SCIENCE: Hybrid Chestnut Trees Hold Promise as Carbon Sponges

By Katie Mattern

WASHINGTON, Jun 16 (IPS) - Reducing carbon levels in the atmosphere may be as simple as planting a new breed of hybridised chestnut trees, according to a new study by Purdue University Associate Professor Douglass Jacobs.

The hybrid American chestnut tree, which is mixed with a similar and more disease-resistant Chinese chestnut tree, has been found to grow faster than other chestnut trees and retain carbon for a longer period of time, including after its death.

The American chestnut has been facing extinction since the chestnut blight was introduced in the early 1900s, according to Jacobs. But scientists previously had little incentive to bring it back because of its susceptibility to disease.

The decline of the tree has coincided with the rapid rise in the use of electricity and fuel-based transport that made the U.S. carbon output skyrocket in the twentieth century, contributing to the U.S.’s longtime top slot among carbon emitters. However, the new hope for mitigating climate change is not ready to be planted in forests across the country just yet. "We're really quite close to having a blight-resistant hybrid that can be reintroduced into eastern forests," Jacobs said in a press release from Purdue.

"But because the American chestnut has been absent from our forests for so long now, we really don't know much about the species at all." A fungus that nearly made the trees extinct 50 years ago affected chestnuts from the northeastern U.S. all the way to southern states like Alabama.

However, the new trees, which will hopefully withstand another similar disease, are not going to be ready to plant across the U.S. for another decade. Jacobs and his team plan to plant the trees in forests or former agricultural fields that are being transformed into forested land.

Jacobs studied a population of remaining American chestnuts across southwestern Wisconsin and compared them to other varieties of chestnut trees. These trees were unaffected by the fungus because of their distance from the rest of their species.

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