A long-running effort to bring back one of the giants of New England’s forests arrived in Concord on Friday, as six American chestnut trees, cross-bred for generations to resist the disease that virtually exterminated the species, were planted on land owned by St. Paul’s School.
The planting fits into the land-management goals of the school and of its neighbor, the New Hampshire Audubon Society, which manages the property the trees now call home.
“We have a policy to plant native whenever possible in landscaping, and this fits right in with that. The potential that the American chestnut could be reforested in this area is really appealing,” said Nick Babladelis, environmental steward for St. Paul’s School.
Potential is the right word, because there’s no guarantee that the plantings will survive, even though they are much hardier than trees in the wild.
“We do not have an absolutely blight-resistant tree,” said Curt Laffin, of Hudson, a member of the American Chestnut Foundation who has been a driving force behind similar plantings in southern New Hampshire. He noted, for example, that eight similar trees were planted at Benson Park in Hudson five years ago, and three have already died from the fungal disease called chestnut blight.
The American chestnut may have been the most important tree species for colonial settlers in the Northeast, both because of the great number of wildlife-supporting nuts that it produced and because its straight-grained wood, resistant to rotting, was valuable for everything from furniture to fence posts, according to experts. As much as one-third of the hardwood in Appalachian forests were chestnut until a blight caused by a fungus carried on imported Chinese chestnut trees began spreading in the early 20th century. By World War II, the tree was almost wiped out.
Today, an occasional young American chestnut tree can be found in the woods, often growing out of the stump of a dead tree. On rare occasions when a mature chestnut tree is found, usually because it is so isolated that the fungus has not been spread to it from nearby trees, ACF volunteers collect the chestnuts and use them for restoration efforts.
The St. Paul’s trees are sixth-generation backcross, produced from a line of American chestnut trees, which have a tall, shape and huge nut production. They were bred with Chinese chestnut trees, which are smaller and less productive but naturally resistant to the Asian disease.
By cross-breeding the two species, planting the resulting nuts, choosing the hardiest members of that generation and cross-breeding those with American chestnuts, then repeating the process over and over, ACF is trying to develop a strain that looks and acts like an American chestnut tree but can shrug off the fungus. It’s slow going, since it takes several years for a generation to produce nuts.
Similar cross-breeding programs are going on across the Northeast in an attempt to develop resistant strains that also respond well to local environments. The longest-running ACF program in Virginia has begun to distribute nuts from its sixth-generation trees for planting in the wild.
There are other efforts to create a blight-resistant American chestnut, including a program involving genetic modification being run by the State University of New York.
Laffin said the St. Paul’s School planting is of particular interest to the New Hampshire/Vermont chapter of ACF because the land was recently clear-cut as part of land management at the school. Other plantings in the two states have taken place in fields, a very different environment.
The St. Paul’s School planting has the advantage of being very public, because there are popular hiking trails in the area.
“Through Audubon, we want to learn how best to do this, so that we can publicize more that we’re available to put in these plantings for towns, organizations, anyone willing to take care of the trees,” Laffin said. “There is responsibility on part of the host. They have to find a site and it’s a long-time commitment, to make sure they’re protected from deer, if they need fertilization, report back to us how they’re doing.”
(David Brooks can be reached at 369-3313 or dbrooks@cmonitor.com or on Twitter @GraniteGeek)