California's Threatened Giants

Magnificent redwood trees stand high above California's coastline. Redwoods are the world's tallest trees; some are taller than the Statue of Liberty. They are also some of the oldest trees, up to 2,000 years old. Some scientists are concerned about a disease that is threatening these ancient giants. It is called sudden oak death.

Spreading Along the Coast

The disease has scientists alarmed. First identified in 1995, sudden oak death has spread along hundreds of miles of California's coastline and now appears in southern Oregon. In addition to attacking oak trees, it has spread to redwoods, Douglas firs, and other types of trees and shrubs. One of the worst outbreaks of the disease has occurred at California's Pfeiffer Big Sur State Park.

The Disease Identified

Scientists recently discovered what is causing the disease. It is a fungus that causes oozing red blobs to grow on diseased oak trees. On younger redwoods, it dries up leaves and kills sprouts. According to scientists, redwoods are hosts for the disease. A host is an organism, or form of life, on which another organism lives. A common example of a host is a dog with fleas: the dog is the organism on which the other organisms (fleas) live.

The oak disease first showed up in the Netherlands in 1993. The spread of this disease could pose a threat to the redwoods' ecosystem, or environment where plants and animals live together. Scientist David Rizzo said that anytime you have a strange organism, there is cause for concern.

In 1904, a fungus from Asia began killing chestnut trees in New York. Over the next 50 years, the disease killed about 3.5 billion trees and almost wiped out an entire species. Scientists want to prevent this from happening to the rare redwood trees.

“We have to get familiar with the symptoms and the treatments,” said another scientist, “because we don't know how much farther it will spread.”