include butterfly milkweed (Asclepias tuberose), cup plant (Silphium perfoliatum), cylindrical blazing star (Liatris cylindrical), and finally the wild lupine (Lupinis perennis). A surprisingly helpful species in the post-fire landscape, wild lupine, like other members of the tuberous legume family, are nitrogen fixers. They are often one of the first species to propagate disturbed landscapes, helping to expedite soil regeneration. Finally, wild lupine is the sole larvae food source for the now endangered Karner blue butterfly, last seen in Ontario in 1993.

Other early propagator understorey shade-loving woodland plants like ferns, mosses, bunchberry (Cornus canadenis), as well as sun-loving blueberries (Vaccinium varietals), are fire-adapted species that can survive most moderate forest fires thanks to their deep rhizome layer. The influx of nutrients following the fire creates rich soil to nurture new spouts.

The annual prescribed burn helps regulate High Park and keeps the habitat healthy. IMAGE/ Sarah MacLean

Fire is becoming a common elemental force on our landscape again, and so it is imperative we better understand the ecological and cultural importance it carries. Ecological fire, through controlled burns, is a vital tool in the conservation and management of Ontario’s diverse landscapes. Collaboration between fire managers, Indigenous communities, and stakeholders is crucial through this process. By embracing this powerful practice, we can help to foster resilient ecosystems, support wildlife, and protect unique natural treasures that define Ontario’s landscape in the face of a changing climate.

For more about the High Park prescribed burn, check out highparknature.org. And for more about Indigenous fire stewardship, check out Blazing the Trail: Celebrating Indigenous Fire Stewardship in Canada, by Amy Cardinal Christianson.

Text/ Sarah Maclean, OALA (inactive), is a landscape designer based in Toronto.

The annual prescribed burn helps regulate High Park and keeps the habitat healthy. IMAGE/ Sarah MacLean