A hundred years ago the hardwood forested landscape of the northeastern and midwestern United States was dominated by enormous and prolific American chestnut trees. Dozens of bird and mammal species feasted upon the rich rich nutrients of the chestnuts, even as our ancestors celebrated the pleasures of “chestnuts roasting on an open fire.” Because the tree bears a consistent crop year in and year out, it was a far more dependable food source than most other species yielding nuts and acorns, which frequently bear heavily only in alternate years.

The chestnut was also a beautiful shade tree, prized for its timber: with rapid straight growth, even grain and excellent resistant to rot.

But in 1904 a fungal disease, chestnut blight, was inadvertently imported along with Asian chestnut seedlings. Unlike its Asian relative which tolerates the fungus that is native to its range, the previously unexposed American chestnut cannot survive infection. The fungus enters the tree through injuries in the outer bark, then spreads into the xylem and phloem layers which transport nutrients from leaves to roots and back.

Within 40 years the American chestnut was nearly extinct throughout its once vast range. Only a few isolated mature trees remain, and the pathetic stumps of once majestic specimens which still sprout small shoots that grow briefly until they too succumb to the blight.

But scientists at Purdue University have been developing blight resistant hybrids by crossing the few surviving American chestnuts with their Asian cousins. Once they have secured highly resistant strains they then work to produce trees that are genetically 94 percent American and 6 percent Asian hybris.

By 2006 they expect to release a limited number of blight-resistant chestnut seeds to the public, with hopes of significant plantings to follow over the next decade.

With good fortune the American chestnut will once again grace our nation’s landscape.
(Purdue University)

–From the April 2004 Austin Review KB