Rekindling the flame
The images in the media this year of wild fires burning out of control in many parts of western Canada inspire fear and awe. But there is another side to the role of fire. Used with care fires can aid and are necessary in maintaining certain ecosystems. Last autumn I was fortunate enough to participate in the prescribed burns taking place at the Cowichan Garry Oak Preserve by Somenos Marsh on the outskirts of Duncan.
Fire frequency plays a big role in fire intensity. The longer fire is absent from a landscape the greater the amount of accumulated biomass (fuel) as well as “ladder fuels” (the limbs which help get the fire into the crowns of trees). If fire is excluded from the landscape for a long time the chances of catastrophic fires such as the ones we are seeing on the news are greater.
The fires I witnessed last year were of the low intensity variety. The purpose was to affect the structure and composition of the Garry Oak meadows. The burning reduces in-growth and crowding of trees, rejuvinates shrubs and helps control invasive species if the area is rich in native plant seeds – if it isn’t the result may be an opportunity for invasive species to access open ground. The new growth – whether grass or shrubs has greater palpability for herbivores.
Traditionally First Nation’s fire practices were complex and varied, but in our area they used fires to influence the structure and composition of the landscape, for wildlife management as well as for maintaining food plants. Most of the focus of western science and anthropology in our area has been focused on the First Nations maintenance of deep soil Garry oak meadows. They are the habitat of the Camas plant, the bulbs of which were an important carbohydrate-rich food, valued for local consumption as well as a valuable trade product.
The occasional burning of berry patches reduced the encroachment and shade competition from trees, as well as pruned the plants by burning off the tops but leaving the roots intact. The phosphorus that was released also had a fertilizing affect.
First Nations also employed fire along travel routes both as a way to maintain the corridors as well as to create and maintain the food plants associated with fire.
Every few years when catastrophic fires or fires close to human habitation occur, there is generally some recognition by planners and land managers of the role of prescribed fire in reducing risk to lives and infrastructure. However, landscape fires are generally not a part of our current culture and with our history of fire suppression, introducing fire to the land must be done with extreme care. There are good examples in BC and beyond of prescribed fires – particularly in large wilderness parks, but also places such as High Park in Toronto where prescribed fires are a standard and frequent management tool. The example of the Cowichan Garry Oak Preserve fires last year illustrates how it could be employed in our local context as well as in a near urban setting in a way which benefits the landscape as well as reduces fire risk for surrounding properties.
Click here for videos: Prescribed fires in a Garry Oak meadow – Irv Bannerman – site manager at the Cowichan Garry Oak Preserve
Jay Rastogi is a naturalist and educator in Yellow Point. You can reach him at ecoforestry [at] gmail [dot] com