Tree Species Rescued by Duke Farms, Rutgers

Courtesy of Rutgers Today

The American chestnut tree once thrived in the eastern half of the United States, providing food and shade in forests from Maine to Florida, and as far west as the Ohio Valley. Prized for its durable lumber put to a variety of uses from fine furniture and musical instruments to railroad ties, the tree has been honored in American culture through songs and poetry.

But in the early 1900s, a fungus brought over to the United States on trees imported from Asia began infecting the American chestnut. By the 1950s, chestnut blight had nearly wiped out the entire species.

“The fungus spread like crazy, and what was one of the most valuable trees in eastern North America became like the Jedi knights: extinct,’’ said Steven Handel, a professor in the Department of Ecology, Evolution and Natural Resources at Rutgers.

The chestnuts now roasted on New York City streets during the holiday season are Chinese chestnuts, supposedly not as sweet as the chestnuts that were wiped from forests by the blight, Handel said.

As scientists work to develop a hybrid that is resistant to the fungus, Rutgers ecologists are playing a role in the multistate effort to reintroduce the American chestnut in the forest through their work at Duke Farms, a 2,700-acre estate in Somerset County. 

“One of the challenges of reintroducing the chestnut in the eastern forest is where do you put them,’’ said Christina Kaunzinger, a senior ecologist with Rutgers’ Center for Urban Restoration Ecology.

Efforts to remove nonnative plants at Duke Farms provided the perfect opportunity. Duke Farms has been working with Rutgers on a new mission to transform the Hillsborough estate built by the wealthy tobacco and hydropower magnate James Buchanan Duke into an education and research center. The goal is to teach visitors how be good stewards of the land and develop an appreciation of natural landscapes and native plants. 

As part of the new mission, Duke Farms removed thousands of plants from the property. Cutting down invasive species that shade and crowd out the native plants – which provide a more valuable source of food for the local wildlife–created gaps in the forest.

“Forests are full of oaks and hickory where the chestnuts were,’’ Kaunzinger said. “They have grown in and you don’t want to cut down native trees to plant to plant chestnuts. That is why it was an interesting idea to use the gaps created through invasive species management.’’

The American Chestnut Foundation’s Meadowview Research Farms in Virginia and its Pennsylvania chapter at Penn State supplied the seeds that were planted in 10 gaps in the forests. Rutgers is growing American Chestnuts–to study when the trees are struck by the blight – along side Chinese chestnuts and hybrids of the American chestnut that is one-sixteenth Chinese chestnut. Ecologists planted 270 chestnut trees at Duke Farms in the fall of 2010 and more than half have survived.

The project, which cost $37,000 so far, has been funded by the American Chestnut Foundation, the Duke Farms Foundation and donations from Rutgers alumni.

Rutgers ecologists will compare the growth and survival rates of the different varieties of chestnut trees and collect data on when the trees are attacked by the fungus, as well as the severity of the blight.

“The American chestnuts will definitely get the blight,’’ Kaunzinger said. “The others, we don’t know. We are looking at whether these hybrids are successful, and whether they survive to reproduction. If they can do that, they can produce seed and spread throughout the forest.’’

The goal of the research at Duke Farms is to investigate whether planting chestnuts trees in gaps in the forest created by removing invasive species is a promising method to reintroduce the nearly extinct species. If Rutgers is successful, the hope is that other land managers in the eastern United States will get involved in the project.

“The ultimate goal is to have chestnut trees become a component of the eastern forest again,’’ Kaunzinger said. “It’s like redressing the wrong done–bringing one tree back from the brink of extinction.”