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Samuel B. Parsons Jr. (1844 – February 3, 1923) was an American landscape architect. He is remembered primarily for his accidental introduction of the fungus that led to the near extinction of the formerly widespread American chestnut tree.〔Jabr, Ferris. ("A New Generation of American Chestnut Trees May Redefine America's Forests." ) ''Scientific American'', March 1, 2014. Retrieved September 22, 2015.〕 ==American Chestnut Tree== Before the early 1900s one in every four hardwood trees in North America's eastern forests was an American chestnut. Together with oaks they predominated in 80 million hectares of forest from Maine to Florida and west to the Ohio Valley, reaching heights of up to 40 meters and growing two meters around the middle. Chestnuts sometimes piled so high on the forest floor that people would scoop them up with shovels. Both humans and a wide variety of animals relied on this abundant and easily gathered resource for food, particularly in winter.〔 Chestnut trees also had significant economic value. American carpenters preferred chestnut over other materials for making certain products. Lightweight, rot-resistant, straight-grained and easy to work with, chestnut wood was used to build houses, barns, telegraph poles, railroad ties, furniture and even musical instruments.〔 In 1876 Samuel B. Parsons imported Japanese chestnut trees which he then sold to customers in several states across the country. Some of these shipments concealed the pathogenic fungus Cryphonectria parasitica. The disease chokes the trees to death by wedging itself into their trunks and obstructing conduits for water and nutrients. Asian chestnut trees evolved a resistance but their North American relatives were highly susceptible to chestnut blight.〔 First discovered in New York State in 1904, the blight was soon spotted in New Jersey, Connecticut, Massachusetts and Pennsylvania. Within 50 years, C. parasitica killed nearly four billion chestnut trees. The species has been almost completely extirpated within its native range in one of the greatest ecological catastrophes in American history.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Samuel Parsons」の詳細全文を読む スポンサード リンク
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