Anatomy of a Wildfire
The current situation in southern California serves to remind us - yet again - that forest fires are as natural a part of forests as the trees themselves. In recent decades humanity has tried to overcome this vital force of nature by supressing all fires in parks, and especially those close to populated areas.
Reality is now showing us that not only can we do nothing to stop a forest fire intent on burning, but that our efforts to control nature are turning on us: we have created a situation in which a forest fire, once started, will burn all the more fiercely and relentlessly.
The summer of 2003 brought the worst forest fire ever in Canada to Kelowna, BC
"the Okanagan Mountain Park Fire became the most destructive interface wildfire in Canadian history. Before it was controlled it had razed nearly 26,000 hectares of forest and burned through the southern neighbourhoods of the City of Kelowna consuming 239 homes" (SOURCE)(note: one hectare equals approx. 40 acres) eventually incurring a cost of C$33.8 million. (SOURCE)
In the intervening years, much study and reporting has been done about the nature of wildfires; particularly regarding prevention and suppression. One frightening fact has come to light, "Ironically, however, by tampering with the natural fire cycles—and by embracing fire eradication as the overriding principle of fire management—people have set the stage for more catastrophic fires." (SOURCE) "In the boreal forest, nature's way provided a mosaic pattern of fire-ravaged stands of same-age trees, creating a natural firebreak. Interfering with nature through suppression of fire in these stands set in motion the mechanism for larger, wider-ranging and often devastating blazes."
Couple this realization with the fact that, up until very recently, silviculture practices involved planting same-age, same-species fibre. Because it's easier, and more profitable, to log similar timber in patches. There is, however, a dual unforseen hazard arising from the decades-old theory: not only does the fuel, once burning, get whipped up into an almost unstoppable frenzy (with no challenges of fire scars, old growth or decadent wood to slow it down), but the homogeneous timber becomes easy prey to insects and other parasites. As BC's current disaster with the Mountain Pine Beetle proves. "One positive effect of fire is that it regularly clears the landscape of aging trees before they become susceptible to insect infestation and disease." (SOURCE) Not to mention the underbrush, fallen trees, and other debris littering the forest floor that would normally have burned up. It is all only that much more fuel when a fire eventually does come through.
These new facts of life in the forest would be dangerous, and costly, enough. When added to the ever-encroaching home and community building into forested areas we have a particularly deadly situation. On a large scale.
Any forest fire fighter will tell you that a wildfire is a different animal than a house fire. The term 'animal' is fitting in this case, as people familiar with forest fires invariably describe them as seeming to 'have a life of their own'. In explaining the start of the current fires in southern California, experts have pointed to the Santa Anna winds. Once a forest fire reaches a certain intensity, it generates (very intense) winds of it's own. It also starts crowning (only the tops of trees burn; an extremely dangerous situation that, together with these winds, causes the fire to 'jump' considerable distances. Prevention personnel can easily get trapped in between, with no safe way out. Also, it is not uncommon for a burning crown to literally explode, sending entire branches full of fire in all directions at a high rate of speed.) (DATA) This combination of circumstances is why a few measly fire hoses are completely useless. The best that can be done is to try to prevent the fire from reaching populated areas, and to get people out as a precaution. (SOURCE; pg. 47)
Now that these facts are known, silviculture -and indeed even harvesting- practices will surely change. In order to preven at least some of these more intense fires, we need to re-plant our forests in a more natural way, rather than what is easier for human use. As for the building of homes and communities by timberlands, well . . . that unfortunately does not seem likely to stop just yet.