Wildfire Q & A

Whatever happened to Smokey Bear?

The original black bear cub that was named Smokey (he was found, somewhat singed, in the ashes of a wildfire) long since went to that great hibernation den in the sky, or wherever bears go when they die. This question is posed for a different reason, to raise the issue of Smokey’s legacy.

That legacy, of course, is fire prevention. To the extent that this applies to fires caused by careless people, Smokey was right on. But, until recently, the message was taken further, to prevention and suppression (insofar as was possible) of all fires.

It is now recognized that wildfire is a natural process, one that is important to the health of forest and grassland ecosystems. However, because people are moving in ever greater numbers to areas outside cities, it’s necessary to be cautious about the use of fire as a management tool, whether the fires are “natural” or intentionally lit. Recent (May 2000) events on the North Rim of the Grand Canyon and in Northern New Mexico underscore this dramatically.

What’s wrong with fire suppression?

As discussed briefly in the wildfire overview, decades of fire suppression has led to an accumulation of “ladder fuels” in vast areas of the Southwest’s forests. This means that when fires are started in these forests, whether by people or nature, they tend to burn hotter and faster than they would in the absence of these ladder fuels. So they’re harder to get under control and more dangerous, particularly when they start near areas where people live.

Fire suppression isn’t a bad idea, but it needs to take into account this aspect of fire behavior.

So what’s to be done?

One option, of course, is to do nothing, and the problem will eventually take care of itself. A fire will get started somehow, and the excess fuels will be burned up. One problem with this approach is that the excess of fuels will tend to lead to a stand-replacement fire, in which the mature trees will also get burned up in the process. This is something that would tend not to happen if a low-intensity ground fire were to occur in a forest without the ladder fuels. Another problem is that other things, such as houses, could get burned up in the process as well.

Another option is to figure out how to remove the ladder fuels without burning the rest of the forest. One way to do this is to cut them down and remove the slash, either by wintertime burning (when a fire is unlikely to spread), by grinding it up with an industrial-strength chipper, or by hauling it out. Each of these methods has its positives and negatives, and the trade-offs among them are a source of controversy.

But if something along these lines isn't done, the “do nothing” option will be chosen by default, and we can look forward to more situations such as the May 2000 firestorm in Los Alamos, New Mexico.

Aren’t crown fires natural, too?

Historical forests tended to be a mosaic of species. Relatively small stands of mature trees were separated by grassland containing widely separated, single mature trees. When crown fires did occur, they didn’t tend to spread over such large areas as they can now.

Another way to think of this is in terms of biodiversity. In present conditions, there is a tendency for the pine and mixed confier forests of the Southwest to be biological deserts—the ground is covered with pine needles instead of grass; relatively few species of trees exist, most in stunted condition. Historically, a mosaic of clumps of trees, grasslands, and the mixture of species supported a far wider variety of plants and animals.

When crown fires did occur, their area was limited and the re-succession process was helped by the existing mix of species in the surrounding area.

Under present conditions, crown fires tend to be so catastrophic that it’s necessary to re-seed the burned areas by hand. And sometimes the soil is sufficiently sterilized that even this process takes several years, during which time erosion is uncontrolled.

Natural, but deadly

Photograph copyright ©1999, Corel Corporation. Smokey Bear image is public domain. All other material copyright ©2000, 2010 Howard P. Hanson.