Thursday, February 9, 2012

Climate change affecting Antarctica faster than previously thought

Xinhua: Climate change is affecting the world's last great unspoiled wilderness of the Antarctic faster than previously thought, according to a New Zealand-led international team of researchers. The scientists, led by Professor Craig Cary, of the University of Waikato, have been studying ecosystems in the continent's Dry Valleys and found that microbial communities in the soil undergo rapid and lasting changes in response to environmental conditions.

"We used to think that changes in microbial change took place slowly over centuries, but the research we've been doing indicates that the bacteria living in the soil are inherently sensitive to climate variability," said Cary in a statement. "Minor temperature variations could lead to cascading changes in hydrology and biogeochemical cycling and could dramatically affect ecosystem function."

The scientists measured the rate at which observed biological changes occurred beneath a seal carcass and at a nearby control site. They found that under the carcass the soil environment changed by stabilizing temperatures, elevating relative humidity and reducing ultraviolet exposure.

They then determined the speed of the changes by transferring a 250-year-old carcass to an untouched site and used community DNA fingerprinting and new sequencing techniques to track the changes in microbial composition and structure. It took only two years for major changes to occur during the five-year study.

Cary said polar systems were particularly susceptible to climate change and the study would provide a foundation for future observations on the fate of life in the extreme environments....

A mummified seal carcass in the McMurdo Dry Valleys, Antarctica, shot by Mila Zinkova, Wikimedia Commons, under the Creative Commons Attribution ShareAlike 3.0 License

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