Park Service Will Let Nature Take Its Course

Wildfires continue to smolder in parts of Yosemite, but the National Park Service already has mapped out the basic plan on what to do with those parts of the park ravaged by flame: Nothing.

Unlike the U.S. Forest Service, which responds to fires by swiftly clearing out fire-killed trees and planting new ones, the Park Service sees wildfire as just another natural forest process that is best left alone for scientists and park visitors to study and observe.

As with other recent fires in national parks--most notably the Yellowstone conflagration of 1987--natural grasses will sprout in Yosemite’s burned areas, and bushes, shrubs and eventually trees will follow. With very few exceptions--where endangered species are threatened or firefighters have cut unnatural fire breaks--it will happen without help from humans.

After all, said Park Service officials, that is their mandate--to protect and preserve the national parks. The Forest Service and other big land management agencies must consider the production of timber and other resources in their planning.

“National parks are managed under procedures that protect and preserve all native species,” Park Service spokesman George Kyle said. “That is, they are managed so that in 100 years, we should have the same plants and animals there as before man arrived or before the area was used very heavily.”

A combination of the desire to leave parks in the natural state and lack of desire to use parks to produce timber encourages park managers to accept fires and the role they play in clearing out dead material and promoting new life.

John Dennis, Park Service wildlife and vegetation branch chief in Washington, said it is not even wise to think in terms of “repairing” fire damage.

“It’s not necessary to repair because it’s not broken,” he said. Fire “is just the next phase in an ever-changing process. The system is geared up to have fire every so often, and some plant and animal species have adapted to it and actually need it to thrive.”

Indeed, he said, watching an entire forest ecosystem rise from the ashes of a wildfire is a precious opportunity to people who understand the process.

“You could see this . . . not as a disaster,” Dennis explained, “but as a unique opportunity for people of our generation to see a process we won’t be able to see again for another three or four generations.” Until, that is, the parks again become so lush that they can burn once more.

It is still too early for Yosemite officials to know exactly what condition the affected areas will be in once the fires are fully extinguished, but specific problems could cause the Park Service to deviate from its policy.

If, for example, there is poor soil on some of the slopes that have burned, crews could be called in to install erosion-control devices, such as berms and trenches to control rain runoff, or seed the areas with native grasses to stop rain from washing away the soil.

Without such measures, hillsides could be stripped of their soil, making it hard for vegetation to take root, and rivers could be clogged with silt that can kill rare fish or make it impossible for them to reproduce.

“In most cases, these areas have not been disturbed by human activities,” said Dennis, “so the soil surfaces should still be fairly tolerant of erosive activity.”

Burned areas are not as attractive to most park visitors as the dense, old-growth forests that were lost, but the process of natural forest regeneration can itself be a tourist attraction, as it was in Yellowstone over the last two years.

“Yellowstone has underscored the fact that (burned) areas tend to restore themselves very quickly,” Kyle said. He said botanists expect scorched lands to be covered with grasses and legumes as early as September or October.

Trees will take much longer--a number of decades--to reappear in the same size and number, but reseeding will start again this year in areas where fires were limited to the dead limbs and leaves on the forest floor.

As with any outbreak of wildfires, the recent Yosemite blazes will also give scientists new insight into the regeneration process.

“It’s a real opportunity to learn more about our natural systems,” Dennis said.