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Wildlife's Trial by Fire Is Just Beginning

November 02, 2003|Kenneth R. Weiss and Steve Hymon | Times Staff Writers

For Jim Bauer, it was a search for life in the valley of death.

Charred remains of scrub jays and woodpeckers and rabbits littered the ground. The towering pines were gone, so were the oaks. Yet as the wildlife biologist moved through the eerie stillness of the smoldering state park in the mountains east of San Diego, he picked up a faint, telltale signal of hope.

And then another and another. All told, seven of 11 deer outfitted with radio collars were alive in Cuyamaca Rancho State Park. Just outside the park, two of six mountain lions equipped with transmitters were on the prowl.

"Looking at that fire, I wouldn't have guessed that any survived," said Bauer, a wildlife biologist who is participating in a UC Davis study of lions, deer and bighorn sheep in the area. "Mountain lions need a huge chunk of country, and when you have this fragmented and altered habitat to begin with, a big fire like this will have some impacts."

Although wildfires are part of the natural cycle in Southern California, scientists are worried about the cumulative impact of so much scorched earth on top of other stresses: the steady advance of urban development, pollution, invasive fire-prone plants, persistent drought and climate change.

With all of these strains on the environment, what will grow back now that wildfires have wiped the landscape clean? Will pine forests be replaced by chaparral or oak trees, as some experts suspect? What will be the impact on Southern California's ecological health and how will it affect humans?

A change in the forest canopy can rob animals of shelter and nourishment. Without pine trees, for instance, ground temperatures can rise and the moist forest floor can dry up, making it inhospitable for some creatures.

One team of scientists is studying how the plume of smoke sent toxic heavy metals and pesticides sifting down with the flurries of ash throughout Southern California.

They expect, as past studies have suggested, that tons of copper, lead and zinc particles will get washed into streams, rivers and the ocean, poisoning aquatic life and edging their way up the food chain.

"Aside from the obvious effect on everyone's breathing, these toxic compounds fall out of the sky, wash down and affect aquatic life," said Keith D. Stolzenbach, a UCLA professor of civil and environmental engineering. He noted that copper is so toxic to fish that it's used to clean out ponds and painted on boat hulls to keep barnacles from growing. Lead, which tends to sink to the ocean floor, can work its way up to humans who eat fish.

Another area of concern scientists plan to investigate is what it means to burn so many holes in the region's umbrella of foliage. Across the burned landscape, the holes add up to a gap bigger than Rhode Island.

"Trees are like sponges, filtering pollutants out of the air, intercepting rainfall" and helping replenish groundwater supplies, said Greg McPherson, director of the U.S. Forest Service's Center for Urban Forest Research at UC Davis. "Burning up those trees is like losing one of your lungs. The air quality isn't going to be the same. The runoff isn't going to clear. The system is going to be perturbed."

It is wildlife that may have taken the greatest hit.

"Think of it as a major refugee problem for many of these species," said Mark Borchert, the chief U.S. Forest Service ecologist for Southern California. "Some of these burns cover thousands of acres, and there is no place for some species to flee."

As fire swept across Summit Valley in the San Bernardino Mountains last week, rabbits and other animals were on the run, some dodging headlights, in their panic to escape the curtains of flame.

In Lake Arrowhead, kangaroo rats congregated on the only ground not on fire -- the roadway -- only to be run over by firetrucks and TV news vans. In San Diego County, firefighters found a deer burned to death near a barbed-wire fence it may have sought to hurdle to flee the flames. Most animals tend to persevere. They evolved with this fire-prone landscape and have strategies to make it to safety or burrow deep enough underground to escape the scorching heat.

Some profit from fires. Throughout the week, red-tailed hawks and ravens could be seen over burned brush, diving for prey exposed by lack of cover.

Yet, the fate of animals deeper in the backcountry remains largely a mystery.

Researchers who had spent years tracking habits of mountain lions, bighorn sheep and deer began fretting -- sometimes unnecessarily -- that years of study had gone up in smoke.

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