By CELESTE BAUMGARTNER
ATHENS, Ohio — It took about 40 years for chestnut blight to remove the American chestnut tree from the central and southern Appalachians. The chestnut was one of the tallest trees and made up about a quarter of trees in that range, said Brian McCarthy, president of the Ohio chapter of the American Chestnut Foundation (ACF).
That foundation hopes to restore American chestnuts for the benefit of the environment, wildlife and society and to create a template for restoring other trees.
Ben Finegan, president of the Indiana Chapter of ACF, who noted the record American chestnut tree in Tennessee was 17 feet across, put it this way: “I don’t know if it is spiritual or what, but when you see a tree like that, it is transformative. I want my kids to be able to experience that.”
The chestnut’s annual nut crop was a major source of food for humans and wildlife. Its decay-resistant wood was used for railroad ties, telephone poles and fence posts; most barns in the Appalachian region were clad with it, McCarthy said. The first warning signs of loss came in 1904 when rust-colored cankers developed on American chestnuts in the Bronx Zoo in New York.
“The blight came through the state of Ohio in the early 1930s and made it to the bottom of the Appalachians by the early 1940s,” he said. “The blight only affects mature canopy trees. When a tree dies back, it will actually re-sprout from around the root collar (the transition zone between the root and the stem).”
The American chestnut never went extinct, but now it only exists in the understory, in the sprouts, McCarthy explained. The trees may grow to 3-4 inches in diameter before they get re-infected with the blight, die back down to the stump and then re-sprout again.
Thirty years ago the ACF began a breeding program to backcross Chinese chestnut trees that were resistant to the blight with American chestnuts. They continued a program of multiple backcrosses over many subsequent generations to try to breed blight resistance into American chestnut.
“What they’ve got now is a third-generation backcross that has putatively blight resistance bred into it,” McCarthy said. “These trees are putatively 1/16th Chinese chestnut and 15/16th American chestnut. By continuing to breed the offspring back with pure American chestnut, you’re increasing the proportion of American chestnut in each generation.”
The trees are now in the third generation, he said. For the last two years the ACF has been planting them in test plantations to see if they resist the blight and if they have the same shape, form and life cycle as the American chestnut.
These chestnut trees will be blight-resistant, not blight-proof, McCarthy emphasized. They will be impacted by the fungus, maybe have some of the typical cankers, but should be able to live to old age, reproduce and be able to be put back into the landscape. It will take 3-5 years to know if the program has been successful.
The Indiana Chapter of ACF (there are 16 state chapters) has also been planting chestnut trees. Finegan is a landowner who moved to the country and had a barren cornfield. He started planting trees, stumbled on the American chestnut and the rest is personal history, he said.
“If you become a member of the ACF, in exchange for your support they give you a certain number of seeds,” he added. “There is a germplasm agreement you have to sign that you’re not going to sell the seeds. I have two of the restoration trees (the backcrossed trees) and probably 50 true American chestnuts.”
The Indiana chapter has an advanced breeding program, Finegan said. It is trying to generate lines of chestnut from mother trees native to the area that persisted despite the blight.
“They’d escape, get hit with a weaker strain, yet keep living for some reason,” he said. “The number of Indiana mother trees was like 28. Out of millions of trees, it got down to 28. The state champion tree, the biggest, best tree, is near Chicago. I believe that tree is like 30 or 40 years old.”
The chapter has also done restoration plantings in conjunction with the U.S. Forestry Service in the Hoosier National Forest. Those plantings, about an acre in size, were a variety of pure American, Chinese and the restoration chestnut.
“This tree is something we’ve lost to our country,” Finegan said. “We didn’t do it intentionally, but it happened. This is something where people – they can be everyday people, they can be scientists, they can be foresters, they can be landowners – they can get involved and make a difference.”
Hardwoods are Indiana’s third largest export, he said. Approximately 35,000 people are directly employed in the hardwood industry and another 80,000 in supporting roles. “When I’ve gone out and done talks or shows, when we did Earth Day, I didn’t stop talking for six hours. People don’t know what a chestnut is, they don’t realize the restoration process, but there is interest.”
For more information, visit www.acf.org