Researchers have shown that after being frozen over 1,500 years in Antarctic ice, moss can come back to life and continue to grow. For the first time, this vital part of the polar ecosystem has demonstrated its ability to survive after being frozen for over such an incredibly long time. Well, to be perfectly fair, it's probably not the first time it's done this - it's just the first time we actually studied it.
The team included researchers from the British Antarctic Survey and Reading University who reported moss regeneration after at least 1,530 years frozen in permafrost. This is the first study to study this kind of long-term survivability in any plant - similar timescales have only been previously reported in bacteria.
As I said, mosses are crucially important to the biology of both polar regions. They are the dominant plants over large areas and are a major storer of fixed carbon, and across the world, there are approximately 12,000 species of moss. It has been previously shown that they can survive for a few decades in these extreme, arctic environments, but their potential to survive much longer timescales remained unstudied.
This discovery potentially has massive implications. Co-author Professor Peter Convey from the British Antarctic Survey explains:
"What mosses do in the ecosystem is far more important than we would generally realize when we look at a moss on a wall here for instance. 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."
The team drilled cores in the polar ice and took samples of moss from deep ice. To maximize the chances of regeneration, they picked a moss that was already several decades old when it was frozen. After they found a satisfying sample, they sliced the frozen moss cores very carefully, keeping them free from contamination, and placed them in an incubator at a normal growth temperature and light level. It only took a few weeks for the moss to start growing again. Using carbon dating, the team identified the moss to be at least 1,530 years of age, and possibly even older, at the depth where the new growth was seen.
According to Professor Convey:
"This experiment shows that multi-cellular organisms, plants in this case, can survive over far longer timescales than previously thought. 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 recolonisation following an ice age, once the ice retreats, would be a lot easier than migrating trans-oceanic distances from warmer regions. It also maintains diversity in an area that would otherwise be wiped clean of life by the ice advance."
Well, this last part may be a bit of a jump, as Convey himself admits it:
"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."
This is, indeed, truly remarkable. The fact that a plant can survive after being frozen for 1500 years simply blows my mind.
- Esme Roads, Royce E. Longton, Peter Convey. Millennial timescale regeneration in a moss from Antarctica ,. Current Biology, Volume 24, Issue 6, 17 March 2014, Pages R222-R223 DOI: 10.1016/j.cub.2014.01.053