10 feb 2011

AMERICAN CHESTNUTS FOUNDATION

L'American Chestnut Foundation è stata fondata nel 1983 da un gruppo di studiosi di primo piano, che hanno riconosciuto il grave impatto che la scomparsa del castagno americano ha avuto per l'economia locale delle comunità rurali, e sulla ecologia delle foreste del paese.
Per saperne di più clikka QUI per acf.org e QUI per l'A.C.F. su twitter



The American Chestnut Foundation was founded in 1983 by a group of prominent plant scientists who recognized the severe impact the demise of the American chestnut tree imposed upon the local economy of rural communities, and upon the ecology of forests within the tree’s native range.


The American chestnut tree reigned over 200 million acres of eastern woodlands from Maine to Florida, and from the Piedmont west to the Ohio Valley, until succumbing to a lethal fungus infestation, known as the chestnut blight, during the first half of the 20th century. An estimated 4 billion American chestnuts, 1/4 of the hardwood tree population, grew within this range.


The American chestnut tree was an essential component of the entire eastern US ecosystem. A late-flowering, reliable, and productive tree, unaffected by seasonal frosts, it was the single most important food source for a wide variety of wildlife from bears to birds. Rural communities depended upon the annual nut harvest as a cash crop to feed livestock. The chestnut lumber industry was a major sector of rural economies. Chestnut wood is straight-grained and easily worked, lightweight and highly rot-resistant, making it ideal for fence posts, railroad ties, barn beams and home construction, as well as for fine furniture and musical instruments.

The blight, imported to the US on Asian chestnut trees, is a fungus dispersed via spores in the air, raindrops or animals. It is a wound pathogen, entering through a fresh injury in the tree's bark. It spreads into the bark and underlying vascular cambium and wood, killing these tissues as it advances. The flow of nutrients is eventually choked off to and from sections of the tree above the infection, killing them.

In 1989 TACF established the Wagner Research Farm, a breeding station in Meadowview, Virginia, to execute the backcross breeding program developed by Philip Rutter, Dr. David French and the late Dr. Charles Burnham, three of TACF’s founding scientists. The three of them wrote the first important paper about the breeding program (The citation is: Burnham, C.R., Rutter, P.A., and D.W. French. 1986. Breeding blight-resistant chestnuts. Plant Breeding Reviews 4:347-397). The goal was to breed blight resistance from the Chinese chestnut tree into the American chestnut tree, while maintaining the American chestnut’s characteristics.

TACF’s backcross breeding program took Chinese chestnut trees, naturally resistant to the blight, and crossed them with their American cousins, resulting in trees that were 50% American, 50% Chinese. These trees were then backcrossed to the American species, resulting in trees which were 75% American. The procedure was repeated to produce an American chestnut tree that retains no Chinese characteristics other than blight resistance. A second research farm in Meadowview was donated to TACF in 1995 by Mary Belle Price, in memory of her late husband Glenn C. Price, a strong supporter of TACF. A third Meadowview farm was purchased in 2002, and a fourth in 2006. Today, TACF’s Meadowview Research Farms have over 30,000 trees at various stages of breeding, planted on more than 160 acres of land.

Two independent reviews of TACF’s scientific mission, methods, and results, were conducted in 1999 and in 2006 by prominent scientists from around the world. They concluded that the vision of The American Chestnut Foundation to restore the American chestnut to its native habitat in the United States is being accomplished through the breeding program & other TACF activities, and that regional adaptability is key to a successful reintroduction of the American chestnut tree. The reviews were chaired by Dr. Ronald L. Phillips, Regents' Professor of Plant Genetics at the University of Minnesota and a member of the National Academy of Sciences.

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