It’s been quite a while since vendors offered American chestnuts on urban streets. The variety that once filled the air with its festive aroma is nearly extinct. This beloved chestnut is largely absent from our lives today, but the memories of its significance continue to inspire researchers committed to its revival. Many recall a time when the wood from this tree richly adorned homes and schools, or share nostalgic images of vendors in Baltimore serving warm, charcoal-cooked chestnuts.

Sara Fern Fitzsimmons, the chief conservation officer for The American Chestnut Foundation, emphasizes the deep connection people feel toward this tree. She reflects on its historical importance, saying, “You can feel that connection to a place, and that connection to utility, and the connection to the importance that this tree played in virtually every aspect of the lives of people.” However, she acknowledges that restoring this once-thriving species may take longer than enthusiasts had anticipated. Researchers are facing obstacles in their efforts to breed or genetically alter a chestnut that can resist the blight that has devastated the species since the early 1900s. If they succeed in developing a suitable variety, the next challenge will be to ensure its vitality in forests stressed by climate change, urban expansion, and global influences.

Historically, American chestnuts thrived in forests stretching from Georgia to New England. Today, much of what remains exists as an underground network of roots sending up shoots. While they can survive for a while, the fatal fungal blight takes over as the trees mature. In contrast, East Asian varieties bring the blight and are resistant to it; these species produce the bulk of edible chestnuts available during autumn and winter. Regardless, American chestnuts are invaluable as timber, cherished for cultural significance, and essential for maintaining ecological balance in forests by offering food and shelter for wildlife and people alike. Amy Brunner, an associate professor at Virginia Tech, remarks, “It was really a pretty significant species to lose… The more diversity you lose, the less resilient that forest ecosystem is.”

The American Chestnut Foundation has dedicated decades to breeding a hybrid that possesses predominantly American genetics while incorporating the effective blight resistance of Chinese varieties. Fitzsimmons observes the challenges inherent in this endeavor; achieving blight resistance involves multiple genes that are difficult to separate from those that define the Chinese chestnut. To expedite progress, some researchers are exploring genetic modification as a means to enhance the American chestnut’s immunity. Unfortunately, a recent mix-up with genetically modified varieties at the State University of New York has delayed regulatory approval that they had hoped to achieve this year.

Linda McGuigan, a research support specialist at the university, expresses disappointment over the delay. “It kind of stinks that it happened because now it’s taking a little bit longer than we had hoped,” she said. Despite these setbacks, scientists are actively pursuing various pathways to success. Brunner points out that both breeding and genetic modification are essential. Breeding fosters the necessary genetic diversity for adaptation, but genetic engineering may be required to ensure adequate blight resistance for the trees.

In the meantime, researchers are also addressing another significant challenge: determining suitable locations for planting the revitalized chestnuts. Given the dynamic conditions brought about by climate change, scientists must strategically decide where to plant these trees to ensure their survival. A research team at Virginia Tech has published findings that explore this question by examining 32 climate variables. They compare these aspects to projected future climate scenarios and calculate how far regionally sourced American chestnuts may need to migrate to thrive in changing conditions. This research could eventually aid in locating the most viable areas for planting, keeping the trees close to their historical habitats.

Fitzsimmons describes this research initiative as “revolutionary,” highlighting its potential impact on the future of the American chestnut. The work will provide vital information for understanding where to gather genetic material from the remaining immature chestnuts across North America. Tom Kimmerer, a forest scientist formerly of the University of Kentucky, lauds the importance of this research, calling it “robust and well supported,” noting that it is critical for the success of reviving the chestnut tree.

Stacy Clark, a research forester with the U.S. Forest Service, agrees the findings are promising but emphasizes the need for practical validation through field experiments. “I think with advancements in genetics, they can probably get pretty fast data off of those field trials. But still, all of that takes time and effort,” she said.

Forest scientists recognize that their work may not yield results within their own lifetimes. This reality became even more poignant after the recent passing of pioneering researchers Bill Powell and Chuck Maynard. McGuigan, who supported their work for years, remarked, “The project moves on, lives on. And we honor their memory. I want to do something good for the future, for my children.”