WALL STREET JOURNAL. Friday
October 13, 2006
God Can Make a Tree, But Olaf Ribeiro Can Save Its Life
Plant Pathologist Roots Out The Causes of Disease; It Just Takes Spade Work
OLYMPIA, Wash. -- Plant pathologist Olaf Ribeiro crouched beneath the spreading evergreen branches of a sequoia tree on the state capitol grounds and peered into the underground world. A colleague had just used an "air spade" to blast away dirt with a jet stream of air, uncovering the dense network of shallow roots at the base of the tree. Dr. Ribeiro immediately spotted a killing fungus eating away at the roots. "We have to save this tree!" he told the team of tree experts gathered around.
"I worry that future generations will know of giant old trees only by the stumps preserved in museums," he says. "I want to save old trees so that people can stand at the base of them and say, 'My God, look what nature can do.'"
Trees are dying in large numbers in cities all over the country. American Forests, a nonprofit organization in Washington, D.C., that fights for preserving trees in urban areas, says satellite reconnaissance shows metropolitan areas in the eastern U.S. have lost 30% of their tree cover in the past 20 years. It argues that about 635 million trees need to be planted in cities nationwide. Urban tree loss, due mainly to developmental sprawl, contributes to the decline in air quality as well as flooding problems in metro areas. Tree roots and the soil they are in soak up excess water, and trees consume carbon dioxide that would otherwise contribute to greenhouse gases.
Dr. Ribeiro sees the loss of trees as unnecessary. In fact, he is trying to prove that trees can live forever given the right conditions. As an expert in plant diseases like the fungus that caused the 19th-century Irish Potato Famine, Dr. Ribeiro believes the key to tree longevity is in the dirt.
Trees have evolved in sync
with a complex underground world that nourishes them and keeps them
healthy. Farmland cultivation, construction, foot traffic and pollution
have upset the balance, cutting short trees' lives, argues the energetic,
68-year-old Dr. Ribeiro, who runs a private lab near Seattle that specializes
in diagnosing diseases in crops and trees. He believes that if the original
microbial activity around the tree could be duplicated, "There's
no reason the tree shouldn't go on living."
Even death is just a passing phase for many trees, he says. A tree can go on living for centuries, through a rotting stump that nourishes new life, or through roots and branches that sprout saplings.
Arborist Neville Fay, of Britain's Ancient Tree Forum, calls these perpetually regenerating life forms "phoenix trees." He believes that letting old trees die destroys the chance to study, and learn more, about the oldest life forms on the planet. Ancient trees are colonized by micro-organisms that may date back thousands of years. "The tree is an ark that carries these organisms through time," he says.
Mr. Fay and Dr. Ribeiro are joining with others to form interdisciplinary teams that can diagnose problems with dying trees and keep them alive many years longer.
To be sure, saving individual old trees is criticized by some tree experts, who deride it as "geriatric forestry." Rescues are labor-intensive and expensive, at prices that can run up to $30,000 per tree. Eric Oldar, who works for the California Department of Forestry, worries that too much focus on single trees could detract from the larger problem of cities eating away at the nation's forest canopy. The effort and money to save one old tree might be better spent protecting younger, more productive trees in the environment, he says.
Whether to save old trees comes down to measuring their value, and that's a tough call, says David Nowak, a forestry expert with the USDA Forest Service in Syracuse, N.Y. "Yes, we can keep it going. But what are you getting in return?" he asked. "Is that tree actually growing? Or is it just hanging on?"
Forestry experts agree that some old trees -- especially those with historical significance -- are worth saving at almost any cost. Deborah Gangloff, executive director of American Foresters, says such trees can be "living landmarks." "It's like paying to make sure the Liberty Bell or the Bull at Wall Street are maintained," she says.
Dr. Ribeiro believes people pay too much attention to what they can see, so when a tree appears to be dying, they rush to cut it down before it falls and causes damage.
Lately, he has focused his attention on the venerable old trees of the state capitol in Olympia. In 2003, he got together with Rob Lloyd, owner of Lloyd's Arboricultural Consulting in Battle Ground, Wash., and Neal Wolbert, president of Landscape Health Care in Olympia, to save a dying Norway Maple at risk of being cut down.
The team relies heavily on the air spade, a long-handled tube with a half-moon shield connected to an air compressor. The tool, designed to help excavate trees for moving, blasts away the dirt with high-pressure air that leaves roots undamaged. It allows Dr. Ribeiro to pinpoint root problems with surgical precision.
With a clear view of the roots of the giant maple, Dr. Ribeiro and Mr. Wolbert were able to identify and treat the area where fungus was devouring the roots, then backfill with a special prescription of nutrient-enriched soil and mulch. Now, the tree is flourishing.
Air-spading at the base of an ailing redwood, used as the state Christmas tree, revealed that small roots circling the tree were choking larger roots. "This is radical stuff," acknowledged Mr. Wolbert, as Mr. Lloyd fired up a chain saw to cut away the offending growth.
The team rescued another Norway Maple nearby. Mr. Lloyd designed a steel pole to suspend cables for supporting the tree's huge, majestic limbs, which had been weakened by rot and posed a risk of falling on passersby. Some arborists might have recommended cutting it down. But now, "this one will go forever," said Dr. Ribeiro.
Finally, the team noticed a young sequoia, planted in 1980 in honor of Dixy Lee Ray, Washington's first woman governor. It needed help. Though the tree looked green and healthy above, mushrooms sprouting at its base signaled trouble below. Air spading revealed extensive, treatable root rot that was spreading to another nearby tree. "It's a little like 'CSI,'" said Dr. Ribeiro, summing up his day's work.
Write to Susan Warren at email@example.com