GARDEN TALK
The Revival of the
Forest Monarch
As the United States watches our
landscape change and trees going
dormant for winter, one species
of tree that used to dominate our
forests is missing: the American
chestnut.
Before the early 1900s, The
American chestnut tree, Casta-
nea dentata, was the undisputed
monarch of eastern U.S. temperate
deciduous forests. Forest ecolo-
gists estimate that approximately
one in every four hardwood trees
in North America’s eastern forests
was an American chestnut. Four
billion chestnut trees reigned over
30 million acres from northern
Florida to Maine, with the heart
of their empire being the ancient,
Appalachian Mountains. There were
so many chestnut trees that every
spring when the trees flowered with
white blossoms, from a distance,
the hills appeared to be covered
with a blanket of snow.
American chestnuts were argu-
ably the most important tree in
U.S. eastern forests with very few
rivals. They grew very fast and very
big, reaching heights over 100 feet
tall, diameters of 10 feet wide and
exceeding 300 years of age. Wildlife
and people enjoyed the sweet nutri-
tious nuts that were full of protein,
carbohydrates and fat while being
high in vitamins and fiber. One
large, mature tree could produce as
many as 6,000 late-blossoming nuts
that were generally unaffected by
late frosts.
People constructed their lives
around this tree that helped to build
a nation during the eighteenth and
nineteenth centuries. American
chestnut wood was used to build
everything
from cabins,
barns, and
fences to fine
furniture and
pianos. It was
renowned for
its beautiful,
blonde color
and bold,
straight grain
that was easy to work with and
extremely rot-resistant.
However, in the late 1800s, an in-
visible enemy arrived on the shores
of America that would ultimately
devastate the dynasty of this forest
monarch. In 1876, in New York
City, Japanese chestnut trees were
imported into the U.S. for plant-
ing in local gardens. These trees
carried an exotic invasive species, a
pathogenic fungus called Crypho-
nectria parasitica, or more com-
monly known — chestnut blight.
Asian chestnut tree species, like the
22 • Louisville Zoo Trunkline • Winter 2016
American chestnut tree bark
American chestnut tree at the Zoo
Japanese and Chinese chestnut, had
long ago evolved resistance to this
fungus, but the American chestnut,
which had never encountered this
pathogen before, was extremely
susceptible to this fungal disease.
Within 70 years, the effects of
chestnut blight had rippled like a
shockwave through the eastern
forests of the U.S. and obliterated
nearly 4 billion trees. Only a hand-
ful of mature trees resistant to the
blight could be found. Many of the
trees killed off by the blight re-
mained alive below ground, only to
American chestnut tree leaf