Every summer, news reports portray firefighters struggling heroically to
contain wildfires as they rage out of control in the American West,
threatening homes and sometimes lives.
Most of us assume that
these giant conflagrations, often started by lightning, are a normal
part of the natural cycle. That's partly true—and partly wrong.
The worst fires tend to occur where enormous amounts of dead tinder have accumulated in thick stands of trees. In much of the American West, neither the trees nor the tinder are "natural." They are there because something else is missing. That something is the buffalo.
Only a few centuries ago, much of what today is scrubby, flammable woodland in the Mountain West and the Great Plains was grassy parkland. Vast herds of buffalo, roaming between Canada and Mexico, kept the grasslands open. The grazing of buffalo, combined with foraging by deer, pronghorn and many other animals that benefited from the bulldozing activities of buffalo herds, prevented dead vegetation from piling up in heaps that could fuel cyclonic fires.
Grass fires on the premodern prairie seldom had the intensity of today's worst wild fires—for the simple reason that the fire had to compete with the herbivores for food.
Today, however, much of the former Western grassland has mutated into forest. When prairie is fenced and bison are removed, in the absence of extensive grazing by cattle, trees that were formerly confined to riverbanks and creeksides rapidly invade and colonize the entire landscape.
Deer, the only remaining large herbivores in much of the region, cannot prevent the build-up of mounds of leaf litter and wood that can energize colossal wildfires.
Obviously reintroducing the buffalo and the pronghorn to settled areas is out of the question. But much of the land of the West is in federal parks, and already off-limits to development.
The federal government could also encourage landowners to allow unnecessary farm and ranchland to revert to wilderness, either in public or private hands, and could accelerate this reversion of land by slashing wasteful federal agriculture subsidies, which harm the land even as they cheat the taxpayer.
Already the buffalo—which was nearly extinct a century ago—is making a comeback in the few surviving pockets of American grassland. Federal, state and private land managers ought to give serious consideration to reintroducing buffalo in other large wilderness areas where grassland, in only a few generations, has been replaced by invading—and highly flammable—thickets of trees.
As a result of this, the frequency and intensity of wildfires would diminish as much of the North American landscape resumed its traditional appearance. "Fire behaves much like mega-herbivores do—consuming dry and coarse vegetation," the paleontologist Tim Flannery writes in his recent natural history of North America, "The Eternal Frontier."
Flannery, an Australian, also endorses an idea proposed a few years ago by the American naturalists Paul Martin and David A. Burney: Restore the elephants to North America.
