March 17, 2014
Moss Still Lives After 1500 Years Buried In Antarctic Ice
Brett Smith for redOrbit.com - Your Universe Online
British researchers who typically study polar moss samples because they provide indications of past climate conditions have found that Antarctic moss can survive trapped under ice for over 1,500 years.
While some plant material has been brought back to life after 20 years of being frozen, only microbes have been shown to be capable of thousand-year feats of revival; that is until now.
"These mosses were basically in a very long-term deep freeze," said study author Peter Convey of the British Antarctic Survey. "This timescale of survival and recovery is much, much longer than anything reported for them before."
The British scientist added that the findings have particular relevancy for Antarctic ecosystems and climate as mosses are main land producers in southern and northern polar regions. In the Arctic in particular, mosses are accountable for storing the majority of the fixed carbon. If mosses can get by in this way for such extended periods of time, then development of an ecosystem once the ice retreats wouldn't involve long-distance, transoceanic colonization events.
"What mosses do in the ecosystem is far more important than we would generally realise when we look at a moss on a wall here for instance,” Convey said. “Understanding what controls their growth and distribution, particularly in a fast-changing part of the world such as the Antarctic Peninsula region, is therefore of much wider significance."
In the study, which was published in the journal Current Biology, the team took cores of moss from deep in an icy moss bank in the Antarctic. The researchers sliced the frozen moss cores meticulously, keeping them clear of contaminants, and positioned them inside an incubator with a normal growth temperature and light level. After several weeks, the moss began to grow again. Using radioactive dating, the group found that the moss was at least 1,530 years old, and perhaps even older – as the moss would have been decades old when it was initially frozen.
"This experiment shows that multi-cellular organisms, plants in this case, can survive over far longer timescales than previously thought,” Convey said. “These mosses, a key part of the ecosystem, could survive century to millennial periods of ice advance, such as the Little Ice Age in Europe.”
"If they can survive in this way, then recolonization following an ice age, once the ice retreats, would be a lot easier than migrating trans-oceanic distances from warmer regions,” he added. “It also maintains diversity in an area that would otherwise be wiped clean of life by the ice advance.”
The researchers wrote in their conclusion that these polar mosses may be able to persist even longer than 1,500 years.
"The potential clearly exists for much longer survival—although viability between successive interglacials would require a period of at least tens of thousands of years," the researchers wrote. "Such a possibility provides an entirely new survival mechanism and a refugium for a major element of the polar terrestrial biota."
"Although it would be a big jump from the current finding, this does raise the possibility of complex life forms surviving even longer periods once encased in permafrost or ice,” Convey noted.