From UNH: American chestnut has been under attack for a century from a persistent chestnut blight that has killed trees from Georgia to Maine and west to the Ohio River Valley. A potentially blight-resistant American chestnut tree plantation planned for the University of New Hampshire may one day mean that the tree that was once prominent in eastern North America — numbering in the billions — may again be common in this region’s forests.
UNH is in the initial stages of establishing an American chestnut tree plantation at Kingman Farm in Madbury, on the Seacoast. The effort is a joint project between the NH Agricultural Experiment Station and The American Chestnut Foundation. Steve Eisenhaure, land use coordinator with the UNH Office of Woodlands and Natural Areas, is overseeing the one-acre project. UNH plans to plant 350 trees at the farm.
“Chestnut trees still can be found in our area, but they no longer reach the mature stage because of the blight,” said Eisenhaure, who manages UNH’s 3,500 acres of wooded area.
The American chestnut was an important tree to the Eastern deciduous forest landscape. The trees grew very large and produce wood that resisted rot and was highly valued for building and to make furniture. The nuts provided food for people and were a critical food source for a wide variety of animals from birds to bears. The loss of American chestnut in the Eastern forests drastically changed the diversity of these ecosystems.
Chestnut blight, a fungal disease, has hit hard American chestnuts and was first seen in eastern North America about 100 years ago. Chestnut blight is believed to have been accidentally introduced into North America on imported Asiatic chestnut trees in the late 1800s and was first identified as an exotic pathogen in 1904.
“We are planning to plant trees that have been crossbred with blight-resistant strains of the tree. This is the first step in developing an area that our researchers in the future can study and draw material from,” Eisenhaure said.
Researchers will plant American chestnuts that have been bred to incorporate the blight resistance of the Chinese chestnut, while retaining as much of the American chestnut’s natural character as possible, using the backcross method of breeding. This method takes advantage of the Asiatic chestnut tree’s resistance to chestnut blight but allows for the incorporation of more American chestnut genetics through multiple generations of breeding. By introducing the blight-resistant genes from the Chinese chestnut into the American chestnut, and then repeatedly crossbreeding subsequent blight-resistant American chestnuts with additional native American chestnuts, The American Chestnut Foundation has developed a population of trees that are between 94 and 97 percent Americanchestnut and potentially blight-resistant enough to survive long-term in the forest. These trees took more than three decades of careful breeding to produce and are what will be planted at Kingman Farm.
The American chestnut tree plantation will be UNH’s fourth research plantation at Kingman Farm. The farm already has white pine seed, red spruce, and pitch pine plantations that are used by researchers with UNH and the U.S. Forest Service as well as for outreach and education.
Formed in 1983, The American Chestnut Foundation has initiated a complex breeding program to transfer genes containing disease resistance from Asian chestnut species to American chestnut. Since then, the foundation has produced the first generation of trees that are 96 percent American chestnut but contain Asiatic genes for blight resistance. Now supported by more than 5,000 members and hundreds of volunteers in 23 states, the organization is planting and testing offspring of those trees as it continues to build and improve its breeding population. With the aid of many partner organizations, the foundation is leading the restoration of an iconic species once on the brink of extinction. The American Chestnut Foundation is headquartered in Asheville, NC, with three regional offices in Charlottesville, VA, South Burlington, VT, and State College, PA. The organization’s research farm in Meadowview, VA, has more than 50,000 trees planted in various stages of development.