Saturday, July 11, 2009
"For there is hope for a tree, if it is cut down, that it will sprout again, and that its tender shoots will not cease.” Job 14:7
If you are a member of my generation, you probably have never seen an American Chestnut tree, or realize how big they can become. When I hear the word chestnut, Chinese chestnut trees come to mind. As children, we collected fallen nuts from our neighbors' yards. Those trees were never bigger than an apple tree, so it surprised me to learn that the majestic American Chestnut tree often soared to heights of over 100 feet.
In the picture to the right, there are two men standing between three American Chestnuts, dwarfed by the base of these trees. American Chestnuts grew quite rapidly, leaving other woodland trees in their shadows to compete for food resources. An estimated 3.5 billion American chestnut trees...gobs and gobs of them, formed thick dense canopies. As recently as 1910, chestnuts ranged (see map here) throughout the eastern forests from Maine to Georgia!
Then the blight was transported to our country on Chinese Chestnut treestock. Between 1927 and 1937, the most important tree in our Eastern forest was reduced to insignificance as American Chestnut giants became leafless. However, the root systems beneath the stumps of the dead tees were somehow able to survive the blight.
David W. Wooddell, research editor with National Geographic, referred to the mighty chestnut as the "Redwood of the East":
"The American chestnut was not just the dominant tree in many forests but one of the most prolific nut trees in the eastern region of the United States. Its annual nut crop was a dietary staple for large populations of white-tailed deer, bear, squirrels, and wild turkeys. The nuts were so vital to these wild creatures that after the chestnut’s demise, the animal populations dependant on it as a food source crashed as well. Today they have barely recovered from the loss of their chestnut-forest habitat in the Appalachian Mountain regions.
Chestnut trees were also useful to people. The nuts, harvested and sold to farmers for animal feed, were important to the rural economy until the 1920s and 1930s. The tannin found in the nuts and wood was used in the leather-tanning industry and as pigment in wood stains for the furniture industry. Chestnut lumber was rot-resistant and was widely used for buildings and fences. Many 18th- and 19th-century log cabins were made of old-growth chestnut logs and still stand today as a testament to the durability of the wood. The chestnut was so useful that some people called it the redwood of the East."
I find it fascinating that a few trees in Virginia and North Carolina seemed to survive that blight to this day. Will Cook, with the biology department of Duke University in North Carolina, has photographed trees in both states and posted them online here. A healthy 51' tall tree (13.5" circumference) is noted from Carroll County, Virginia. Besides its large size, this individual tree is quite unusual in that it is not a stump sprout.
Again and again, tender shoots rise up from the roots of these dead stumps. Once the sprouts become a few years old though, they usually become infected with the blight and die back unless grafted onto blight resistant Chinese chestnut trees. How interesting that the tree that caused the demise of the grand American Chestnut also provides the genetics for the breeding program that will help to save it!
The grafted trees are able to provide American Chestnut pollen to fertilize Chinese chestnuts. Offspring are backcrossed again with American Chestnut pollen. Attempts to hybridize remaining American chestnut trees with blight-resistant Chinese chestnuts have resulted in a species that is about 15/16ths American chestnut with the protection found in the Chinese species.
The goal of the American Chestnut Foundation (TACF) is to restore the American chestnut tree to its native range within the woodlands of the eastern United States. The ACF havested the first blight-resistant nuts in 2005, and will begin reforestation trials with blight-resistant American-type trees. Perhaps in my lifetime, most of my generation will be fortunate enough to see an American Chestnut tree towering in their horizon.
Surviving trees generate great excitement, as they provide valuable genetic material and hopefully a key to disease resistance. If you know of any, please contact the Virginia Chapter of the American Chestnut Foundation. They provide a printable mail-in form to submit with a leaf and twig sample. An analysis of the characteristics and microscopics will be completed by a TACF identification expert and the results will be sent to the submitter.