ECOLOGICAL STUDY REVEALS DAMAGE TO SIERRA RANGE.

Byline: Kathleen Holder Associated Press 

The Sierra Nevada got its most extensive checkup Friday, and the diagnosis was grim: The spectacular mountain range is being depleted by a host of plagues including overgrazing, logging, urbanization and smog.

But scientists who conducted the $6.3 million assessment concluded the prognosis could be hopeful - with better land use and environmental protections.

Among the recommendations by the Sierra Nevada Ecosystem Project are creation of old-growth forest reserves, use of prescribed fires, and an ecosystemwide approach to land management.

The 3,200-page study, commissioned by Congress and written by 107 scientists, is intended as a tool for policy-makers as they chart the future for the Sierra Nevada.

Among its findings:

The climate may be getting drier in the Sierra, which is the source of much of California's water. ``Periods of century-long droughts have occurred within the last 1,200 years and may recur in the near future.''

Rangelands still show consequences of grazing, which was unchecked until the early 1900s and in some places caused irreversible ecological damage.

More than any other human activity, logging has increased the risk and severity of fires by removing the cooling shade of trees and leaving flammable debris.

Old-growth stands make up 7 percent to 30 percent of the forests, depending on the forest type. National parks have four times as many of the ancient trees as national forests.

Unlike the Pacific Northwest, the Sierra is not being heavily clear-cut. Clear-cuts larger than 10 acres are uncommon, and early large clear-cuts have been reforested.

Three plant species and three animal species have become extinct in the Sierra, and many more are at risk. Frogs and other amphibians have severely declined in numbers.

Quality of life for people in the Sierra varies widely - with nearly 19 percent of the population living in poor communities and 16 percent living in well-off towns.

Timber, agriculture and mining play declining roles in the local economies, while recreation and tourism have become more important. Retirees and people who commute to jobs elsewhere account for more than half the personal income.

Air quality ranges from some of the cleanest in the world, in the northern Sierra in the winter, to some of the nation's dirtiest, in the southern Sierra in the summer.

The report especially has implications for the U.S. Forest Service, which financed the study.

The Forest Service had delayed release of a new plan for logging in national forests in the Sierra to make sure it was consistent with the report.

``We simply don't know if there's anything in there that we missed. We haven't seen (the report) yet,'' said Matt Mathes, a Forest Service spokesman in San Francisco.

Environmentalists praised proposals to protect old-growth trees and use prescribed fires to aid the natural cycles of the forests.

``The timber industry has really tried to beat into the public that logging is the answer to reducing the risk of fire,'' said Jay Watson, regional director of the San Francisco-based Wilderness Society.

``But I think this report shows that it's a preposterous notion that we have to cut the forest down to save it from burning up.''

John Hofmann of the California Forestry Association said he didn't believe use of managed fires was practical.

``Of course, we need a product and you can't burn up your products,'' he said.