Skip to content
Link copied to clipboard

Researchers and volunteers hope to restore the American chestnut, the former king of Pennsylvania’s forests.

American chestnut trees, once numbering in the billions, have been decimated by a fungus called blight. Today there are approximately 435 million but few reproduce.

Mike Manes, 78, looks for chestnut trees on the Pulpit Rock and Pinnacle Loop trail in Hamburg, PA on Wednesday, June 8, 2022. The chestnut tree population is being decimated by a blight that first appeared in 1904. Manes is a volunteer for the Pennsylvania chapter of the American Chestnut Foundation which is working to restore eastern U.S. forests with healthy American chestnuts trees.
Mike Manes, 78, looks for chestnut trees on the Pulpit Rock and Pinnacle Loop trail in Hamburg, PA on Wednesday, June 8, 2022. The chestnut tree population is being decimated by a blight that first appeared in 1904. Manes is a volunteer for the Pennsylvania chapter of the American Chestnut Foundation which is working to restore eastern U.S. forests with healthy American chestnuts trees.Read moreErin Blewett

Sunlight filtered through the overstory of a thick Pennsylvania forest and a few rays fell upon the long, serrated leaves of the American chestnut trees down below.

The higher Mike Manes, 78, hiked, here on the Appalachian Trail, the more chestnut trees he saw. Most weren’t very tall or wide, but they weren’t exactly young either. These trees, once the king of American forests in the Northeast, weren’t born from new seeds. They had risen from older roots below the soil, thin sprouts trying to reclaim their kingdom from an unstoppable foe they’ve been battling for over a century.

“I see one over there, but it’s dead,” said Manes, a volunteer with the American Chestnut Foundation.

In the 19th century, there were up to 4 billion chestnut trees in the United States, making them the most dominant hardwood tree in the East. The Indigenous people in those lands called them the “grandfathers,” as they often grew over 100 feet tall and dominated the canopy. Historians called chestnuts a “cradle-to-grave” tree, their rot-resistant wood once used for building cribs, homes, and coffins for centuries. Its seeds, encased in large prickly burrs, fed just about every living thing in the nation.

“They were the most dominant tree in the Pennsylvania woods,” Manes said.

In 1904, however, caretakers at the Bronx Zoo discovered a small, rust-colored fungus growing on the bark of chestnut trees there. Soon, those trees were dead, as the pathogenic fungus known simply as “blight” found its way through cracks in the bark and bore into the wood, destroying the trees’ vascular system and creating large cankers in places where it tried to fight back. Chestnuts killed by blight often look as if a bear used them for a scratching post or a bomb went off inside them, their bark dry and shredded, their leaves gone.

Blight traveled out in circles from the Bronx, with airborne spores affecting chestnut trees elsewhere in New York, New Jersey, and Connecticut. In 1909, the Buffalo Courier reported that 10,000 chestnuts had died in Brooklyn Forest Park. In Fairmount Park, according to a 1911 Inquirer story, 1,000 chestnut trees died from blight.

Scientists, at the time, concluded that the blight had come to the U.S. in the late 1800s from imports of Japanese chestnut trees used for food and ornamental purposes. Japanese and Chinese chestnuts have a natural resistance to the blight.

Soon blight spread even further, traveling west into Ohio and down the Appalachian Mountains to kill trees in the Southeast. Scientists and foresters struggled to find solutions. Pennsylvania was one of the first states to take action, forming the PA Commission on Chestnut Tree Blight in 1912. The state spent $240,000 on the two-year research project at the time.

“None of it worked,” said Sara Fitzsimmons, a restoration coordinator with the American Chestnut Foundation.

In 1911, the Brooklyn Daily Eagle proclaimed that “all living chestnut trees in the Eastern part of the United States are doomed.”

The USDA, when it was evident that Pennsylvania’s methods weren’t working, sent researchers to Asia to study chestnut varieties there.

Fitzsimmons said Chinese chestnut trees are fairly common in the Eastern United States today but are not considered invasive. They can still get blight.

“There’s no such thing as full immunity with chestnut trees,” she said. “It ranges from high resistance to none.”

Today, there are approximately 435 million American chestnut trees in the country and most are killed by blight long before they reach maturity. The American chestnut, today, is considered “functionally extinct.” Tall, mature American chestnuts that still produce flowers, and possibly reproduce, are rare and studied intensely. Some of those trees exist in Pennsylvania, including one majestic survivor in York County.

“We have cloned some of them to use for further study,” Fitzsimmons said.

The American Chestnut Foundation, founded in Asheville, N.C., in 1983, is the leading advocacy and research group for the tree, partnering on research and history projects with universities including Penn State, SUNY College of Environmental Science and Forestry in Syracuse, and the University of Tennessee at Chattanooga.

Fitzsimmons, who has worked out of Penn State since 2003, is involved in a series of projects aimed at engineering blight-resistant chestnut trees. One way to save the American chestnut could be hybridization, the cross-pollination of American chestnuts with Japanese and Chinese varieties. Another technique being used in Syracuse involves the addition of new genes to the American chestnut. One gene, called OxO, breaks down the acid that blight uses to attack the tree. The American Chestnut Tree foundation made an animated video to explain it.

At Penn State, researchers can then breed Chinese hybrids with clones infused with the resistant gene. On a recent late spring afternoon at the university’s arboretum, researchers were high up in an industrial lift, covering chestnut tree flowers with waxy, paper bags to prevent any unwanted pollination. Later, they would take their own, preferred pollen from potentially blight-resistant trees and pollinate them.

Fitzsimmons said Penn State helped plant 5,000 chestnut trees this spring, many of them starting off in a greenhouse around the corner from Beaver Stadium. She said many of the saplings would be purposely infected with blight, even thought the fungus is likely already in the air there.

“We want to see how these trees react,” she said.

Trees that show promise will be planted in the arboretum a few miles away. If those thrive, they could represent a future in the nation’s forests.

When asked why so much effort has been put into saving one tree, Fitzsimmons said it’s both science and sentiment. She grew up in southern West Virginia, where her “paw paw” salvaged chestnut panels from shuttered, one-room schoolhouses. They later lined her basement walls.

“A lot of people have this familial connection with the tree. It’s almost innate from their youth,” she said. “It was used so extensively, especially in the southern Appalachian states and for it to be erased in one generation, in what is essentially a blink of an eye, resonated with people. "

On the Appalachian Trail, Manes — a lifelong hiker who hasn’t lost his Brooklyn accent — and his wife, Kieu, counted 4,631 chestnut trees three feet or taller within 15 feet of the trail between Port Royal and the Delaware River. The couple covered the 75-mile distance as part of the Appalachian Trail MEGA-Transect Chestnut Project. He says there may be another census a decade or so from now.

“I’m 78, so I don’t know if I’ll be a part of that one,” he said, during a break in his hike. “But I hope there will be more.”