This article was published in the Elsberry Democrat.
While I was hiking in Kentucky recently, I saw the remnants of a giant that wouldn’t die. On the side of the trail were numerous young American chestnut trees, Castanea dentata. They were sprouts from the rootstock of trees that dominated the eastern half of the United States until the early 1900s. And dominated is not too strong a word. One in four trees in the Appalachian Mountains was an American chestnut. The trees grew from Maine to the Mississippi river, and it was said that a squirrel could jump from chestnut tree to chestnut tree from Maine to Georgia without ever touching the ground.
Reaching heights of up to one hundred feet, the American chestnut was a colossus in both its inherent beauty and its usefulness to humans and wildlife. A tall, fast-growing timber tree, the wood was light and strong, with straight grain, and was highly rot-resistant. It was sought after for a wide variety of uses, including the bottom log of log cabins, railroad ties, fence posts, shingles, and fine furniture. Mature trees produced consistently huge crops of nuts that fed wildlife, livestock, and humans. American chestnuts supported huge populations of squirrels and fattened pre bears for their winter hibernation. Farmers fattened their hogs and cattle on the nuts prior to slaughter. Innumerable boxcars of the nuts were shipped to big cities for sale during the holiday season (“Chestnuts roasting on an open fire”). High in protein, the nuts added valuable nutrition to the diet of money-poor Appalachia, and were reliably bartered at local stores for supplies. Chestnuts from the European, Chinese, and Japanese species are used today in gluten-free diets and as a primary ingredient in some beers.
In 1904, a disease was discovered in the American chestnut trees in the Bronx Zoo. Several Japanese chestnut trees had been planted in the zoo, and it is believed that they had a fungus, Cryphonectria parasitica, when they were imported. Dispersed by wind, the fungus spread quickly, killing every tree it infected. The American chestnut had no resistance to a disease that the Japanese and Chinese chestnuts had evolved with for millennia. Salvage logging operations tried to stop the spread of the blight, without success. Within forty years, nearly all of the American chestnuts were huge, hulking skeletons. The tannins in the wood preserved them for years afterwards, enabling harvesting of the trees for many years after their death. More than 70 years after the death of the chestnuts, I saw the stump of one of these trees by one of the trailheads in Kentucky.
I saw young American chestnut trees growing by the side of the hiking trails in Kentucky. How is that possible? Although the chestnut blight spread quickly, it did not kill the roots of the trees. The root systems continue to send up sprouts, which produce enough energy to sustain the roots before the bark splits and allows the fungus to kill the young trees. These young trees die before they are able to reproduce, making it impossible for the American chestnut to evolve resistance to the disease on their own. Seeing these young trees, some nearly twenty feet high and on the cusp of being mature enough to produce nuts, made me both sad for what had happened and hopeful for the future.
There are numerous individuals and organizations working to bring back the American chestnut. As Americans settled west, they took chestnuts with them, and some trees planted as nuts outside the current range of the disease have escaped the blight. These trees and their offspring are being tested for resistance, and used for crossing with Chinese chestnuts. The Chinese trees are naturally resistant but aren’t as straight or tall as American chestnuts and their nuts are not as sweet. Eventually it is hoped to have a nearly 100% American chestnut with only enough Chinese genes in the trees to provide resistance to blight.
Another approach is genetic engineering. By inserting genes that provide blight resistance, the trees could reach maturity and reproduce. However, it will take years to confirm whether the resistance would be inherited by the offspring.
All of these avenues require an enormous amount of work and a great deal of time. It will likely be at least a century before we see American chestnuts as a thriving part of our ecosystem, and Chestnut Streets once again have their American namesake growing on them.
Additional Resources:
- Genetic engineering of chestnuts you tube
- American Chestnut Foundation
- American Chestnut Cooperator’s Foundation
- Freinkel, S. (2007) American Chestnut: The Life, Death, and Rebirth of a Perfect Tree. Berkeley, California: University of California Press.
- Free song by Dolly Parton (they want your name and e-mail address to get the download)