A disease that has devastated oak trees on the West Coast could spread to the vast oak forests of the South and East and wreak havoc on wildlife, biologists say in a new warning.

"There is a potential that the Eastern forests could be even more vulnerable to the disease than West Coast forests," says David Rizzo, a plant pathologist at the University of California, Davis.

Recent tests on seedlings show that pin oaks and northern red oaks - classic trees of Southern and Eastern forests - are susceptible to the swimming two-tailed fungus that apparently causes the fast­spreading disease. "It is possible that all red oak species are susceptible," Rizzo says.

A major loss of oak trees in Southern forests would create profound hardship on wildlife. Dozens of animal and bird species depend on acorns from oak trees to nourish them through the winter. In the spring, migrating songbirds depend heavily on the millions of tiny caterpillars that live on oak leaves.

"I hate to think what would happen if there was a big loss of oaks," says, Terry Johnson, head of the non-game wildlife section of the Georgia Department of Natural Resources.

The malady, known as "sudden oak death," was discovered in tan oaks in California in 1995. It has killed more than 200,000 tan oaks, coast live oaks, California black oaks and Shreve's oaks along the California coast and, more recently, in southwestern Oregon.  Rizzo said the oak die-offs have turned many once­forested slopes a desolate brown. As the hillsides lose trees, the soil loosens, resulting in massive erosion that drives silt into once crystal­clear trout streams.

The fungus believed to cause the deaths was previously unknown to science. It was discovered by Rizzo and fellow researchers with the University of California Research Team, which has been assigned to track down the cause of the disease.

Rizzo says the organism, dubbed Phytophthora ramorum, is related to the organisms that caused the Irish potato famine of 1845-50 and, in recent decades, the deaths of cedar trees in Northern California and southern Oregon, eucalyptus forests in Australia and oak forests in Mexico, Spain and Portugal.

The spores of the fungus have tails that propel them quickly through water. They enter through the bark of oak trees, possibly after the spores are splashed onto the barks by raindrops.

Once in the tree, the fungus produces chemicals that dissolve tree tissue, causing oozing sores in the bark. As the disease progresses, the tree becomes vulnerable to bark beetles, which burrow into the tree and kill it.

The recently discovered fungus probably was accidentally introduced into this country, possibly arriving on an ornamental plant, Rizzo says.

He and his colleagues surmise that the fungus will be lethal to mature northern red oaks and pin oaks. Seedlings of those trees died after being afflicted by the malady in the laboratory.

While tests on other oak seedlings have not been completed, Rizzo believes that all red oak species will prove to be vulnerable to the disease.

The disease is likely to be spread by dirt on cars and construction equipment, hiking boots and pets' paws. Even a stick of firewood brought back by a vacationer on the West Coast could spread the fungus.

"Preventing the movement of soil and wood will be critical to slowing the spread of the fungus," Rizzo says.  Complicating efforts to contain sudden oak death, however, is the discovery of the disease in commercial rhodo­dendron nursery stock. Oregon has imposed an emergency quarantine on nursery stock and oak firewood from California to slow the spread of the disease.

Until recently, experts had believed that oak species in Eastern forests were not susceptible to the fungus.  Environmental authorities in the eastern United States have not yet proposed any safeguards.

"Right now, we assume that trees in Eastern forests are vulnerable," Rizzo says. "It could be that there are some ecological differences in the East that could prevent the fungus from getting a niche there, but we don't know that."

Eastern forests already have been devastated by two other maladies: chestnut blight, which wiped out the entire American chestnut tree population in the last century, and Dutch elm disease, which killed millions of elms.