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Fort Mountain
— In a deeply shaded hard wood cove in Fort Mountain State Park, Don
Davis
imagines what it would have looked like a century ago — just before
the chestnut blight hit.
“This probably was
a great place for chest nuts,” he said. “The trees would have been
huge, rivaling California’s redwoods.”
He believes it can be that way again.
One hundred years after
the chestnut blight first appeared at the Bronx Zoo in New York, and
decades after trying to develop a blight- resistant tree, researchers
are now confident that the once majestic chestnut can return to its
former glory.
“Some feel that we’ve already turned the corner,
and it’s only a matter of time before the chestnut is again the grand
tree of the forest,” said Davis, a Dalton State College sociology
professor and
a chestnut historian.
The American Chestnut Foundation, whose goal is to
restore the tree to its native range in the eastern United States,
expects to have blight resistant trees ready for mass planting by the
end of this decade.
Looking ahead to that time, Davis and others are trying to
establish a chapter of the organization in Georgia to aid them in
re-establishing the tree in the state.
“It will create jobs for the timber industry and develop a new
source of food for man and animals,” he said.
Fast-growing American chestnuts once made up more than
a quarter of the trees in eastern woodlands. They soared to more than
a hundred feet tall and produced copious quantities of savory nuts
that nourished numerous birds and animals. Their stout, straight
trunks yielded unusually strong, root timber ideal for utility poles
and fence posts.
“They were the greatest trees in the forest,” Davis said.
Then, disaster struck: A deadly fungus from Asia, Cry
phonectria parasitica, was discovered on chestnuts in New York in the
summer of 1904. The disease was quickly spread southward by wind,
rain and birds at an astounding rate of 50 miles per year.
By the mid-1930s, the fungus had reached north Georgia, and by
1940 there was scarcely a tree in the entire state that was not
infected with the disease.
Nationwide, more than 3 billion trees were felled by the
so-called chestnut blight. The fungus grows in and under the tree
bark, creating large visible sores called cankers that prevent the
flow of sap. The cankers eventually encircle the tree, effectively
strangling it.
The roots of many trees, however, have survived. They still send up
saplings that grow up to 25 feet before they, too, succumb to the
blight.
“This one will be dead
soon,” said Davis, pointing to an orange tint on the trunk of a
20-foot chestnut, the first signs of the blight. But before
that happens, he said, it might bloom this summer and produce pollen.
That
possibility drew him recently to the state park in Murray County, 90
miles north of Atlanta, where scores of chestnut saplings still
sprout from old stumps.
Davis wanted to identify chestnuts from which researchers possibly
could collect pollen this summer.
Collecting the material from wild American chestnuts is part
of the strategy for ultimately restoring the trees to the forest
Pollen from various trees will help create a variety of chestnuts
that will enhance chances of survival in the wild, Davis said.
Slow process
Researchers are using both traditional plant-breeding techniques and
genetic engineering methods to develop blight-resistant trees.
The plan is to end up with an exact copy
— or nearly an exact copy — of the American chestnut of old.
It’s a painstakingly slow process.
In one approach, plant geneticists at the University of
Georgia and other institutions are working to create a blight- free
tree by inserting fungal resistance genes from other species directly
into the chestnut tree.
In another technique, researchers hope to encourage a virus —
first discovered in European chestnuts — that attacks the chestnut
blight fungus itself. Researchers at West Virginia University
reported last fall that they had good results introducing the virus
to cankers in individual trees, but had a problem in getting it to
spread through an orchard of chestnuts.
But in what experts say is the most promising approach,
researchers at the American Chestnut Foundation’s research center in
Virginia have selectively combined American chestnut stocks with
blight-resistant Chinese varieties. The crosses have yielded
blight-resistant hybrids, but they are much shorter — growing only to
40-50 feet — than the pure American chestnuts, which soared as high
as 100 feet and had trunks six feet or more in diameter.
In the forest, the diminutive, slower-growing hybrids can’t
compete for sunlight with maples, beeches, ashes, oaks and pines.
However, the American-Chinese hybrids are bred back top American
chestnuts in al process called “backcrossing.” In essence, the
researchers are trying to rid the tree of as many Chinese genes as
possible except for one — the gene that confers resistance to the
blight.
After several such back-
crossings during the past two decades, researchers now have trees
that are fifteen sixteenths American chestnut— with the potential for
blight-resistance and growing as tall as the old natives.
“Except- for a few minor characteristics, they essentially are
American chest nuts,” Davis said.
A final step is to breed the trees with each other to pro duce
trees that have a chance of inheriting blight-resistant genes from
both parents. They will serve as the mother trees to produce nuts —
expected about 2007 — for reforestation.
Only until the nuts are planted and the trees from them grow
for 30-40 years will researchers know beyond a doubt that they have
produced a blight-resistant tree with all of the characteristics of
the original American chestnut.
But researchers and others already are confident of success,
and they are now proceeding with plans to restore the tree to the
American landscape over the next several decades.
“Our confidence level is very high that we will once again
have soaring chestnuts in our forests,” said Phil Pritchard of the
American Chest nut Foundation’s regional office in Asheville.
Seeking support
A group of Georgians
wants to make sure that the state is not left out in the revival. To
that end, Jerry and Dianne Smith of Dalton are among a core of
chestnut enthusiasts working with Davis to establish a chapter of the
American Chestnut Foundation in Georgia. Such a chapter, Jerry Smith
said, would allow the state to tap into the national group’s
organizational strength and pave the way for obtaining
blight-resistant chestnuts for Georgia.
“We want the whole state of Georgia involved in this project,”
he says. “The whole state will benefit if we can bring the chestnut
back.”
On The Web: For more information about
this topic: call 706-259- 9010 or visit the American Chestnut
Foundation Web site www.acf.org or
the Georgia Chapter site at
www.gatacf.org.
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