The American chestnut (Castenea dentata) was once the most dominant tree in eastern forests. In some cases, one in every four trees found in the east were chestnut trees. This straight, fast growing tree reached a very large size, approaching 150 feet tall and 5 to 10 feet in diameter. The majestic chestnut was prized for its timber which was strong, straight, and very rot resistant. At its prime, there were nearly four billion chestnut trees found in the eastern forests. All of that changed with the introduction of Chestnut Blight (Endothia parastitica,) a fungal disease that was first identified at the Bronx Zoo in 1904. This wind borne affliction quickly spread throughout the native chestnut range, and by 1940, most American chestnuts had been wiped out.
Today it is estimated that less than 100 of the four billion original chestnuts are still alive. In the case of diseased trees, although the upper portion of the tree died, in many cases, the root system remains alive. These root systems continue to send out sprouts that will grow for about 20 years until they become reinfected and die back to the ground. American chestnut sprouts are not uncommon in Frederick County, but finding a large healthy American chestnut tree is a very rare occurrence. Our native chinkapins and post oaks are also affected by the chestnut blight but it is not lethal to them.
The Chinese chestnut (Castenea mollissima) has a natural resistance to the chestnut blight and it is thought that the importation of this tree brought the blight over to our shores. Chinese chestnut is a medium sized tree with a large spreading crown. The Chinese chestnut is the “chestnut” tree that is most often planted in groves or in a landscape setting for their nuts. There are a number of active programs to re-establish American chestnuts, most of which are being coordinated by the American Chestnut Foundation. Most of these programs attempt to breed resistance into chestnuts. At present, there are a number of chestnut orchards and plantations located throughout Frederick County that are tended by volunteers. Another way chestnuts can become more resistant to the blight is to develop a natural immunity called hypovirulence. In some cases, this natural resistance occurs as a result of a virus attacking the blight.
Article by FCFCDB
Nature Note for 9/10/2017