Organism of the Day
|August 01, 2012||Yellow Buckeye / Aesculus flava|
|July 27, 2012||Eastern Hay-Scented vs. New York Fern /|
|July 25, 2012||Leaf-footed Bug Nymph / Acanthocephala terminalis|
|July 23, 2012||Timber Rattlesnake / Crotalus horridus|
|July 20, 2012||Smooth Chanterelle / Cantharellus lateritius|
|July 19, 2012||Black Rat Snake / Pantherophis obsoletus|
American Chestnut, Castanea dentata
July 15, 2011
The American Chestnut was once the giant of the Appalachian forest canopy. Their native range encompasses most of the Appalachian mountain range, as far north as southern Maine and south as far as Alabama. These trees once reached the height of 30.5 m (100 ft), and diameters as great as 20 ft were not uncommon. They grew especially robustly in prime habitats such as mountainous and hilly regions. Their greatest size was reached in the Southern Appalachian Mountains.
The American Chestnut is easy to identify. Its alternate, simple leaves are 13-20 cm long (5-8 in) and are characteristically deeply toothed (thus the name dentata). The leaves are darker green above and paler below; both sides are hairless. The leaves grow on twigs and stems that are chestnut- to orange-brown and similarly hairless. These monoecious trees produce small, pale-green-to-white male flowers tightly packed along catkins 15-20 cm (6-8 in) long. The female flowers occur singly in June-July at the base of the catkins. In the fall, the fruits ripen as spiny husks 5-6 cm in diameter, which enclose 2-3 shiny, brown chestnut nuts. These nuts are primarily round, but are often flattened on several sides. The nuts can be 1.3-5 cm in diameter.
These nuts used to be highly desired by squirrels, chipmunks, deer, and people. Indeed, many Appalachian families gathered chestnuts by the bushel to sell for extra money. Tannins produced by the chestnut trees once made up half of the vegetable tannins used by the American leather industry. Furthermore, chestnut wood was high-quality and durable. The importance of the Chestnut tree to the ecosystem was also great as a dominant and pervasive canopy tree. It was once said that a squirrel could travel from Georgia to Maine by jumping from Chestnut tree to Chestnut tree—without ever touching the ground. (Above, male flowers or catkins of the Chestnut tree)
In 1904, a fungus known as Endothia parasitica was discovered in Chestnut trees on the grounds of the New York Zoological Garden. It is believed that a shipment of Asian Chestnut trees, imported to North America as nursery stock, was carrying the fungus that would soon become known as the Chestnut Blight. The blight spread slowly and deliberately throughout the range of the American Chestnut from its original place of discovery in New York. By the 1960s, most American Chestnut trees in the Eastern U.S. were completely destroyed. (Below, Endothia parasitica on the bark of a chestnut tree)
The Chestnut Blight attacks Chestnut trees through cracks and wounds in their bark. From there, it spreads to the inner portion of the tree and encircles the stem, killing all growth above the point of infection. The leaves die first, followed gradually by the stems and trunk. This process can two to ten years, and leaves behind a dead, but erect, Chestnut tree. However, the rootstock survives. Chestnuts are present in our forests today, not as the giants of old, but as the stump-sprouts of those trees. They are continuously attacked by the blight, and rarely grow large enough to reproduce.
Following unsuccessful attempts to combat the fungus, the people of the Appalachians were left with a large amount of high-quality lumber. Stands of dead Chestnut that were left standing became infested with small borers, which drilled holes in the wood. When the wood was later harvested for lumber, the resulting timber was called “wormy chestnut.”
Mountain Lake was a prime Chestnut area. When the station was constructed in the 1920s and 30s, wormy chestnut was used for the interior of several cabins, including Clayton and Reed. Stump-sprouts can be found throughout the forest understory and continue to play an important, but different, role in the forest ecosystem. This specimen was collected near Wilbur Lab.
Article by Hazel Galloway
- Sources: www.appalachianwoods.com/appalachianwoods/history_of_the_american_chestnut.htm