Eventually, the hyphal threads of chestnut blight encircle the entire stem of the tree, strangling it in a process called girdling. These spores are spread by wind, water or other organisms to the next chestnut. Throughout this battle, the fungus produces little orange, spore-bearing structures (perithecia) on the canker. The fungus kills the cambium by producing oxalic acid and enzymatically digesting this layer in order to grow. These become more obvious when bark is sloughed off where cambium has been killed by the fungus, revealing the wood underneath. These outward symptoms of the struggle are called cankers.
As the fungus stretches its hyphae around this layer, the tree responds with thick growth to try to contain the pathogen. parasitica enters the tree through breaks in the bark of chestnuts, it grows in the living layer beneath it called the cambium. How Chestnut Blight Kills American Chestnuts Today, American chestnuts bear the scars of chestnut blight cankers. In this context, the damages done by chestnut blight are not just financial, but ecological and cultural.
This story ultimately places chestnuts as key to survival during hard times, and its moral is that chestnuts (and food generally) must be shared and planted widely. This dish introduced chestnuts into Iroquois mythology, where a boy named Hodadenon foolishly uses up the remaining stored chestnuts and must brave great danger to collect more. The tree’s abundant and edible nuts were easily storable provisions that could be stewed into porridge. The loss of the American chestnut is often framed as a loss for American industry, but Native Americans in the Eastern United States have valued this tree for centuries. The third entry describes the etiology of chestnut blight, which killed an estimated 4 billion American chestnuts in the 50 years following its introduction to New York in the early 1900’s.Īmerican Chestnut Foundation photo from the 19th century shows the monumental size of American chestnuts before chestnut blight spread throughout their natural range.
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The second, more practical, entry describes how these trees look to the modern observer: small and enfeebled by the unrelenting chestnut blight fungus that prevents these trees from reaching their full potential. The first is a memory of this tree’s historical stature, which was once so common and useful that it would make both cribs and caskets. In the Audubon Guide to North American Trees, the American chestnut has 3 descriptions. But, a virus and some genetic engineering may help us return this tree to the upper canopy of our forests. The legacy of the American chestnut ( Castanea dentata) is inextricably linked to its losing battle against a fungal pathogen, chestnut blight ( Cryphonectria parasitica).
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