[Mike]

Experts mystified by dead-oak ‘curiosity’
Local residents are noticing a lot of oak trees dying suddenly and
with no obvious cause.

http://www.dailypress.com/news/dp-oaksaug11,0,4384686.story?coll=dp-
headlines-topnews

BY MIKE HOLTZCLAW
928-6479

August 11, 2005, 4:43 PM EDT

A few weeks ago, Betty Baker was backing out of her driveway in York
County when something looming over the garage caught her eye.

It was one of the old oak trees in her back yard, a familiar sight.
But this time, it looked different. She took off her sunglasses to
get a better look, and she realized that the leaves had all turned
brown, seemingly overnight.

“I saw that and said, ‘Oh my, that tree is dead!’ ” Baker
recalls. “It’s a gorgeous tree – or, at least, it was. It had been
fine, and then I looked up one day and it was dead.”

She started looking around and noticed other dead oaks in neighboring
yards. Glancing into the wooded area behind her home, she could
clearly spot dead oaks sitting amid the living ones.

Puzzled, she arranged to have the dead tree taken out of her back
yard. The workman was equally puzzled. He suggested that she leave
the tree up, at least temporarily, so someone could look at it and
figure out what was happening.

That’s where Jim Orban comes in. He is a horticulturist with the
Virginia Cooperative Extension, and Baker’s call was one of many he’s
received in recent weeks about oaks dying very suddenly. Today, he
and Rob Farrell – an arborist at the Virginia Department of Forestry
in Gloucester County – will visit Baker’s yard and other sites in
York County trying to learn more about what’s killing the oaks.

“It’s normal to get tree questions, but not as specific as these
were,” Orban says. “The thread that ran through them was the same:
Within a space of about two weeks, the trees had gone from solid
green to brown, without passing through any other stages in between.
That can happen sometimes with a maple or a sycamore, because those
are early-season defoliators, but you don’t see it with oaks.”

When he spoke with the callers, he found no obvious answers. There
were no holes in the trunks, where the trees could have been shot or
bored into. The homes had not undergone major construction that could
have affected the root systems.

When he visited the area, he noticed several other spots with dead
oaks, including several on the grounds of Seaford Elementary School.
That’s when he called Farrell.

“I asked Rob if he’s been seeing this,” Orban says. “And he told me
that when he was coming back from vacation, all along (Interstate) 64
he saw oaks going down.”

The Virginia Department of Forestry issued a news release earlier
this week addressing dozens of calls the office had received
about “hundreds of dead or dying oak trees” in eastern Virginia. In
the release, forest health specialist Chris Asaro said the most
plausible explanation was a combination of climatic extremes – a
drought several summers ago, followed by the heavy rains of Hurricane
Isabel and Tropical Storm Gaston, and finally this summer’s lengthy
heat wave.

“The trees were inundated with water, thereby causing their roots to
rot slowly over the last couple of years,” Asaro said in the
release. “With the onset of hot summer weather this June and July,
trees with rotted root systems were unable to obtain enough water and
simply wilted under the stress. Combine this with the advanced age of
most of the trees affected, and you have a formula for tree
mortality.”

He concluded “nothing could be done” to save the afflicted trees
because by the time the leaves began to wilt, they were already dead.

Orban and Farrell want to study the issue further. They want to find
out if there are other possible causes, such as an undiagnosed
disease or other external factors. They want to study why such
climatic conditions would be having this effect on oaks but not on
other trees.

“Hopefully when we combine my horticultural background with his
forestry knowledge, we can come up with some kind of speculation,”
Orban says. “I’d like it if we could solve some of this curiosity.”

Baker and other residents are also hopeful that today’s examinations
can turn up some answers – and some suggestions.

“I have a great big oak in the middle of my front yard, and I don’t
want to lose it,” Baker says. “Right now, it looks fine – but the
other ones looked fine, too. So that’s the biggest thing I want to
know: Tell me what to do to treat the other ones so I don’t lose
them.”