The American Chestnut
Susan Freinkel, in her excellent book “American Chestnut: The Life, Death, and Rebirth of a Perfect Tree,” describes how, in the fall, when the nuts were sometimes inches deep on the ground, families used to gather them for their own use and to sell. Livestock was let loose to eat their fill. People who didn’t eat chestnuts often ate chestnut-fed venison or squirrel. Furniture, fence posts and utility poles were made of the long, straight, rot-resistant timber. In some places, one in four forest trees was a chestnut, and the tallest stood 12 stories high.
Then a fungus killed almost all of them. The chestnut blight was first spotted in 1904 and is believed to have arrived here in Asian chestnut trees, which have some resistance to it. American chestnuts have none, and all but a few hundred of the 3 to 4 billion trees were wiped out in just a couple of decades.
Three to 4 billion. It’s hard to get your arms around a number that big, so let’s convert it to something useful: food. A mature tree can produce several hundred pounds of nuts (the record is more than 1,000 pounds); about 70% of that weight in actual nutmeat. For the sake of being conservative and working with round numbers, let’s call it 100 pounds of nutmeat per tree, at about 1,000 calories per pound or 100,000 calories per tree. So 10 trees would provide the million calories (give or take) one person eats in a year.
Here’s what that means: If we still had those 3 to 4 billion trees, they would meet 100 percent of the caloric needs of today’s entire American population of just over 300 million. They could feed every last one of us.
A readily available supply of high-quality, good-tasting food, growing out there in the woods, might put it in more people’s grasp. Thanks to a group of scientists at the State University of New York College of Environmental Science and Forestry, headed by Bill Powell and Chuck Maynard, it could happen. On Nov. 4, 2014 they announced that they had bred a blight-resistant American chestnut by introducing a gene from wheat.
Blight kills trees by producing oxalic acid. Wheat has a natural defense against oxalic acid; the plant can break it down into benign components. It turns out that a single gene is responsible for that function, and inserting that single gene into the American chestnut genome made the tree resistant.
Over the past year, I’ve written quite a bit about genetically modified organisms (GMOs), and I’m going to put that issue on the shelf for a while. But I couldn’t do it without mentioning the blight-resistant American chestnut, because it’s everything that the GMOs now in our food supply are not. It wasn’t created for personal profit or for the benefit of corporations or farmers. It contributes to a wholesome, healthful diet. And it’s intended solely for the public good.
There has been an effort — ongoing in the 100 years since the blight — to create blight-resistant American chestnuts by cross-breeding with Chinese chestnuts, and the American Chestnut Foundation has had some success on that front, but it hasn’t yet achieved its goal. Powell told me he’s glad others are taking a different approach, because having the trees from both programs out there in the forest would increase the genetic diversity and the chance that American chestnuts will thrive. Chinese chestnut trees can grow in some parts of the country, but they don’t have the cold-resistance for the American chestnut’s range, and they grow wide rather than tall, making them ill-suited for forests.
Powell and Maynard anticipate that getting approval from the USDA, FDA and EPA will take at least five years, and they’re spending that time trying to raise 10,000 blight-resistant chestnut seedlings. When the approvals are in, those 10,000 will be the American chestnut’s re-introduction into our lives.
Repopulating our woods — and even our yards, our commons and our courthouse lawns — with American chestnuts would put a versatile, nutritious, easily harvested food source within reach of just about everyone. For those living on the margins, it could be a very real hedge against want. For everyone, it could be a hedge against distancing ourselves from our food, which can be the first step toward a diet low in the whole foods that virtually every public health authority tells us we should eat more of.
Most people don’t have the time or flexibility to hunt, gather and grow all those things, and even one or two of them can be a stretch. But almost everyone could take the kids into the woods one beautiful fall weekend to gather chestnuts. This Thanksgiving, I hope you’ll join me in congratulating the scientists who are working hard to make it possible.