HALF OF EARTH�S PLANT SPECIES THREATENED
Recent work published in the journal Science by two U.S. botanists, Peter Jorgensen of the Missouri Botanical Garden and Nigel Pitman of Duke University, has estimated that up to 50 percent of the plant species on the planet may be facing imminent extinction. Previous estimates by the World Conservation Union had placed the numbers at between 12 and 13 percent. While that number is frightening, the numbers pointed to by this new study are even scarier. The researchers state that we are on the verge of a catastrophic extinction crisis. The revised estimate is due because the figures used by the World Conservation Union to calculate plant species at risk took into account only those species growing in North America, Europe, Australia, and southern Africa. No data was available from developing countries in tropical regions, where most plant species grow. The researchers have extrapolated extinction trends found in temperate areas to the tropics. One key issue of the problem is that many plant species only grow in very small geographic areas and are therefore subject to extreme pressure from local stresses or destruction of their respective environments. Many such isolated species have yet to be discovered and catalogued by science.
current science news posted by ted at 11/04/2002 12:23:00 PM
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