Canada –Logging sites present burn hazards; effects of ‘wholesale removal’ of forests’ carbon capital doesn’t mimic fire: experts
Logging B.C.’s beetle-killed pine forests can, in theory, reduce the risk of a wildfire.
But when fire ecologist Bob Gray visits a logging site, he can see just the opposite: a heightened fire risk because of so much uneconomic wood left on the ground.
“There’s more of a mess afterwards,” he said. “If we’re just going to highgrade and take the best logs, that’s not good. We’re exacerbating the problem. Some sites you’re walking four feet off the ground on logs.”
Salvage logging has been held up by government and industry, in part, as a way to control the threat of forest fires posed by the beetle-killed pine trees.
But Gray says industry cannot log all the pine forests before they collapse – making it important to take a more strategic approach to salvage logging. He urges forest managers to target areas where fire tends to travel – based on wind and topography – thereby creating fire breaks while ensuring protection of important wildlife habitat, power lines and communities.
“If we’re going to salvage, we need to do it where it’s going to give us the biggest bang for the buck,” he said.
The relative fire risk posed by dead pine is driven largely by the vagaries of weather, especially temperature, humidity, winds, and the length of time between rainfall.
The underlying soils can also play a part. Because dead pines no longer draw up water like live trees, that can make for wetter conditions on the forest floor and a reduced chance of fire ignition.
The risk of fire can also be lessened by other healthy species such as fir and spruce mixed with the dead pine. A 2004 report by Marvin Eng – then a provincial landscape ecologist with the forests ministry – noted that “conducting salvage operations based on the premise of reducing fire risk is not recommended” and that “salvage logging can impair ecosystem recovery.”
Today, as manager of special investigations for the Forest Practices Board, Eng states that the log-to-reduce-fires argument remains inconclusive based on the latest science.
“To wholesale cut down all the trees in Prince George timber supply area, you just cannot connect those dots.”
And while industry argues logging alters the landscape much as a forest fire would, others reject that idea.
“It does not mimic fire,” asserted Art Fredeen, acting chair of the ecosystem science and management program at the University of Northern B.C. in Prince George.
“It is a wholesale removal of the carbon capital of the forest. Fire doesn’t take everything.”
Gray confirmed that “in the majority of cases” logging does not mimic the effects of wildfire. He noted that the effects of a wildfire are wide-ranging: frequent “low-severity” fires tend to leave larger trees standing, but burn up woody debris on the forest floor; less-frequent “high-severity” fires kill most, if not all, trees.
“After a high-severity fire the trees all remain on the site to provide nutrients, wildlife habitat, seed, etc. for the next forest. Clearcut silviculture systems remove the majority of trees, and, in some cases, the disturbance is occurring much more frequently than wildfire ever did historically.”
Training in fire ecology at the University of Montana, Gray laments the lack of such programs in Canada.
The study of fire is being downgraded in the curriculum of forestry schools, even as climate change is expected to lengthen the fire season by latitude and elevation, he said.
“Unfortunately, there has not been a lot of empirical science” on the specific fire risks posed by the pine beetle attack, he added.
“Here we’ve got the largest [beetle] epidemic in North American history, if not world history, and the implications are huge as far as fuel and forest dynamics and there’s been almost zero research …”
Asked what studies the province has funded on dead pine and fire risk, the Ministry of Forests, Lands and Natural Resource Operations said in a statement it conducted two experimental burns in 2006 at Carrott Lake, about 75 kilometres southwest of Vanderhoof.
Those studies occurred when the trees had recently died and the red needles were still on the limbs.
In 2012, the province will revisit the site to test how fire behaves in stands where the needles have dropped, with varying amounts of wood as deadfall.
The ministry said it is also analyzing the state of knowledge about the rate of spread under different fire and weather conditions, with the results to be published in a peer-reviewed journal in 2012.
Phil Burton, manager of northern projects for the Canadian Forest Service, said fire is thought to react differently as the pine dies, loses its needles, and eventually falls over, but research is ongoing.
“A lot of these are anecdotal observations,” he cautioned.