A lot of native nut trees in Eastern North America need fire to regenerate. Oaks, hickories, black walnuts, and hazelnuts all have a longstanding relationship with human fire, and in recent decades foresters have started putting low-intensity prescribed fires back into the woods—and just to be clear this isn’t about lighting individual trees on fire, it’s about burning the ground, to keep the woods open enough that these critical food species will continue regenerating. But one nut we don’t know much about when it comes to fire is chestnut trees. The American chestnut was rendered functionally extinct by a blight in the early 1900s, and as efforts to get a hybrid or genetically modified chestnut back into our forests intensify, researchers at the SUNY College of Environmental Science and Forestry are asking: how will these trees respond to burning? Maya Neiesz Kutch is a graduate student in the program:
Maya: What we can kind of look at right now, is just the physical, physiological traits of the American chestnut and comparing that to a lot of other species that we know a lot more about and their fire history and see how—whether the American Chestnut looks like these other fire-tolerant species or looks like a fire intolerant species.
Fire intolerant species don’t survive fires well, while fire tolerant species often have traits that help them not just survive but even encourage the woods around them to burn.
Maya: The American chestnut has highly flammable leaves. So that you know is obviously is very interesting. And so then I wanted to specifically look at bark traits because bark is another very important factor. You can imagine that a tree with very thick bark would have a lot more insulative capacity to protect the inside of the tree from getting damaged from fire.
Most American chestnuts alive today are very young, so it’s hard to look at their mature bark. The way the blight works, the trees don’t die back completely, but resprout continually from their roots—so there are a lot of tiny American chestnut trees in our forests. Maria Loughran, a colleague of Maya’s, says we do have pictures and wood from older, dead American chestnut trees, and these are telling.
Maria: So many oaks have like really thick, knotty bark, which is true for large remnant chestnuts that we see.
This thick bark is another marker of fire tolerance. And so is resprouting quickly.
Maria: They also grow really fast there are a lot of stories about like how quickly they would grow especially when they are in kind of high light environments which is very similar to oaks.
Like the other fire-adapted nut trees, American chestnuts like the sunny, open areas created by fire and other disturbances. And overall, the evidence that’s been emerging in recent decades suggests that American chestnuts and the other species breeders are combining them with—Chinese and Asian and European trees—all have at least some fire adaptations. So, in her research work, Maria has started actually burning the ground in test plots growing young American chestnut trees.
Maria: We planted about 250 just wild-type American chestnuts, and then we were able to burn them, and then kind of re-monitor their growth.
They almost all survived—which just reinforced to Maria and Maya the importance of monitoring the fire ecology of American chestnuts in real life. Their ability to withstand fire might seem like a small or weird detail to focus on in the big picture as we try to bring back this iconic species—but Maya says, it’s important because of the history of the relationship between humans, fire, and nut trees.
Maya: There are multiple papers on how with the arrival of Indigenous peoples that we can see in like the records, there's an increase in fire correlated with that and also an increase in chestnut presence. There’s a lot of research that shows that Indigenous people were encouraging fire for many reasons, but one of those was likely to encourage a lot of those nut groves that are these fire-resistant species.
Research on leaf flammability: https://www.researchgate.net/publication/329766502_Resurrecting_the_Lost_Flames_of_American_Chestnut
Research on the history of the American chestnut and fire: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.3267
Research on the connection between Indigenous burning and chestnut spread: https://www.jstor.org/stable/4033982
Comparing prescribed fire effects in American chestnuts and closely related oaks:
https://www.fs.usda.gov/nrs/pubs/gtr/gtr_nrs-p-142papers/21-belair-et-al_2014-CHFC.pdf
Elspeth Hay is the author of Feed Us with Trees: Nuts and the Future of Food, released July 2025.
