By Paul Homewood
Last year’s wildfires in Canada were inevitably blamed on climate change. But forestry experts have known for years that it was just the sort of conflagration that was waiting to happen , thanks to decades of fire suppression:
Alberta’s aging forest puts our communities at ever greater risk of wildfires, said the Alberta government’s expert committee on containing wildfires.
In 1971, more than half of Alberta’s boreal forest was deemed to be young, with about a third immature, five per cent mature and a small portion deemed “overmature”.
By 2011, that had changed to less than 10 per cent young, about a quarter immature, more than 40 per cent mature, and more than 20 per cent overmature.
“Before major wildfire suppression programs, boreal forests historically burned on an average cycle ranging from 50 to 200 years as a result of lightning and human-caused wildfires,” the panel found in a report released in 2012.
“Wildfire suppression has significantly reduced the area burned in Alberta’s boreal forest. However, due to reduced wildfire activity, forests of Alberta are aging, which ultimately changes ecosystems and is beginning to increase the risk of large and potentially costly catastrophic wildfires.”
The panel’s report came in response to Alberta’s unprecedented May 2011 fire season, which culminated in the deadly and costly Slave Lake fire that killed one helicopter pilot and took out 510 homes and buildings costing $700 million. The Alberta government’s Sustainable Resource Development department set up a panel to figure out how to deal with this kind of threat.
The panel reported that Alberta can expect more such dire situations due to humans living closer to the forest, and the aging of the Alberta forest.
“More Albertans are choosing to live, work, and play throughout the forested regions of the province, with investment and activity in Alberta’s wildlands accelerating. As a result, the risk of wildfires, and the threat they pose to lives, homes, communities, and industry is increasing.”
In May 2011, the committee reported that “189 human-caused wildfires ignited across the province and threatened over 23 communities/locations (e.g., camps, worksites, parks, wildfire lookouts). Strong, sustained winds from the southeast created wildfire suppression challenges.”
The number of human-caused fires has been rising rapidly, from slightly more than 200 per year in 1993 to more than 1,100 a year by 2011. After human activity, lightning is the next biggest cause of wildfires, responsible for 40 per cent of them.
Before the Slave Lake fire, there had been few major wildfires in Alberta that took out homes.
“The last wildfire causing widespread damage to a community was in 1919 when the Town of Lac La Biche was destroyed, and 14 people lost their lives. Since 1919, and prior to the 2011 wildfires in the Slave Lake area, the most significant losses were experienced in 2001 when a wildfire destroyed 10 homes in the hamlet of Chisholm.”
But wildfires were to be expected.
“Wildfire is a natural part of the life cycle of the boreal forest; many of the vegetation species, including trees, are well adapted to large, intense wildfires. These boreal wildfires typically burn as ‘crown fires,’ and are responsible for most of the area burned in the boreal forests of North America, Europe and Asia. Intense wildfires consume forest canopy and can spread from treetop to treetop, releasing huge quantities of sparks, smoke and other gases.”
The Government of Canada’s environmental website explains how fires are an essential part of forest evolution:
Alberta’s population has increased fivefold since 1951.
The fact that so many people now live among these forests makes one wonder how this balance of human and ecological objectives can ever work.
via NOT A LOT OF PEOPLE KNOW THAT
March 29, 2024 at 04:06PM
Iowa Climate Science Education 