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American Chestnut
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There was a time when the American Chestnut (Castanea dentata) was the hallmark
of forestation in the eastern United States. Once known as the Eastern
Redwood, 100 foot trees with six to eight foot diameter trunks were common
and 150 foot trees with ten foot diameter trunks were not unheard of.
The trees ranged form Maine to north Georgia and from the Ohio valley to the
Carolinas. The trees were so abundant in parts of the Appalachians
that in spring when the trees would bloom, the mountains would appear snow
capped.
The fruit, the chestnut itself, was a cash crop for many as well as a food
staple for both humans and wild life. The bark was used for it's
tannin in the leather industry. Extracts from the leaves were mixed
with honey to make a cough syrup and other home remedies. The wood was
stable; it worked well, didn't warp and was very resistant to both, rot and
most insect infestation. Accordingly, it was used for everything from
split rail fences and telephone poles to fine furniture and everything in
between. It was known as the "craddle to grave" tree, meaning a limb
was big enough to build your cradle, the nuts could feed you as grew up, the
tree had enough lumber to build your house, and there would be enough lumber
left over to build your casket when you died.
Sometime between 1890 and 1903, the fungus Cryphonectria parasitica
(formerly Endothia parasitica), commonly known as the chestnut blight, was
brought into the United States, presumably on either chestnut trees or
lumber imported from the orient. It was first noticed in 1904 by
Herman W. Merkel, a forester at the Bronx Zoo. The fungus enters
a tree through cracks in the bark and rapidly makes a canker which girdles
it destroying the trees cambium layer. Everything above the canker is
killed. The fungus is spread by all the normal mechanisms: wind, rain,
birds, etc. The American chestnut had no defense from the fungus and
by the late 1930s, most of trees within the natural range were either dying
or already dead. Although the fungus kills the trees, it doesn't
extend to the tree's root system and saplings from sprouted roots can still
be found. The saplings usually succumb to the fungus before they can
become fruit bearing.
Another problem for the American chestnuts are chestnut weevils. The
large chestnut weevil (Curculio caryatrypes) and it's cousin, the small
chestnut weevil (C. sayii), are North American natives. These two
parasites are what give chestnut wood it's "wormy" appearance. Female
adults lay their eggs in a hole they've chewed in the fruit. After the
larvae hatch, the feed on the (now fallen) nut for six to ten weeks.
The larvae then spend the winter in the surrounding soil. They pupate
in late spring or early summer and the adults come out in mid summer (around
August) to start the process all over again.
To make matters worse, a new pest is now threatening our chestnut trees.
The Oriental Chestnut Gall Wasp
(Dryocosmus kuriphilus) has been found on American chestnut trees growing
along the Appalachian Trail at the southern end of it's range. On
June 19, 1993, galls were found on native American chestnut trees in the
Chattahoochee National Forest in northern Georgia. It is believed that
this parasite was brought into Georgia in 1974 from Asia, on cuttings that
did not go through plant quarantine.
Through research to combat the galls, cross breeding American chestnut trees
with trees that are resistant to the fungus and natural selection, wonderful
groups like the American Chestnut Foundation
and the American Chestnut Cooperators' Foundation
are trying to reintroduce this magnificent tree to the American landscape.
If you want to learn more, start with the chestnut links at your left.
If you want to DO more, plant one... or at least don't chop one down!
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