|
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
By SUSAN WARREN
Page A1
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 Dixie 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 susan.warren@wsj.com
|
