The summer of 2014 has seen its fair share of wildfires in the Okanagan. Fires broke out on Mount Boucherie and in Smith Creek in West Kelowna, forcing hundreds to evacuate their homes.
Over the past decade or so, a series of major wildfires, including the Okanagan Mountain Park fire, Rose Valley fire, Trepanier fire and the Glenrosa fire, have resulted in thousands of hectares of dead trees across the landscape. In some cases, these burned areas have been salvaged – the dead trees removed and disposed of through lumber milling or chipping.
In many cases, especially those involving private land or non-commercial Crown land, these burned areas have not been treated – and have simply been left as is with thousands of dead trees slowly rotting and falling apart. These dead trees, once they’ve fallen to the forest floor, constitute a significant fire hazard – one that in some ways is greater than the hazard that existed before they were killed.
There is a belief among some that wildfire, like lightning, never strikes twice in the same place (the people of West Kelowna especially should be questioning this parable), and that because there was a recent fire in a certain location, the site will not burn again for quite some time. This idea has lead to a false sense of complacency when it comes to reducing hazards.
The most hazardous fires are ones that spread quickly, throw out thousands of embers over long distances and release high levels of energy – energy that is most easily visualized in the towering flames of crown fires.
Developing a mental picture of a forest in the Okanagan that provides the fuel necessary for this type of fire is easy, it contains lots of tall, thick grass and shrubs, and lots of large logs and limbs mounded on the forest floor. There may be some green trees or possibly some young trees, but not a dense forest.
This actually describes the typical situation found on sites that have been burned in a wildfire and not cleaned up afterward. The tall grass cures quickly in the early summer and provides just the kind of fuel for fast-moving and very dangerous fires (the majority of wildland firefighter fatalities are on fires with tall grass).
The lack of a dense forest means the grass receives lots of direct sunlight and low humidity – both of which help it cure quickly. Low forest density also means the wind speed at the level of the grass is unobstructed and moves rapidly.
The large volume of dead wood from the previous forest, once ignited, releases massive amounts of energy. This energy release is capable of propelling thousands of embers out ahead of the fire and onto receptive fuel.
It’s a lot to ask of our municipal fire departments to tackle wildfires in these types of situations: tall, fast-moving flames with hundreds of spot fires from embers and very poor visibility. Yet, by not treating post-wildfire fuels, that is exactly what we are asking them to do.
Provincial and local governments must find a way to incentivize the treatment of these sites, and whatever program they develop must be
applicable to private land as well as municipal land (to recover treatment costs for private land a charge could be levied against the value of the property – this would also apply as a further
incentive to landowners to be proactive in
It will not be cheap. Many of these sites contained little recoverable value before they were burned and whatever value was there has certainly been diminished by the fire. However, as costly as it might seem, it pales in comparison to the potential cost to society if these sites are not managed properly and the hazard removed.
Robert W. Gray is a fire ecologist working throughout B.C. and internationally on fire science research, management and policy.