Tiny sapling, mighty hope at Independence Hall

A pint-size sapling will be planted at Independence Hall tomorrow, bringing with it an outsize hope - that a mighty tree that all but disappeared 60 years ago will someday find its way back to the East Coast forests and hillsides it once dominated.

The sapling is a new, improved American chestnut. It will be planted in the square behind the hall, a place so rich you can just imagine Benjamin Franklin and untold others making history here, enveloped in the shade of these beautiful native trees.

But this three-footer is a newsmaker in its own right.

It belongs to the latest - and most promising - generation of American chestnut, a hybrid comprising 94 percent American and 6 percent Chinese chestnut-tree genes. It combines the long, elegant American look with Chinese resistance to the blight that wiped out four billion American specimens between 1904 and 1950.

Chestnut lovers hope this new hybrid, in the works since 1983, will survive in the short run, thrive in the long run, and eventually restore chestnuts to the landscape from Maine to Alabama and west to Ohio.

Often referred to as "king of the forest" and "redwood of the East," the American chestnut historically made up 25 percent of the forests in its range, more in Pennsylvania than any other state. In Bucks County, fully half the trees were chestnuts.

"Pennsylvania was the premiere chestnut state, and when blight struck, the state was decimated," said Marshal T. Case, a Drexel Hill native and president emeritus of the American Chestnut Foundation, which has spearheaded the breeding program.

Last year, the foundation teamed up with the University of Tennessee and the U.S. Forest Service to test-plant hundreds of the "94 percent" hybrids in three national forests in the South. So far, so good, and hundreds more are expected to be planted in national forests in the future.

Planting one in Independence Square was the idea of Susan J. Edens, cultural landscape architect for Independence National Historic Park. She says she got the idea after reading a 2008 Inquirer story about two earlier hybrids that were installed in a new arboretum at Chestnut Hill Academy.

"We used to have American chestnuts here," Edens said, during a walkabout in Independence Square that revealed about 80 elms, oaks, maples, London planes, even a massive 133-year-old tree-of-heaven, a weed tree - but no American chestnut.

In the 1780s, when Samuel Vaughn, a British friend of Franklin's, drew up the first landscape plan for the square, two American chestnuts were among hundreds of trees planted there. It's conceivable they protected and cooled the crowds attending Frederick Douglass' antislavery rally in August 1844 or witnessing Susan B. Anthony interrupting Centennial ceremonies with her Declaration of the Rights of Women on July 4, 1876.

So much history. "I think it's super that we'll get an American chestnut again," Edens said. "It was such a major tree."

Castanea dentate, or American chestnut, was called "Mighty Giant," for its 100-foot height and five-foot diameter, and "cradle-to-grave tree," because its strong, rot-resistant, light wood was used to make cradles and coffins and everything in between. That includes railroad ties, telephone poles, shingles, paneling, furniture, and musical instruments.

Sweet-tasting and nutrient-rich, the nuts were an important food source for birds, deer, grouse, wild turkeys, and squirrels - and for humans, especially in Appalachia. Even today, creative chefs use chestnuts to make soup, pasta, risotto, tarts, cakes, and strudels, as well as traditional holiday stuffing.

But this important hardwood tree was highly susceptible to an Asian bark fungus introduced accidentally to this country in the late 1800s, on some imported Chinese chestnut trees planted at the Bronx Zoo. It was discovered in 1904, spreading 50 miles a year.

The disease girdles and kills, leaving only stumps that send out new shoots. They rarely reach more than 20 feet before the infection returns and the tree dies back. So the American chestnut is not extinct; it just lacks critical immunity against a ruthless nonnative disease.

And its plight is not an anomaly. Similar scenarios continue to play out in this country with things such as white pine blister rust, sudden oak death, and most recently, the emerald ash borer, an Asian beetle discovered in Michigan in 2002 and Western Pennsylvania in 2007.

The U.S. Department of Agriculture first adopted regulations for the international plant trade in 1918, partly in response to the chestnut debacle.

Back then, only a few thousand plants were imported annually to the United States. Today, it's more than a half-billion, most from Central America and Europe, with a growing number from East Asia, according to Frank Lowenstein, director of the Nature Conservancy's Forest Health Program.

Only about 2 percent get inspected.

But inspections aren't always the answer. Some diseases are undetectable during latent stages. Insect larvae can be virtually invisible. And some problems take more than a decade to even show up.

"When enough trees have passed away, it becomes obvious something is wrong," Lowenstein said.

The USDA is considering additional rules that would identify risky plant sources abroad and temporarily halt their import until stock is certified as clean. The agency would also work with the domestic nursery industry to screen out potential problems.

One way for consumers to circumvent the whole issue is to plant locally grown, native plants and trees, Lowenstein said.

That would include, in due time and in retooled form, the American chestnut.

From noon to 1 p.m. tomorrow, two American chestnut trees will

be planted in Independence Square behind Independence Hall on the south side of the square.

One tree is the latest and most promising hybrid developed over the last 26 years by breeding and cross-breeding American and Chinese chestnuts. The Chinese trees are naturally resistant to the blight that wiped out four billion of their American counterparts in the first half of the 20th century.

Besides officials from

tree donor Trees NC, the park and foundation, Morris Arboretum,

and Pennsylvania Horticultural Society, others expected at

the planting are Thomas Jefferson and colonial botanist John Bartram. That would be compliments of American Historical Theater.

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