Sudden Oak Death in Doug fir, Redwood www.sfgate.com Return to regular view

Richard McGuiness armich at cox.net
Thu Sep 5 12:58:56 EST 2002


        www.sfgate.com        Return to regular view
California rushes to protect redwoods
Davis seeks Bush aid as tests confirm sudden oak death
Peter Fimrite, Chronicle Staff Writer
Thursday, September 5, 2002
©2002 San Francisco Chronicle.

URL:
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2002/09/05/MN244379.DTL&typ
e=science



The alarming revelation that California's magnificent redwoods are infected
with the deadly plague that has ravaged oak trees hit politicians and
forestry officials like a bolt of lightning Wednesday, prompting a request
by Gov. Gray Davis for federal aid.

The enigmatic disease known as sudden oak death has been found in numerous
redwood saplings and sprouts in five different counties and also in Douglas
fir trees in Sonoma County.

The presence of the microbe, whose scientific name is Phytophthora ramorum,
in redwoods has been suspected since January, but it had not been confirmed
in tests until now.

It means two of the state's most valuable timber resources could be in
danger from a scourge that has already laid waste to tens of thousands of
black oak, coast live oak and tan oak trees from Monterey to the Oregon
border.

Alarmed by the "grave risks" posed by the fast-spreading disease, Davis sent
a letter to President Bush on Wednesday asking for $10 million to combat the
disease.

"The implications of this disease are enormous," Davis wrote, "including a
major change in the environment and landscape of California, severe economic
dislocation and an increase in fire danger."


LETTER FROM BOXER
U.S. Sen. Barbara Boxer also sent a letter to Bush, urging him to release $5
million in emergency funding for sudden oak death that has been held up in
budgetary proceedings. As of now, only $2 million is budgeted this fiscal
year to fight the disease.

Taken together, redwood and Douglas fir make up more than 50 percent of the
approximately $3 billion-a-year value of wood harvested in the state.
Douglas fir is an even bigger industry in Oregon and Washington, where state
officials are closely watching developments in California.

"Ninety-five percent of the redwood harvested in California and 45 percent
of the Douglas fir come from areas of infestation," said Louis Blumberg,
spokesman for the California Department of Forestry and Fire Protection. "So
the implications are quite grave."

The California Department of Food and Agriculture announced immediate
restrictions on the movement of redwood and fir products from the 12
counties in the official "zone of infestation."

That means, among other things, that the bark must be removed from all
lumber moved across county or state lines and a county agricultural
commissioner must inspect the load.

The regulations, which were in existence for infected wood before the latest
findings, are currently under review by state and federal officials.


POSITIVE OUTLOOK
But with the effect on their harvests still unknown, timber industry leaders
preferred to put a positive spin on the new revelations.

"The key point here is that there is no evidence of this on commercial
timberland," said Donn Zea, president of the California Forest Products
Commission. "We believe the impact will be minimal if rational and
reasonable measures are put in place."

Coastal redwoods, the world's tallest trees, have long drawn tourists to the
magnificent California groves. The ancient trees once grew as far away as
Russia, but were killed off by the last ice age in all but the coastal fog
belt in California and southern Oregon, according to forestry experts.

The trees, which can reach heights of more than 350 feet and live as long as
2,000 years, are the fastest-growing softwood in North America, regenerating
quickly as shoots sprout off the cut stump.


NOT MANY ANSWERS
Despite the ominous tone of many of Wednesday's pronouncements, the presence
of the microbe in redwood and Douglas fir brings up more questions than it
answers.

So far, 17 plant and tree species have been identified as being susceptible
to the disease, but most of them do not appear to be dying from the
infections.

Studies by Matteo Garbelotto, a forest pathologist at UC Berkeley, and David
Rizzo, a professor of plant pathology at UC Davis, seem to show that ramorum
spores congregate on the leaves of bay laurel trees and spread to other
species through wind and rain.

The concern about redwood trees began in earnest a year ago, when dead
sprouts were seen coming out of redwood tree trunks at Pfeiffer Big Sur
State Park in Monterey County.

DNA tests and other experiments were then conducted on saplings in Jack
London State Park in Sonoma County and Henry Cowell State Park in Santa Cruz
County. Diseased sprouts in Muir Woods, Marin Municipal Water District
property on Mount Tamalpais, and at UC Berkeley, Big Sur and Armstrong
Redwood State Park in Sonoma County were also tested.

Rizzo said diseased Douglas fir saplings from a private reserve east of
Santa Rosa were also tested. All of the tests came back positive.


REDWOOD INFECTION
"At every sight we went out to, we found evidence of the disease on
redwoods," Garbelotto said. "In contrast, infected Douglas fir saplings were
found at only one site -- in Sonoma County -- but they seemed to show a
stronger reaction to infection."

Given the staggering death rate among oak trees -- where the disease was
first noted, leading to the sudden oak death moniker -- Garbelotto and Rizzo
fear the deadly microbe might find another mortal victim if allowed to
spread.

Garbelotto and Rizzo were quick to point out, however, that the infections
were only in saplings and sprouts and there is no evidence yet that the
disease can actually kill grown trees.

The symptoms were primarily found in the needles and small branches of the
redwoods. The infected Douglas fir were surrounded by infected bay laurel
trees, and the two scientists speculated that the reaction there may be
unique to that site.

"It does seem to be fairly common in redwoods, but redwoods are pretty
hearty in terms of susceptibility to disease," Rizzo said. "No large Douglas
fir or redwoods have died, and based on what we have now, I would say none
will die from this pathogen.

"But we have a lot of unknowns," he continued. "We really don't have a good
sense of the progression of the disease over a period of years."

Ken Bovero, owner of Marin County Arborists, said he believes that the
disease is responsible for the death of two redwood trees in Mill Valley,
one of which was tested after it was cut down.

Garbelotto and Rizzo said that although that tree contained ramorum spores,
it also had numerous other diseases and they could not determine what killed
the tree.

"I don't think we will see the mortality rates we have seen with live oak
and tan oak, but there are a number of areas in Mill Valley alone where the
redwoods look horrible," Bovero said. "Stands of redwoods are declining.
They are showing a lot of dieback."

The biggest fear is that oaks -- and now, possibly redwoods and Douglas
fir -- will go the way of the American chestnut, which was essentially wiped
out in the early part of the century by another phytophthora.

Rizzo said the California blight, which is related to the organism that
caused the Irish potato famine more than 150 years ago, is most similar to a
disease now ravaging trees in Western Australia in that both diseases have
numerous hosts.

Even if the disease doesn't kill mature redwoods, it could affect
regeneration by killing the ever-present sprouts that grow on stumps, Rizzo
said.



----------------------------------------------------------------------------
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Species affected by sudden oak death
Alarmed scientists are now finding the fungus, Phytophthora ramorum, that
causes sudden oak death in Douglas fir and coastal redwoods. Although there
have been no observed deaths of these trees from phytophthora, scientists
are finding it disturbing that phytophthora has crossed over to different
types of trees and plants (16 of these occur in California). ÐThe first
reports of sudden oak death disease began appearing in 1995 in the dying oak
trees of Marin County. The disease has now killed tens of thousands of oaks
and tan oaks.

Symptoms

Early symptoms appear as a bleeding canker; burgundy red to tar black sap
oozes on the bark surface.

Leaf symptoms first appear. New leaves droop or turn yellow to brown.
Bleeding similar to live oak appears on bark surface. .

Current host list

-- California black oak

-- coast live oak

-- Shreve oak

-- tan oak rhododendron

-- California bay laurel

-- big leaf maple

-- madrone

-- manzanita

-- huckleberry

-- California honeysuckle

-- toyon

-- California buckeye

-- California coffeeberry

-- Arrowwood (in Germany, United Kingdom and the Netherlands)

-- coastal redwood

-- Douglas fir .

Non-oak tree symptoms

Madrone

Purplish leaf spots and stem cankers

Rhododenron

Canker on leaf and shoot dieback

Buckeye

Leaf spots .

Areas found to have sudden oak death pathogen infected redwoods and Douglas
fir

Jack London State Park (redwood saplings)

Armstrong Redwood State Park (redwood sprouts)

Area east of Santa Rosa (Douglas fir)

Marin Municipal Water District (redwood sprouts)

Muir Woods (redwood sprouts)

U.C. Berkeley (redwood sprouts)

Henry Cowell State Park (redwood saplings) Big Sur (redwood sprouts)

Big Sur (redwood sprouts)

Sources: The Center for the Assessment and Monitoring of Forest and
Environmental Resources at UC Berkeley. Images courtesy UC Berkeley;
Phytophthora image by Dave Rizzo; Oak tree symptom photos by Dr. Pavel
Svihra

Chronicle Graphic

E-mail Peter Fimrite at pfimrite at sfchronicle.com.

©2002 San Francisco Chronicle.   Page A - 1
Comment: Not only is a large amount of timber dollars threatened, but our
very tools for forest and waterdhed recovery could be in jeopardy. Rich
McGuiness






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