Chestnuts and TACF make the New York Times (blog)
This photo is from the West Salem, Wisconsin, stand of chestnuts. Of all my work experiences, seeing this stand, before the blight hit it, was one of the most soul-stirring and memorable. If anyone has photos that show the stand from that time period, please let me know, they weren’t easy to find on the internet. As you can see from this photo, it’s hard to get a feeling for what the stand was like from a picture as the trees were so tall.
Here’s a link to the whole story, below is just a snippet. It’s also interesting to see the chestnuts still in the understory in Connecticut and Massachusetts after all these years. If anyone has photos of those to share, that would be great. Please send to firstname.lastname@example.org.
The New York Times
Sara Fitzsimmons, the regional science coordinator for the American Chestnut Foundation, studies a canker — a symptom of the chestnut blight that killed billions of American trees in the 20th century — on a seven-year-old American chestnut at the arboretum at Penn State.
Old swaths of Appalachian forest land left barren by decades of coal mining may find their past is their future, if efforts to restore the American chestnut tree in reclaimed coal fields are successful.
Over the next three years, more than 360 acres in Pennsylvania, West Virginia, Virginia, Kentucky and Tennessee will be planted with a variety of American chestnut trees bred to resist chestnut blight. The blight is a fungus that entered the United States around the year 1900 on imported Asian chestnut trees and destroyed about 4 billion native hosts by 1955.
The $1.1 million project — still largely an experiment — represents three decades of innovative breeding by the American Chestnut Foundation and its partners, which also have been planting restoration trees in national forests and on other public lands.
The trees were cultivated at the foundation’s Meadowview, Virginia research farms, as Michael Tortorello reported in his Thanksgiving-season exploration into the life, times and taste of the nut associated with winter holiday feasts and urban sidewalk vendors.
The process involves crossing an American with a Chinese chestnut tree to create half Chinese-half American progeny, then backcrossing several subsequent generations to American chestnuts to cut Chinese characteristics first by one quarter, then again by an eighth and a sixteenth.
As Dr. Frederick V. Hebard, the foundation’s chief scientist, explained. “We diluted out all the traits of the Chinese chestnut except for blight resistance, for which we selected at each backcross by inoculating the trees with the blight fungus.”
“Whenever we backcrossed to the American chestnut, the trees inherited genes for susceptibility to the blight from the American parent. They also had a chance of inheriting the blight resistant gene from the Chinese side. But when we inter-crossed them to each other, they had a chance of inheriting blight resistance from both parents and eliminating the genes for susceptibility,” he said.
Planting American chestnuts in the wild is a major milestone, but restoration work is a long-term process involving additional research and backcross breeding, said Sara Fitzsimmons, the foundation’s regional science coordinator, who works at Pennsylvania State University’s campus in State College.
“We’ve reached the point where we need to get these trees into the woods and see how they perform,” she said. “The public thinks you go through a pipeline and you have a magic tree and it’s the ‘be all’ and ‘end all’ and that’s not really true.”
“While we’re optimistic we have great lines coming out of the pipeline” from the Meadowview farms, she said, “we’re still working on a lot of things, like regional adaptability.” That “will take another 10 to 15 years to perfect,” she added.
Because the foundation is eager to gauge the trees’ disease-hardiness, scientists will probably inoculate some specimens with fungus after they are planted, while letting exposure occur naturally to others, said the foundation’s chief executive, Bryan Burhans.
And exposure is likely, given the blight’s presence in the environment, he said. “It’s ubiquitous and easily transmitted by wind” or on the feet of birds. “If there’s a wound or weak site,” he said, “it enters a tree that way.”
The disease appears as orange-yellow spots on branches, then as a canker that eventually girdles the trunk, killing everything above it, Mr. Burhans said. “The tree dies pretty quickly.”
Although the vast majority of American chestnut trees have succumbed to blight, some stands have survived, including some in Braceville, Ohio, and in the Allegheny National Forest in northwest Pennsylvania. The largest remaining stand of American chestnuts — 2,500 trees near West Salem, Wisconsin — was found to have blight about 10 years ago.
But the foundation keeps trying to breed its way to a blight-proof American chestnut tree. And it strives to make its work known to a generation that has little or no memory of the trees that once dominated the eastern landscape. The foundation’s volunteer corps began demonstration plantings in 2005 at schools, public parks, and other high-profile venues, like the National Mall in Washington D.C. and the New York Botanical Garden in the Bronx.
Here’s a really nice story by Susan Freinkel from NRDC on restoring chestnut. It’s always interesting what people agree on.(!)