Clearcut logging greatly increases forest fire hazard

Following logging, residual slash and flammable plantations raise fire hazard for up to 30 years. Longer, more intense periods of drought and higher summer temperatures caused by climate change will exacerbate the risk.

OF ALL THE DISCOVERY ISLANDS, Quadra has recorded the most large forest fires over the past 120 years. Although the factors affecting the causes, size and frequency of forest fires applies to all of the Discovery Islands roughly equally, below we confine ourselves to describing the growing fire hazard on Quadra Island. It had fires of significant size in 1919, 1922, 1925 and 1959. All of those fires, except 1959’s, were started by humans (1959’s was ignited by lightning).

Because of the fuel conditions it creates, clearcut logging increases fire hazard, and this relationship is one of the strongest arguments for greatly reducing the scope of logging on the Discovery Islands. If clearcut logging is allowed to continue at the current rate, the risk of uncontrollable forest fire will only grow as climate change brings longer periods of drought and more extreme hot temperatures.

The most current publicly available information about the increased fire hazard created by clearcut logging on Quadra Island is contained in the 2011 Quadra Island Community Wildfire Protection Plan, written by B.A. Blackwell & Associates for the Strathcona Regional District. Unfortunately, the study used data that was already woefully out of date when the report was written and has since grown even more outdated.

A “2011” map of fire hazard based on fuel types, for example, showed the areas of highest hazard corresponded with clearcuts made in the mid 1980s and early 1990s. Since then, the prevalence of clearcuts and plantations has increased considerably and has moved southward, closer to human communities. Thus the maps used in recent discussions about fire hazard on the north end of Quadra Island were poor representations of actual hazard. The Strathcona Regional District fuel-type map doesn’t include any of the many clearcuts logged over the past 20 years in a band stretching across Quadra Island lying roughly between Maude Island in the west and Village Bay in the east.

Another part of Quadra that has been heavily logged over the past 20 years—which happens to be in the area where the 16,000-hectare 1925 forest fire started—lies south of Granite Bay and abuts the west side of Main Lake Provincial Park. The image below shows the clearcuts (in red) that have been logged in that area since 2000.

 A growing area of clearcuts and plantations south of Granite Bay has created a greater fire hazard that will persist for decades. This is the area in which Quadra’s 16,000-hectare 1925 fire began.

Provincial authorities have been largely mute on the higher fire hazard created by logging, even when it occurs close to population centres. But testimony provided to an Oregon court in 2019 revealed that clearcut logging, followed by replanting, creates fuel conditions that make fires easier to ignite and harder to control. These effects persist for decades.

The Oregon testimony arose because a land conservation organization, Oregon Wild, sued the US Bureau of Land Management (BLM) for failing to disclose the extent to which logging on public land near an Oregon community would raise forest fire hazard. The Oregon case included written testimony from a BLM fuels specialist, provided under oath, that stated that logging and plantations increase forest fire hazard. Those two fuel conditions make a fire easier to ignite and harder to control.

Logging slash left in a clearcut by Okisollo Resources on Quadra Island. The fuel left in a clearcut, even after limited slash burning, makes such areas more flammable and fires in them harder to control than fires in mature forest.

Here’s the relevant testimony by the BLM fuels specialist (we quote from the court judgment record): “The change from a ‘mature’ to an ‘early successional’ stand structural stage would change the associated stand-level hazard from low to moderate/high. The stands would go from a timber model to a slash fuel model with higher predicted flame length, fire duration, and intensity and decreased ability to control a fire, with the greatest risk of a fire start during the first 5 years following harvest. Over the next 10 to 40 years, stands would transition through stages associated with high stand-level fire hazard rating and go from a slash fuel to a brush fuel type, which are more volatile and susceptible to high fire-caused mortality rates. These potential fires would have high flame lengths, rates of spread, and intensity and would be difficult to initially attack and control. Overall fire hazard would increase for 5 to 20 years following planting, then drop from high to moderate after the next treatment.”

“Fire hazard,” as referred to in the testimony, needs an explanation. A “fire hazard rating” is an assessment of the fuel comprised of living and dead vegetation in an area—a mature forest or a clearcut or a plantation, for example. The assessment estimates the ease with which a fire can be ignited, and, once ignited, the fire’s resistance to human control. If a fire ignites in a high hazard area, or encounters such an area, it can spread more easily than in mature forest.

Fire hazard is independent of weather-related factors like moisture content, humidity, temperature or wind speed—all of which are influenced by climate change. Instead, hazard is all about fuels: the volume, type, condition, arrangement, and location that determines the degree of ease of ignition and the resistance to control. The distinction between climate effects and fuel effects is necessary to make for one important reason. Although the forests ministry can’t directly control climate change, it does have full control of how much of BC’s publicly owned forests are converted from a low fire hazard rating to a medium/high hazard rating each year. Since the early 1980s the ministry has ramped up the production of clearcuts and plantations on Quadra Island—and, as a consequence, the fire hazard.

The only way to reduce the increased fire hazard that results from clearcut logging and plantations is to reduce the rate at which clearcuts and plantations are being created.

Library of science-based documents examining the relationship between increased fire hazard and clearcut logging

Historical record of forest fires on the Discovery Islands

Record of clearcut logging on the Discovery Islands