American chestnut

Volunteer B. J. Absher, a professional arborist, climbs the Amherst Chestnut to get a precise “drop line” height measurement of the 150-year-old tree. (Photo courtesy of Eric Wiseman, VA Big Tree Program)

No surprise, I am a promiscuous hugger of trees. But what tree would I drive five hours to embrace? What single species would lure me to the outermost fringe of the Chesapeake Bay watershed, near Lynchburg, VA, where the drainage tips from the James River into the Bay to the Roanoke River into Albemarle Sound?

It had been more than a decade since I visited the rare, old Amherst Chestnut, improbable survivor of the 20th-century ecological catastrophe that eliminated the dominant tree of the Eastern hardwood forests — ending a 12,000-year reign of Castanea dentata, the American chestnut, in less than 50 years.

This winter, I recognized it easily as I battled up a snowy lane to the small pasture where it stands, gnarled and cankered, its crown wracked by storms and a major limb recently split off. But the tree still bears seeds — chestnuts, that is — presumably two or three of the brown nuggets in each of the prickly burs that I could see clinging to branches and littering the ground.

The landowner was good enough to give permission. For 30 years, she and her late husband have been the latest stewards of this specimen, which likely sprouted in the 1870s. The unstoppable fungus, the blight that came with imported Asian chestnuts, was already in this country then. It would be first identified in New York’s Bronx in 1904.

Approximately 4 billion chestnut trees would die from it. It happened so suddenly that scientists who interpret deep cores from the Chesapeake’s sediments can use the disappearance of chestnut pollen (1910–30) as a marker for dating them.

An estimated 430 million native chestnuts still sprout from old roots. But only dozens survive the blight long enough for the trunk to reach 10 inches in diameter, about 30 inches around — this in a species that could be 12 feet across and 37 feet around.

And of these dozens, a mere few of any real stature exist. The Amherst tree is the largest known in Virginia, possibly one of the largest in the entire original range of

C. dentata, stretching from New England to the deep South and as far west as Indiana. Last measured in 2015, it was 4 feet in diameter with a 12-foot circumference, 55 feet high with a spread of 42 feet.

What is the Amherst Chestnut’s secret? Does it, almost alone of billions, have blight resistance that might enable restoration of its kind to kings of the forest again? Is it just in a superb growing environment? Was the blight that attacked it (and it is full of the awful cankers caused by the fungus) somehow weaker than in other trees?

All three of the above may be relevant, says Sara Fitzsimmons, a scientist at Penn State University and director of research for the nonprofit American Chestnut Foundation, dedicated to restoring the species since 1983. But neither the Amherst survivor nor any of the handful of comparable old chestnuts still growing hold any magic answers, she said.

Fitzsimmons and others were cautiously optimistic in 2010, when I wrote an article, Restoring American Chestnuts, for American Forests magazine. Several generations of the foundation’s crossbreeding of resistant Chinese chestnuts with American trees had resulted in a lineage that, it was hoped, would be more than 90% pure native chestnut, with the Chinese level of resistance.

It was good enough for the U.S. Forest Service to begin planting in 2008. While this was an important step in the learning process, neither the hoped-for levels of native purity nor the blight resistance of the hybrid lived up to expectations.

“Resistance is more complicated than we thought,” Fitzsimmons said. Molecular analysis has shown it involves several genes instead of a few. This substantially complicates both crossbreeding efforts and genetic engineering.

The foundation continues to pursue both approaches, as well as a promising third one, known as “hypovirulence.” This involves creating a weakened version of the fungus itself (Cryphonectria parasitica) and inoculating chestnuts with a less-than-lethal infection. It has had success in European chestnuts but, again, seems more complicated with the American species.

“Nothing alone, no one approach, will solve this,” Fitzsimmons said. “Perhaps a mixture will.”

It is a fight well worth fighting, I thought as I admired the Amherst tree. In their glory, chestnuts’ creamy June blooms so festooned Eastern forests that from afar they looked “like a sea with white combers plowing across its surface,” wrote Donald Culross Peattie, a 20th-century U.S. botanist and noted writer.

The annual exuberance of blossoms fed an array of pollinators, and the tree’s plentiful nuts gave settlers, livestock and forest creatures alike a sweet, carroty tasting superfood: lower in fat than many nuts, but high in fiber, vitamin C, protein and carbohydrates. Blooming late, chestnuts avoided the killing frosts that make oaks and hickories a less reliable food supply.

The tree’s lumber was a woodworker’s dream — strong, easily worked and rot-resistant, used in barns and pianos, in split-rail fences and fine furniture. It is also part of our heritage, even our language. Countless place names contain “chestnut” in the eastern United States, and “chestnut” was a common descriptive term for a highly desirable color of women’s hair and men’s beards. Today such uses are fading.

To restore it would repair an ecological calamity equaling the loss of bison, of beavers that controlled North America’s hydrology, and of the passenger pigeon, another ecosystem engineer, whose vast migrating flocks spread seeds in their poop throughout the Eastern forests, ensuring a flow of genetic material with benefits for diversity and resilience.

That’s how important the tree was and could be again. That’s what made it worth the drive to the ends of the Bay watershed, if not to the ends of the Earth.

Tom Horton has written about the Chesapeake Bay for more than 40 years, including eight books. He lives in Salisbury, where he is also a professor of Environmental Studies at Salisbury University.

The views expressed by opinion columnists are not necessarily those of the Bay Journal.

Tom Horton, a Bay Journal columnist, has written many articles and books about the Chesapeake Bay, including Turning the Tide and Island Out of Time. He currently teaches writing and environmental topics at Salisbury University.

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