Sequoia Park Study Tackling Pollution

Times Staff Writer

Scientists from throughout the nation are here vacuuming a lake bottom, flying tethered balloons and conducting other experiments in the most comprehensive long-term air pollution and acid rain survey in any of America’s national parks.

The 10-year study, in its third year, is the biggest interdisciplinary ecosystem research project in California and one of the largest in the nation.

Sixty scientists from several University of California campuses, the National Aeronautics and Space Administration, the U.S. Forest Service, the National Acid Precipitation Assessment Program, the U.S. Geological Survey, Caltech, Arizona State University, Colgate University and Southern Florida University are in and out of the park throughout the year conducting experiments.


The California Air Resources Board is providing 80% of the $750,000 annual budget for the study.

“This is an opportunity to begin, at last, doing what should have been done years ago,” said Boyd Evison, 52, superintendent of Sequoia for the last five years and recently assigned director of national parks in Alaska.

“We are developing base-line information on the health of the ecosystems in Sequoia National Park as they are today, before they suffer severe damage. Our biggest immediate concern to the park, itself, is the potential threat to the giant sequoias, the largest living things on Earth.”

A curtain of brown smog from the San Joaquin Valley, with pollutants from as far away as Los Angeles and San Francisco, often drifts up the mountains and into the park.

Some Damage Evident

Some trees in the park have shown evidence of decline in recent years. For example, the needles of ponderosa and Jeffrey pines have been turning yellow from ozone.

“So far we have documented that there is acid precipitation falling in the park; that we do have significant levels of other types of air pollution,” noted David J. Parsons, 38, coordinator of the project and one of two research scientists permanently based in Sequoia.


“All the precursors for a serious acid rain problem are here. But the real question is whether it could become a severe problem within the next few years or in coming decades,” he said.

David Graber, 37, also a research scientist in the park, described more than 20 ongoing projects, including soil chemistry studies, tree-ring analyses to determine what effects pollutants have on tree growth, watershed research, plant physiology, snow hydrology and snow chemistry.

At Lake Emerald, divers collect algae, aquatic plants, fish and bottom sediment for study.

Difficult Diving

“We literally vacuum the bottom of the lake in 33-foot dives,” explained Roland Knapp, 20, a University of California, Santa Barbara, aquatic biology student and diver at the lake last summer. “Diving at 9,000-foot altitude is tricky. Maximum diving time at the lake is an hour--compared to two hours at sea level--because of nitrogen levels in our bloodstream.”

Frederick Shair, a Caltech professor of physics and an atmospheric scientist, recently released sulfur hexafluoride gas into the air near Visalia, simulating the flow of pollutants in prevailing winds. He mapped the movement of a plume of test gas over the mountains as it traveled in excess of 20 m.p.h.

Scientists from UC Davis sampled pollutants with tethered balloons.

In a meadow near Lodgepole, U.S. Forest Service scientists are checking the effects of ozone on giant sequoia and black oak seedlings by pumping pollutants into 10 eight-foot-high, six-foot-wide plastic chambers protected from roaming bears by electric fences.

Four national parks have long-term acid rain and ozone monitoring projects as part of the National Acid Precipitation Assessment Program. They are Sequoia, Isle Royale in Michigan, Rocky Mountain in Colorado and Olympic in Washington.


But the Sequoia project is the most comprehensive because of support by the state Air Resources Board.