الاثنين، 19 ديسمبر 2011

ScienceDaily: Top News

ScienceDaily: Top News


Climate change may bring big ecosystem shifts, NASA says

Posted: 18 Dec 2011 07:13 PM PST

By 2100, global climate change will modify plant communities covering almost half of Earth's land surface and will drive the conversion of nearly 40 percent of land-based ecosystems from one major ecological community type -- such as forest, grassland or tundra -- toward another, according to a new NASA and university computer modeling study.

Nitrogen from humans pollutes remote lakes for more than a century

Posted: 15 Dec 2011 11:16 AM PST

Nitrogen derived from human activities has polluted lakes throughout the Northern Hemisphere for more than a century and the fingerprint of these changes is evident even in remote lakes located thousands of miles from the nearest city, industrial area or farm. The findings are based on historical changes in the chemical composition of bottom deposits in lakes using an approach similar to aquatic archeology.

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