Ghosts in the woods
By S. Heather Duncan
TELEGRAPH STAFF WRITER
Grant Blankenship, The Telegraph
Though the chestnut shares leaf shapes with other
more common trees, other characteristics like its flowers and a
distinctive spiny seed pod distinguish it.
PINE MOUNTAIN
- The phantom of a lost forest lives
on Pine Mountain.
It rises 45 feet in the air not a quarter mile from
President Franklin D. Roosevelt's favorite picnic spot - where he
might, once, have roasted chestnuts over an open fire.
The American chestnut tree is now so rare that when
Culloden resident Nathan Klaus found a mature specimen n FDR State Park, it excited scientists up and down the East
Coast.
American chestnuts, once a plentiful source of food
and fine timber throughout the Appalachian mountains, were all but
wiped out by the Asian chestnut blight by the time Roosevelt served
as president.
Until then, as much as half the mountain tree
canopy may have been chestnut trees, which grew up to 100 feet tall
with a life span as long as 300 years.
In the process, their role as a home and food
source for many animals was destroyed. "Ecologically, the chestnut
doesn't exist anymore," said Klaus, wildlife biologist with the
Georgia Department of Natural Resources. "These are sort of ghosts
there in the woods."
The Pine Mountain tree, now named after Klaus, is
even more usual: It's believed to be the southernmost mature,
naturally-occurring American chestnut to resist the blight. David
Keehn, breeding coordinator for the Georgia chapter of the American
Chestnut Foundation, guessed the tree could be anywhere from 25 to 50
years old.
The large tree is surrounded by other younger, but
still unusually long-surviving, chestnuts. While walking around the
area Friday, Klaus spotted even more.
This small stand is rare not only for its location
but its apparent ability to produce germinating seeds. The lonely
survivors usually can't pollinate themselves, Klaus said.
Although hundreds or possibly 1,000 mature American
chestnuts are believed to have survived the blight - an estimated two
or three per county in the tree's former range - "Trees large enough
to flower and produce nuts are very rare," Keehn said. "Especially to
find two of this size is spectacular."
Members of the Georgia Botanical Society on Friday
squinted upward as the sun spotted the tree's narrow, saw-edged
leaves. They were looking for the distant extensions at the tips of
the tallest branches that will become fingers of tiny flowers.
On the ground are last year's nut cases, which are
now brown and delicately spiky like a sea urchin.
"This is not normal," Klaus said. "Normal is
pathetic, stunted, and makes you just want to go home and cry. Either
this place is special or these trees are special."
The root system of trees killed by the blight
survives, sending up new shoots. But the usual results are visible a
little farther down the Pine Mountain trail: A clump of gray, dead
stems killed when they were only a few feet tall.
The Klaus tree will become a "mother" to
potentially thousands of other American chestnuts through a breeding
program of the American Chestnut Foundation. The foundation
pollinates surviving chestnuts that seem to have a strong natural
resistance to the blight, crossing them with other survivors, and
planting the resulting nuts at a test site. There, the strong
American chestnut strains are crossed with now-common Chinese
chestnuts, with the goal of breeding in the Chinese blight resistance
but keeping all other American characteristics.
After 23 years, in 2005 the experiment finally
yielded 118 nuts of what are expected to be highly blight-resistant
chestnuts that are 15/16ths American, Keehn said.
Adding new genetic material to the mix will make
the species more likely to survive, and Georgia specimens are key to
reviving the trees this far south. There are only five other Georgia
trees in the foundation's "mother tree" inventory, Keehn said.
Chestnut trees flower for only a few days, so
Georgia Botanical Society volunteers trekked in Friday with heavy
scaffolding to prepare for pollinating the flowers when the time
comes.
Groups besides the American Chestnut Foundation are
studying other methods of beating the virus. The American Chestnut
Cooperator's Foundation, based at Virginia Tech, is trying to create
a pure American, blight-resistant strain of chestnut.
At the University of Georgia's School of Forestry
and Natural Resources, professor Scott Merkle has been using
biotechnology for 16 years to study ways to clone resistant chestnuts
or transfer anti-fungal genes into tree embryos. His lab has
perfected the process and plans to start testing five or six
anti-fungal genes within the next three months, Merkle said.
Merkle can clone 100 chestnut seedlings from a
single embryo, and would like to eventually clone the chestnut
foundation's blight-resistant trees.
To contact writer S. Heather Duncan, call 744-4225
or e-mail hduncan@macontel.com.
*****
American versus Chinese chestnut trees
Chinese chestnut trees are now more common in North
America than the native species. Here are some key ways to tell the
difference between the two:
Leaves: American
chestnut leaves are thin and papery, long in relation to their width,
with long, prominent 'teeth' along the edge and a sharply tapered
base.
Chinese chestnut leaves are oval, with smaller teeth, a rounded base,
and a more waxy, thick feel.
Burs (the prickly case for the nut):
American burs are a dense mass of long, slender spines. Chinese burs
have a sparse mass of short, thick spines.
Nuts: American nuts
are relatively small, half an inch to an inch in diameter, with
pointed tips and hair over a large portion of the nut. Chinese
chestnuts are almost twice as large, with hair only on the rounded
tips.
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