Earth, Where Are You?
Earth, Where Are You?
Earth Day finds professor searching for what's left
Scalise, Public Affairs
How much American soil remains in a pristine, natural state?
As Earth Day approached, a Berkeley soil scientist had been commissioned by a leading scientific foundation to find out.
He hopes to identify soils he considers relicts in danger of extinction unless efforts are made to preserve tracts of land. A relict is a plant or animal species living on in isolation in a small local area as a survival from an earlier period or as a remnant of an almost extinct group.
"I always thought the time you retire is when you worry about preserving landscapes," said Professor Ronald Amundson, 45, "but I guess I was wrong."
Amundson conceived of the idea of the national virgin soil study when he was asked to write an essay on the subject for a geology anthology called "The Earth Around Us: Maintaining a Livable Planet" to be officially published on Earth Day 2000, by W. H. Freeman & Co. In researching his chapter, he discovered that quantified data on the nation's undisturbed soil were unavailable.
"It's not at all discussed by the U.S. Department of Agriculture," he said. "I was surprised and pleased that geologists were interested in this and wanted more information."
Many endangered soil types are in what Amundson calls "subtle landscapes," annual grasslands, desert, tall grass prairie.
"These are not the kind of places that have typically inspired national parks, but they are important to preserve regardless of whether they have mountains or valleys or stunning rock formations," he said. "Besides the historical record, the soils harbor a multitude of microorganisms that we have barely scratched the surface of understanding. Some early antibiotics came from soil microorganisms.
"We would be bold to suggest that in only just the little time we've studied these soils we've got all the answers and we don't need these soils anymore," he said.
To begin the first-ever national study, Amundson joined up with Berkeley ecosystems professor Peng Gong, who specializes in geographical information analysis. The Kearney Foundation of Soil Science provided about $30,000 for the first year of the study.
The two professors are taking the USDA's national digitized map of original soil surveys and overlaying it with current maps of agricultural and urban growth.
"We'll see what's left when we subtract out human uses of the landscape," Amundson said. "We're going to get numbers on things we intuitively knew. My impression is that there is a very small pool left of some very important soils."
Amundson is a good choice for the task. He and his colleagues have been studying some of the oldest soils anywhere. A series of terraces in Wyoming told them, for instance, that summer monsoons once blew off the Great Plains over high desert. Other soil studies have revealed that global atmospheric carbon dioxide buildup began not with the burning of fossil fuels, but with the conversion of prairies and woodlands in the United States and Europe to farmland.
For most of his career, land preservation was not an area Amundson worked much in. For almost 20 years, he has been quietly delving into complex soil chemistry such as carbon cycles and light-isotope geochemistry.
"Soils," he said, "are not usually considered part of the earth sciences."
Traditionally, soils have been the domain of agriculture, where they were studied as the medium to grow crops. Amundson hopes to change all that, bringing the study of soil to the wider attention of geology and the earth sciences, where it deserves a rightful place, he said.
The University of California has its own important role to play in soil preservation, Amundson said. One of the most interesting natural landscapes left in California is in and around the site of the new UC Merced campus, he said. The area has some of the last sweeping vistas of vernal pools left in the great valley, and the most ancient soils in California, 3 million-year-old relicts. Amundson said at first he was quite disturbed about the location of the campus.
"But now I think maybe it is an opportunity to gather interest in the area before it disappears under urban development," he said. "Maybe it presents an opportunity to set aside some of the land and keep it forever. It could be sort of an outdoor classroom, a natural lab. I think it is very interesting that UC faculty, particularly the biologists, are beginning to pick up on the fact that this is a very precious area."
To describe how soil can become extinct, Amundson told the story of the infamous San Joaquin soil, which in 1997 was named the official California "state soil." The most prevalent soil in the state, it has been long loathed by farmers and homeowners alike for its "hardpan," a layer of impenetrable mineralized clay three feet below the surface.
"We've spent a century first trying to blow it up with dynamite and then rip it open with tractors," Amundson said. Now, undisturbed San Joaquin soil is so rare, Amundson said he can hardly find it. When it was named the state soil, after most of it already was destroyed, even the San Francisco Examiner couldn't resist an ironic stab at it.
"Glory doesn't come along every day for dirt," the Examiner said. "...Let's just hope that the Official State Dirt doesn't emulate the Official State Animal, the grizzly bear, which hasn't been seen in California since 1913."