Thursday, May 7, 2009

Man and Fire

last week, a small, once-controlled brush fire outside of Santa Barbara exploded into a house-eating inferno, fueled by 100 degree temperatures and the Shakin Shakin Shakes, those Santa Ana winds. As of today, it is 80 percent contained, although additional winds are probable.

California is blessed with many natural wonders, and cursed, as well. We have mountains so full of snow that they were named it - Sierra Nevada. We have a two-river Delta (one of only a handful) that supplies 20 million people with drinking water. We have a gigantic coastline, huge, rugged, highly variable terrain, and our state claims multiple climates with dozens of microclimates. In the Summer, we are a desert, and in the winter, we are often inundated with deluges. But, we have changed our natural wonders to a great extent, and in these changes comes an increase in variation and intensity. The Sierra Nevada may one day be renamed the Sierra Seca. That river system's wildlife is quickly crashing, and the wonderfully varied and beautiful terrain can't seem to keep folks from wanting to build on it, to better enjoy its beauty, yes, but with the result that we find ourselves living by the whims of fickle Mother Nature.

We have also changed much of the flora of our beautiful state, and the effects of this paradigm-shift are felt most directly in the new nature of our wildfires.

Prior to Europeans, California's flora and fauna developed with a particular relationship to fire and each other. Most of our herbivores were browsers, pushed by a considerably large number of large predators, primarily wolves and very large brown bears, but also mountain lions, bobcats and the like. Our primary flora, therefore, were wildflowers and slow-growing bunch grasses. The animals seeded large areas of land, and many plants only seeded once every few years. Fires regimes, caused by lightning and people, usually burned with a low intensity, because the slow-growing bunch grasses kept green all year, and protected their roots with tight "bunches" of grass blades. Forests of huge oaks, pines, and redwoods required these fires, as their seeds needed heat to open, and their seedlings needed light and nutrients.

This habitat regime changed dramatically with the arrival of Europeans. We brought livestock that ate entire plants, and we kept them protected and in the same places for longer periods of time. We also fed them grass seed from our native lands, grasses which had developed a relationship with very different animals. The new grasses, which grow, seed, and die within a few months, quickly replaced the slower-developing native habitat, which wasn't used to being eaten completely down to the roots. Within a short period of time, much of California changed completely, giving our state its golden hue during the Summer, and bringing on a dramatic shift in the nature of fire.

The new grasses and weeds die quickly, creating fuel from the tip right down into the soil. Fires set in this fuel often burn far hotter, burn soil habitat and seeds, and leave a scorched waste. They also burn into the upper canopies of the trees, killing many adult trees that had survived the previous fire patterns for hundreds of years. This is why we instituted a fire-suppression program over 150 years ago, and in so doing we allowed the buildup of deadwood, leaves, and other combustible materials. Consider this in light of projected hotter and drier weather patterns, and we have a serious problem.

Now that many more of us are living close to these wild and altered landscapes, it is imperative that we do something to both improve habitat and fire. Right now, many are under the impression that a completely barren "defensible space" as far as you can make it is the best thing to do. But, wildland firefighters know that the best thing we can do is to eliminate the non-native grasses and forest duff that fuel these monsters, and build houses that don't catch fire so easily. No amount of defensible space could have saved most of the homes in Santa Barbara, because 40 mile-an-hour winds will carry sparks well past any clearings, and even over large freeways and the like. However, if those sparks land on green plants or metal roofs, and the fires from which they came were burning low and through the underbrush instead of licking hundreds of feet into the air, we would all be much safer.

The answers are easy, but expensive. They also have the great upside of improving ecological habitat as well as human safety. The alternative, however, is a complex series of ever-more-useless attempts to postpone the inevitable, also expensive, while encouraging further ecological degradation. Which way shall we go?

1 comment:

Mr. Fashion House said...

excellent post (as usual).

Concrete houses are the way to go! better for earthquakes and for fires, last a long time, and due to new developments can be self cleaning and carbon offseting