CEMENT, BACTERIA LED TO OXYGEN SHORTAGE THAT STIFLED BIOSPHERE.Byline: Associated Press Biosphere biosphere, irregularly shaped envelope of the earth's air, water, and land encompassing the heights and depths at which living things exist. The biosphere is a closed and self-regulating system (see ecology), sustained by grand-scale cycles of energy and of 2, the costly experiment in creating a closed, self-sustaining ecosystem in Arizona, failed because the concrete walls ate up oxygen and left humans inside with barely enough to breathe. What was supposed to be a glass-enclosed copy of a pristine and smoothly functioning Earth evolved into a place choked with carbon dioxide carbon dioxide, chemical compound, CO2, a colorless, odorless, tasteless gas that is about one and one-half times as dense as air under ordinary conditions of temperature and pressure. and nitrogen, replete with uncontrollable weedy vines. Cockroaches cockroaches insects which may carry Salmonella spp. in their gut and play a part in the spread of the disease. , ants and katydids thrived. ``It was the boldest attempt ever'' to create a closed ecosystem, said David Tilman, a University of Minnesota (body, education) University of Minnesota - The home of Gopher. http://umn.edu/. Address: Minneapolis, Minnesota, USA. scientist, but it failed miserably. ``This suggests that there are areas of nature that are sufficiently great mysteries that we don't know Don't know (DK, DKed) "Don't know the trade." A Street expression used whenever one party lacks knowledge of a trade or receives conflicting instructions from the other party. how to manage them or make them better.'' Tilman and Joel E. Cohen Joel E. Cohen (b. February 10, 1944) is a mathematical biologist. He is currently Abby Rockefeller Mauzé Professor of Populations at the Rockefeller University and a professor of populations at the Earth Institute of Columbia University in New York City. of Rockefeller University and Columbia University in New York New York, state, United States New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of wrote an analysis of the Biosphere experiment for the journal Science, to be published today. Eight people were sealed into the Biosphere in September 1991, expecting to be isolated for two years and to raise their own food, breathe air recirculated by plants living with them and drink water cleaned by natural processes. But in less than 18 months, it was clear the system was terribly out of balance, Tilman said. Oxygen concentration dropped from 21 percent to 14 percent, about the same level present at 17,500 feet and barely enough to keep the crew functioning.It was learned later, said Tilman, that the humans were being suffocated by the Biosphere's cement walls. ``To grow food, they put in very rich soils, which contained a great amount of organic material that bacteria consumed,'' Tilman said. ``The bacteria used a lot of oxygen, dropping the oxygen levels. The bacteria released carbon dioxide, which became chemically bound up in the cement. That broke the cycle.'' With the carbon dioxide molecules trapped, the Biosphere's plants were unable to remove the molecules' carbon atoms and release their oxygen atoms for the projects' humans and other animals to breathe. This led eventually to the oxygen shortage. |
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