Page 1 of 1

Wildfire control in the American Southwest

Posted: Sat Jul 06, 2013 9:35 pm
by Rand
This article is probably old hat to a lot of you around here, but thought it was a nice overview of the challenges presented by decades of wildfire suppression in the American Southwest. Might be a good reference when talking to non-tree people about the issues.
Fire is, of course, vital to just about every Western ecosystem. And historically it has come in many shapes and sizes, leaving behind mosaics of green and black. Some areas remain untouched, while in others, the flames keep low to the ground, burning lightly. Elsewhere, the fire may storm through the crowns of the trees, killing many of them. Certain types of forest, like spruce-fir and mixed conifer, naturally burn in such stand-replacing fires, while drier, lower-elevation forests, like the ponderosa that covers much of the Southwest, are adapted to frequent light or moderate fires.

But as any fire ecologist will tell you, the amount and type of fuels, and the conditions that influence fire size, have changed drastically over the past century. Logging removed large trees and left flammable thickets; livestock grazing reduced the grasses that once regularly carried fires, thinning new trees and undergrowth. Meanwhile, land managers snuffed out every wildfire they could. Add climate change, which is making most of the West hotter and drier, and epidemics of tree-killing pine beetles, and conditions are prime for large, severe wildfires. ... -wildfires

Re: Wildfire control in the American Southwest

Posted: Mon Jul 08, 2013 1:19 am
by Don
Good point.
One point they missed was how the American Southwest experiences a weather feature regionally called the Monsoon. Around late June sometimes, more likely in July, and inevitably by August, the humidity picks up in the afternoon, from weather emanating from the SE, and results much of the time with lightning and thunder storms, sometimes with rain, sometimes without. Huge stacking cumulus clouds build up, and all firefighters eyes are peeled. And the public as well, as the lightning and thunder is quite an experience. This pattern has been long a feature of the Southwest and the frequency of lightning downstrikes is exceeded only by a few locations, and not by much. For much of the ponderosa pine forest here (largest in the world), such a frequency leads to many small fires. This for many centuries kept wildfire burn intensity low and prevented large catastrophic wildfires.
The monsoon season has changed significantly.
The USFS practice of putting out every wildfire from 1920's to 1990's left the region with abundant regeneration, freed of the once frequent ground fires. Much of the Southwest is now trying to return to previous more natural fire regimes. Forests around Flagstaff AZ have a bit of a head start, and much research to help pave the way.
Hopefully sequestered funds and a stumbling economy will soon resolve. Lest we burn. The Yarnell Fire that recently took nineteen lives of the Granite Station hotshot crew is an unfortunate example...