Thursday, July 28, 2011

Tundra Fires Could Accelerate Climate Warming

In a study published in the July 28 issue of the journal Nature, UF ecologist Michelle Mack and a team of scientists including fellow UF ecologist Ted Schuur quantified the amount of soil-bound carbon released into the atmosphere in the 2007 Anaktuvuk River fire, which covered more than 400 square miles on the North Slope of Alaska's Brooks Range. The 2.1 million metric tons of carbon released in the fire -- roughly twice the amount of greenhouse gases put out by the city of Miami in a year -- is significant enough to suggest that Arctic fires could impact the global climate, said Mack, an associate professor of ecosystem ecology in UF's department of biology.

"The 2007 fire was the canary in the coal mine," Mack said. "In this wilderness, hundreds of miles away from the nearest city or source of pollution, we're seeing the effects of a warming atmosphere. It's a wake-up call that the Arctic carbon cycle could change rapidly, and we need to know what the consequences will be."

Smoke from the fire pumped greenhouse gases into the atmosphere, but that's just one part of a tundra fire's potential impact. The fire also consumed up to 30 percent of the insulating layer of organic matter that protects the permafrost beneath the tundra's shrub- and moss-covered landscape.

In a pine forest, fire would burn up leaf litter on the ground, but not the soil beneath. Because the Arctic tundra has a carbon-rich, peaty soil, however, the ground itself is combustible, and when the fire recedes, some of the soil is gone. In a double whammy, the vulnerable permafrost is not only more exposed, but also covered by blackened ground, which absorbs more of the sun's heat and could accelerate thawing.

"When the permafrost warms, microbes will begin to decompose that organic matter and could release even more carbon that's been stored in the permafrost for hundreds or thousands of years into the atmosphere," Mack said. "If that huge stock of carbon is released, it could increase atmospheric carbon dioxide drastically."

The study shows how isolated fires can have a widespread impact, said University of Alaska biology professor Terry Chapin. "When you think about the massive carbon stocks and massive area of tundra throughout the world, and its increasing vulnerability to fire as climate warms, it suggests that fire may become the dominant factor that governs the future carbon balance of this biome," Chapin said. "The paper by Michelle and her colleagues raises this possibility for the first time. It presents a very different perspective on the way in which climate change may affect this biome in the future."

Using radiocarbon dating, co-author Schuur and researchers from the University of Alaska Fairbanks, the Alaska Fire Service and Woods Hole Marine Biological Laboratory, found that carbon up to 50 years old had been burned in the 2007 fire.

Mack also developed a new method that can now be used by other tundra researchers to measure soil loss. By comparing the tussocks of sedge plants, which resprout after a fire, Mack was able to quantify soil heights and densities before and after the burn.
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Sunday, March 6, 2011

NASA scientist finds 'worm-like alien life form in meteorite'

Maybe this is what an alien really looks like - a worm-like bacteria.

NASA scientist Dr Richard Hoover claims to have found life form, which may explain how life on earth started and what's more, he challenges anyone to come forth and disprove his claim.

An astrobiologist with Nasa's Marshall Space Flight Center, Hoover explains that travelling to Antarctica, Siberia and Alaska he has studied an extremely rare form of meteorites - CI1 carbonaceous chondrites - of which only nine are known to exist on earth.

Under microscopes, these meteorites showed numerous different fossils of bacteria - some which are similar to ones on earth and others which are well, alien.

According to him, life on earth could have been planted by bacteria in an asteroid hitting the planet in its infancy.

In one case he found on a meteorite an organism similar in size and overall structure to the giant bacterium Titanospirillum velox, an organism found here on planet Earth.

"I interpret it as indicating that life is more broadly distributed than restricted strictly to the planet earth," the Daily Mail quoted him as telling Fox News.

"The exciting thing is that they [the bacteria] are in many cases recognisable and can be associated very closely with the generic species here on earth," he said.

He added, "There are some that are just very strange and don't look like anything that I've been able to identify, and I've shown them to many other experts that have also come up stumped."

In one of the remains, Hoover found no nitrogen.

"If someone can explain how it is possible to have a biological remain that has no nitrogen, or nitrogen below the detect ability limits that I have, in a time period as short as 150 years, then I would be very interested in hearing that," he said.

"I've talked with many scientists about this and no one has been able to explain."

Dr Rudy Schild, editor-in-chief of the journal Cosmology, said, "Given the controversial nature of his discovery, we have invited 100 experts and have issued a general invitation to over 5,000 scientists from the scientific community to review the paper and to offer their critical analysis."
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