Thursday, April 7, 2011

American Chestnut Article

Whoops! I meant to post this some months ago. This is my Garden Geek article on American chestnut trees which appeared in the December edition of the Franklin Country Gazette.



The American Chestnut

At Idylbrook Field in Medway, an unmarked path leads through a meadow of wildflowers into rows of cultivated trees. A layman could easily overlook the site as a run-of-the-mill orchard if not for the sign explaining that these are Castanea dentata - American Chestnut.

If the words “American chestnut” don’t give you goose bumps, let me tell you why it should. Schoolchildren revere pandas and elephants and tigers, and most Americans have a soft spot in their heart for our bald national bird. The American Chestnut has similarly been pushed to the brink of extinction.

Castanea dentata is arguably more important a species than any of the charismatic fauna that top the food chain. A scant hundred years without American chestnuts has caused us to forget that East-coast forests used to be chestnut forests. These were New England’s sequoia. American chestnuts could average five feet in diameter and a hundred feet in height, but historic photos demonstrate that they grew much larger than that. On that sign in Idylbrook, a black-and-white photo shows three lumberjacks seated inside of the gash they have made in one tree - a trunk which is easily fifteen feet in diameter.

The chestnut was immensely valued for its wood. The trees grew fast and straight, producing hard wood that was so highly resistant to rot that there are still original chestnut barns standing. In Appalachia, they were known as “cradle-to-grave” trees, because the wood was used for everything, from fences to buildings, to cradles and coffins.

Unlike oak, which only produce a reliable crop of acorns every two to four years, American chestnuts produced copious yearly quantities of nuts. Not only were these a staple in the diet of Native Americans, but bear, elk, deer, turkey, doves, squirrels, blue jays, mice, and passenger pigeons were just some of the native animals that depended on the American chestnut to get through the winter. And Castanea dentata was a food source to hundreds of species of insects, which in turn were food for birds.

It was a fungus, accidentally introduced with an Asian chestnut, that killed the American chestnut. In 1904 the epidemic was first spotted at the Bronx zoo. This blight would kill a tree by forming cankers on the trunk that blocked the flow of water between roots and leaves. The fungus spread from tree to tree at a rate of fifty miles a year. The lumber industry reacted with a panicked spasm of logging that likely contributed to the loss of the few trees which would have survived the epidemic.

Within forty years, up to four billion American chestnuts were dead. Both North America’s ecosystem and the logging industry were irrevocably altered. The one paltry good came out of the tragedy was the passing of the Plant Quarantine Act of 1912, which has slowed, but not stopped other plant pathogens from wrecking havoc on other vital American plants.

There are now so few Castanea dentata remaining, numbering in the hundreds, and they are so widely dispersed, that without human intervention they would surely be the last generation of American chestnut trees. But enter the American Chestnut Foundation. This organization has been working for decades to raise awareness, identify and protect surviving chestnut trees, and most importantly, breed a hybrid American chestnut that retains just enough Chinese ancestry to be resistant to the blight.

To this end, TACF has hand-pollinated many of the remaining trees, carefully tending the resulting generations in test plots up and down the East Coast. This brings us back to Idylbrook. Here, six hundred chestnut trees stand in the sun, looking innocently healthy and inconspicuous, as if they were just another common tree.

The eldest of Idylbrook’s chestnuts have matured, and have begun producing nuts. In an act that seems cruel at a glance, this year these trees were deliberately exposed to the blight. At some point in the future, the three or four of the healthiest trees out of a hundred will be chosen as breeding stock for the next generation. The rest will be removed from the gene-pool with a chainsaw.

Someday American chestnut will again be a major part of both the logging industry and the ecology, thanks to the long-term efforts of TACF. This tree is a vital part of America’s landscape, and at Idylbrook, history is in the making. I urge you to go for a visit before the next round of culling takes place, and then get involved. Become a member, donate, or volunteer: volunteers will be needed when the trees are cut down, and are needed on a continual basis for weeding, watering, and other maintenance work. More information can be found at acf.org, and at masschestnut.org, which is the local chapter of TACF.




2 comments:

hero爺 said...

Congratulation!

I knew your new baby from your another blog today.

I am waiting her to appear on this blog.

Michelle said...

Thank you Hero! :D You're right, I have neglected to post an announcement here! I should take care of that. . .