Is the American Chestnut Tree Making a Comeback?

During the latter part of the 19^th and into the 20^th centuries, one of the most important, if not the most important tree to east coast United States residents, was the American Chestnut. The American Chestnut tree grows to an astounding height of 150 feet and a girth of 10 feet. It was used, especially in Appalachia, to build homes, and everything from cradles to caskets. The nuts drew abundant wildlife, providing food for livestock and humans, as well.

Demise of the American Chestnut

Tragically, beginning about the year 1904 (starting within the Bronx Zoo), some four billion American Chestnut trees (Castanea dentata) were wiped out in less than fifty years by blight¹ brought into the country on Chinese Chestnut trees. Once the blight began, rapid, panic cutting of American Chestnut trees began to save the wood that remained. Sadly, this assured the blight's devastation, since some of the harvested trees might have proven blight resistant.

Hope for Castanea Dentata

Not every American Chestnut tree was destroyed. Some isolated trees remained, including some trees in western parts which never were exposed to blight. In the east, there are still shrub-sized remnants of the magnificent trees-as the author can attest-there existing some on his former property. The trees suffering the blight die back, but shoots reappear and may reach a height of 10 feet or more, before suffering the same fate. Some may even develop a few nuts.

Initial Efforts Fail

Although reforestation from unaffected American Chestnut stock would be ideal, realistically, research was needed to consider alternatives. The most promising derivative of this research was to breed in the immunity of the Chinese Chestnut (Japanese Chestnut trees have also been discovered to possess immunity). Some of the remaining unaffected American Chestnut trees (of which there are over 500) are thus crossed with Chinese Chestnut. Unfortunately, the initial cross bears many characteristics of the Chinese Chestnut tree, which doesn't possess the stately characteristics of Castanea Dentata. More insights were needed.

The American Chestnut Foundation Steps Up to the Plate

In the late 1970's, researchers began instituting the suggestions of Dr. Charles Burnham, founder of The American Chestnut Foundation (TACF). Researchers began back breeding to increase the percentage of the American variety. The procedure is actually more complex than it sounds. For those more technically inclined among us, The American Chestnut Foundation provides an in-depth PDF file describing their methodology.

Is It Working?

Although Dr. Burnham's suggestions appear to be working well and they may be accepted as the final solution, challenges remain. The new trees have proven susceptible, (says Science Daily²) to a soil fungus, Phytophthora cinnamomi, or root rot. In addition, some may view the hybrid trees, though to all outward appearances it is the same as American Chestnut, as an unacceptable competitor that could replace the true American Chestnut. In that case, further research will be necessary to suggest an alternative.

¹ The blight was due to an Asian bark fungus, Cryphonectria parasitica.

² Science Daily - "Challenges Remain In Reintroducing American Chestnut," August 2007.

References and Resources:

The American Chestnut Foundation

Connecticut Agricultural Experiment Station - "Revitalization of the Majestic Chestnut: Chestnut Blight Disease," by Sandra L. Anagnostakis.