http://youtu.be/mlrqpqEIuPg
Firefighters say they’ve never seen fires burn the way they did in 2013.
That sentiment has been heard before. In 1988, 2000 and 2007, fires grew in size and ferocity across the American West, exceeding the experience and knowledge of firefighters and scientists alike.
This year, fire returned to places that had burned before: Colorado Springs, Pine, Ketchum, Yellowstone and Yosemite. The fires of 2013 burned through many of our previous ideas about how we can live with fire.
What’s different this time? Science is connecting hotter, bigger fires and a longer, more intense fire season with changes in the climate.
–Long before fire season, the mountains are undergoing change. Winters are warmer, meaning smaller snowpacks that melt sooner. That means runoff ends earlier and the forests dry out earlier; fire season starts earlier and lasts longer. When summer arrives, hotter, drier Julys get fires started earlier and bigger. In August and September, low humidity, wind and other unstable atmospheric conditions create erratic burning that overwhelms the best prevention and firefighting tactics.
–During fire season, fire bosses are changing tactics. They might pull their crews out of the way of extreme fires and evacuate communities more promptly. The bosses work to “herd” fires into previously burned areas, making them easier and cheaper to fight. Communities can clear brush and other fuels away from homes, providing firefighters with “defensible space.” But those measures have to be regularly renewed. In some rural residential areas, topography and fuel still make them nearly indefensible, as the Fall Creek area west of Pine found this summer. And once homes in the “urban interface” do start burning, wildland firefighters have to adopt urban tactics.
–After the fires, forests face tougher conditions in which to recover. Fires in parts of the Northern Rockies now burn so frequently or so hot that the trees don’t get a chance to grow big enough to produce seeds for the next generation. Even in forests with enough trees, hotter, drier conditions cause fewer seeds to germinate and more seedlings to die.Some won’t be forests again: Sun-baked south slopes are turning from forests to brush, as can be seen near the Lowman-area fires of 1989. Over time, more low-elevation forests could return to brush and grasslands. Low-elevation species such as ponderosa pines will move higher and farther north to cooler, moister conditions; high-elevation species such as Douglas firs will recede as fire frequency increases.
The bottom line: Nature is adapting to changing conditions. The fires of 2013 taught us that humans have to adapt to new realities about fires and forests, too. Our practices and our developments were designed for conditions that no longer exist.
