‘Tis the period for roasting chestnuts. But in the US, native ones are almost gone

It’s been a very long period since vendors sold the American chestnut on city sidewalks. It’s no longer the variety whose smell some people associate with Christmastime as it wafts from street carts. Because it’s virtually extinct.

But memories of the American chestnut’s legacy keep resurfacing for the researchers who desire to bring it back. They describe its wood that paneled the homes and schoolrooms of their grandparents, or the photographs of men on the street corners of ancient Baltimore, with warm bags of nuts cooked on charcoal.

“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 facet of the lives of people,” said Sara Fern Fitzsimmons, chief conservation officer with The American Chestnut Foundation, which is working to restore the tree to flourish as it once did.

Fitzsimmons said that will likely receive a lot longer than many chestnut enthusiasts had hoped. Researchers have hit roadblocks with attempts to breed or genetically modify a version that can withstand the invasive blight that has hammered the species since the early 1900s. If and when they do discover the correct variety, they’ll require to figure out how to plant it and assist it thrive in forests that are under pressure from climate transformation, globalization and advancement.

Once a hallmark of forests from Georgia to recent England, American chestnuts now exist mostly as a vast network of root systems underground, sending up shoots. They develop for a period, but the fungal blight takes hold when the trees commence maturing. East Asian varieties, like those that introduced the blight in the first place, are immune to the blight, and produce most of the edible chestnuts for fall and winter snacking.

Still, American chestnut trees are better suited for timber, they’re culturally loved by people all over North America and they used to be an significant species for the ecological health of forests, providing a reliable source of nutritious food and shelter for wildlife and humans alike. “It was really a pretty significant species to misplace,” said Amy Brunner, an associate professor at Virginia Tech who works on the tree’s genetics. “The more diversity you misplace, the less resilient that forest ecosystem is.”

The American Chestnut Foundation, among others, has been trying for decades to breed a hybrid that is mostly American in genetics but with the fungus-fighting traits of the Chinese type. Fitzsimmons said breeders have learned just how challenging that is — blight resistance involves several different genes and it has proven challenging to divide them from the traits that distinguish Chinese chestnuts.

To speed the procedure, some scientists have been working on genetically modifying American chestnuts to view if they can boost their immunity that way instead. But advancement was delayed by a recent mix-up involving two versions of a genetically modified American chestnut that scientists at State University of recent York had hoped could get through the regulatory procedure as soon as this year.

“It benevolent of stinks that it happened because now it’s taking a little bit longer than we had hoped,” said Linda McGuigan, a research back specialist at the university. But scientists there and elsewhere are continuing to pursue many avenues.

“I don’t ponder you will get there, to all you desire, without both,” Brunner said, referring to the two main methods of breeding and genetic modification. Breeding is vital for achieving enough genetic diversity for trees to adjust to a changing globe, she said, but added that she thinks some genetic manipulation will be needed to get to enough blight resistance for American chestnuts to stand a chance.

Meanwhile, other scientists are working on projects to tackle another large test ahead for chestnuts: where to plant them. If a successful tree is cobbled together with genes taken from trees from Tennessee to recent York, where would it have the best chance at surviving, given how a warming earth is changing habitat around the globe?

A throng at Virginia Tech published a document this summer to try to respond that question. They looked at 32 climate variables and compared them to projected upcoming climates, then calculated the shortest distance that regionally specific American chestnuts would have to shift to offset warming. The concept was to one day assist them survive a recent climate while keeping them as close as feasible to where they once thrived.

“I don’t ponder it’s hyperbolic to declare it’s revolutionary” for teams at The American Chestnut Foundation, said Fitzsimmons, who contributed data to the assignment. She said the assignment will assist them better figure out where to collect genes from the immature trees that remain across the country.

Tom Kimmerer, a forest scientist who taught at the University of Kentucky, is working on a book about trees including the American chestnut. Kimmerer, who was not involved in the research, called it “robust and well supported” and “critically significant to the achievement of the chestnut.”

Stacy Clark, a research forester at the U.S. Forest Service, said the findings are useful, but added that they require to be backed up with real-globe experiments. “I ponder with advancements in genetics, they can probably get pretty quick data off of those field trials. But still, all of that takes period and attempt, correct?”

For now, forest scientists recognize their work might not pay off in their lifetimes. It’s a lesson that became obvious for the throng when pioneering chestnut restoration experts invoice Powell and Chuck Maynard both died in the history 13 months. McGuigan supported both of their research for years as lab manager at SUNY’s college of environmental science and forestry.

“The assignment moves on, lives on. And we integrity their recollection,” McGuigan said. “I desire to do something excellent for the upcoming, for my children.”

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pursue Melina Walling on X @MelinaWalling and Bluesky @melinawalling.bsky.social.

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