for National Geographic News
The highest microbial life on Earth appears to be in South America, where diverse ecosystems thrive at almost 19,850 feet (6,050 meters) above sea level.
Not counting those found living in clouds, the newfound creatures are the highest-altitude microbial communities known, said Steve Schmidt, a microbiologist at the University of Colorado at Boulder.
Schmidt and his team usually study the places where glaciers have retreated, to discover which microbes move in first to colonize the newly exposed soil.
Their work has implications for climate change and the search for life on other planets—on Mars, for example, the edges of ice fields are among the more likely places to search for microbial life.
But then, he said, "people in my lab became intrigued: Is there an altitudinal limit to life in soil?"
Like other "extreme" microbes living on volcanoes deep underwater, the new microbes were found around vents near the rim of the Socompa volcano, which sits on the border between Argentina and Chile in the Atacama Desert.
Most of the landscape that high up is barren, said Schmidt, whose most recent expedition to Socompa was funded in part by the National Geographic Society. (The National Geographic Society owns National Geographic News.)
But at the vents, steady emissions of water, carbon dioxide, and methane support 30-foot-wide (9-meter-wide) oases of moss and microbial communities.
"There's as much diversity of life as in garden soil," Schmidt said of the newly discovered zones. "Next to it, there's nothing."
The microbes are likely not active all the time, as soil temperatures may fluctuate in a single day from 5 to 140 degrees Fahrenheit (-15 to 60 degrees Celsius).
The harsh conditions make life tough for the field researchers too.
"There's very little water," Schmidt said. "You have to melt ice from the ice fields for water, or find it where it's trickling."
Findings published in the February issue of the journal Applied and Environmental Microbiology.
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