watercolor by katherine robinson

Bringing Back the American Chestnut

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Please welcome guest author Adrian Johansen. She currently resides in the Pacific Northwest, but covers a variety of topics related to sustainability, diversity and development. You can follow her on Twitter at @adrianjohanse18.

Just as the Appalachian region has a rich history, so does its environment. Its rolling hills and scenic greenery have shaped not only the culture of those who live here, but America itself. 

Unfortunately, over the years, changes to the landscape — both environmental changes and human interference — have resulted in some of the precious species in the area diminishing or becoming extinct. One such species is the American chestnut.

closeup of ripe chestnuts

What is the American Chestnut?

The American chestnut (Castanea dentata) is a deciduous tree of significant size that is native to the Appalachian region. The most recognizable feature of this species of tree is the edible nut it produces inside a burred fruit. 

Before the transition to the 20th century, the American chestnut was one of the most important and dominant trees in the region, spreading over 200 million acres. It was considered the finest and most prolific tree across the globe. 

Due to its size, strength, resistance to rot, long lifespan, and rapid growth, the American chestnut was often used for building purposes, such as for log cabins, flooring, poles, posts, and railroad ties. The edible nut that grew on the tree was also essential to the rural economy. 

Livestock was often fed the chestnuts to fatten them up for market, and during Thanksgiving and Christmas, chestnuts were a special treat, becoming a famous holiday tradition. “Chestnuts roasting on an open fire,” went the line in the 1945 song “The Christmas Song (Merry Christmas to You,” by Robert Wells and Mel Tormé. 

fog in a mountain valley

What Happened to the American Chestnut?

At the turn of the century, things changed when the American chestnut was devastated by blight. It began with some well-meaning growers who brought over some Chinese chestnut trees from East Asia to crossbreed with the American chestnut. 

Unfortunately, the imported trees brought with them a deadly fungus — Cryphonectria parasitica — that began to infect the American trees. The blight swept through the Appalachian forest at a rate of 50 miles a year, leaving the species as nothing more than an early-succession-stage shrub. 

Now, the American chestnut is hard to come by. Almost no chestnut lumber has been sold in the states for several decades. And the majority of the 20-million pound annual nut crop now comes from imported nuts and newer species.

Current Issues Affecting the Appalachian Environment Today

While Appalachian flora and fauna still thrives, more issues could result in the extinction of other species, and that could make it difficult to restore the American chestnut. The chestnut blight, for example, was not the only invasive species that altered Appalachian ecosystems. 

The hemlock wooly adelgid and the balsam wooly adelgid — pests introduced from Asia and Europe — have destroyed hemlock and pine trees throughout Eastern forests. And the spotted lanternfly, also from Asia, is destructive to a variety of plant species and is rapidly spreading throughout the Appalachian region. 

These invasive pests have been able to survive because they have no natural predators, and because most pests have been able to expand and alter their migration patterns due to climate change. Climate change itself is also an issue as rising temperatures continue to result in devastating wildfires that wipe out significant portions of U.S. forests. Don’t assume this is only a western U.S. issue. True, Appalachia doesn’t have as many fires as out west, but droughts may be the new normal in Appalachia, causing more wildfires than previously.

lab researcher holds a chestnut leaf

Restoring the American Chestnut

Despite the large-scale decimation, the American chestnut has not gone entirely extinct. And scientists and restoration specialists have been trying to restore it to its former glory. There are still some American chestnuts growing in Appalachian forests today, but they don’t last long before blight gets to them.

This has been an ongoing issue for decades. Many have tried to repopulate the species, getting excited when roots and sprouts begin to grow, but blight inevitably takes hold and wipes them out. It’s a never-ending cycle. 

To combat this issue, researchers have been trying to find a way to alter the genetics of the American chestnut in an attempt to make it resistant to blight. William Powell, director of the American Chestnut Research and Restoration Project at the University of New York in Syracuse, has been working for 35 years to restore the chestnut tree using genetic engineering.

Powell and his colleagues discovered a gene in wheat plants that can enhance resistance to the blight-causing fungus. The gene produces an enzyme that detoxifies the fungus acid that breaks down the trees, giving the species a natural weapon to fight against blight. 

Researchers at the State University of New York College of Environmental Science and Forestry (SUNY ESF) have also discovered a way to alter the genetics of the chestnut tree to make it blight-resistant.  Their method of gene editing to save the American chestnut involves the use of pollen that will carry the DNA to fight off the fungus. 

However, their project, as well as others, are struggling to gain approval. They not only have to go through federal agencies but must also face the concerns of American chestnut enthusiasts and historians who are worried about what it means to alter the genome of this beloved heritage tree. 

The American Chestnut Foundation, in partnership with the USDA Forest Service, is also close to restoring the tree using bioengineering. However, they likewise have concerns. Primarily, what conditions are necessary to bring back the American chestnut and ensure it can fully grow and repopulate on a large scale? 

While efforts are underway to develop management protocols for foresters to reintroduce the species, climate change remains a threat. Climate change can result in several things that can wipe out the chestnut trees once again, such as pests, other diseases, and wildfires. 

But repopulating the Appalachian region with genetically modified trees that are much stronger can also help combat the effects of climate change. Not just the American chestnut, but several tree species, could be altered in similar ways to help restore forests that have been decimated by climate change and disease. 
And this is not only beneficial to the environment and American chestnut aficionados that want to see the species restored. It is also a benefit to public health. Humans’ health naturally benefits when immersed in nature, so more chestnut trees essentially mean parks and more greenery for people to enjoy.

chestnuts laid on stack of fall colored chestnut leaves

Final Thoughts

So, perhaps the eastern forests of the U.S. will once again be graced with the magnificence of the American chestnut. It may yet take some time to get approval and to ensure the trees have the right conditions to grow, but repopulating the species is likely not that far off. Perhaps we will even see the restoration of many other species using genetic engineering to make them resistant to blight and other effects of climate change. 

6 comments

  1. I have land in west Tennessee I would love to place a study group or by for my own pleasure

  2. In south Mississippi, my Chinese chestnut does great. Hope the American chestnut will make a comeback but it’s been many years ……..

  3. Am growing American chestnuts but will eat least 3 years before they flower and can be pollinated by transgenic pollen. I hope to see it happen! Your photos of the nuts do not look like American chestnuts, Americans are smaller and maximum of 3 per bur.

  4. In the early 90’s I purchased 12 America chestnut trees that were supposed to be blight resistant . Sadly all but one died after their 5th year. The last made it to 10 years but died. It still has sprouts but they die off. Would love to plant some that would survive.

  5. I grew up in a small town call Pratt, MN. We had a American Chestnut tree in our yard. Would love to grew some of them.

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