Hardy Antarctic moss.
Ah, Antarctica. A vast expanse of ice, interrupted by mountains, ice… and more ice (with the occasional penguin). But in the East of the continent and on the Windmill Islands near Australia’s Casey research station, bare ground can actually be seen during summer months. Here Antarctica’s endemic plants dwell: lichens, terrestrial algae, and mosses. These smatterings of bryophytes are amongst the hardiest flora in the world, providing a home for a variety of minute life. They survive being covered in snow most of the year, only growing briefly during the summer months, watered by snowmelt. Except for in-person observations made over the last two decades, little definitive was known about these oases of diversity, like their age or how they might respond to changes in climate.
But now, some of the moss’s secrets are out. A recent study in the journal Global Change Biology found that some of these plants must be more than a century old, and a few may even be thousands of years old, said researcher and study author Sharon Robinson via email. On average these mosses grow at the glacial speed of 1 millimeter per year—and some of the turfs are meters thick. That means many of these unassuming mossy carpets were there when humans first made it to the continent a century ago—and likely well before. “These mosses are effectively the old growth forests of Antarctica—in miniature,” Robinson said.
Workers taking a biological census have just completed their first 10-year count of marine organisms living near the North and South poles, and they found more inhabitants than anyone expected. They found some 13,000 kinds of animals living at one pole or the other, or, in a surprising number of cases, at both” [Science News]. The Census of Marine Life began the project in 2000 and involves thousands of researchers worldwide, hundreds of whom participated in more than a dozen expeditions to both poles.
The complete report will be issued next year, but a summary of findings has just been released and reports about 7,500 species in the Antarctic region and 5,500 in the Arctic. The poles were found to share 235 species, although further DNA testing is being conducted to confirm that they are identical, and that they do not just look alike. Among the “bi-polar” organisms are worms, crustaceans, and birds, as well as great whales, which after centuries of whaling … had been thought to remain only in the North Pacific and along the west coast of North America [Environment News Service]. Some of the bi-polar species identified, such as two snail-like species that have become almost as filmy as jellyfish and flutter through seawater instead of crawling, are not known from anywhere in between the poles [Science News].
Several new studies of ice loss at the earth’s poles paint a distressing picture of global warming‘s impact on those fragile ecosystems, and one study warns that changes in the Arctic climate can have a large impact on the rest of the world. In the first study, researchers determined that more than 2 trillion tons of landlocked ice in Greenland, Alaska, and Antarctica have melted since 2003, a melting trend that researchers expect to continue. Using new satellite technology that measures changes in mass in mountain glaciers and ice sheets, NASA geophysicist Scott Luthcke concluded that the losses amounted to enough water to fill the Chesapeake Bay 21 times. “The ice tells us in a very real way how the climate is changing,” said Luthcke [CNN].
Melting of land ice, unlike sea ice, increases sea levels very slightly. Between Greenland, Antarctica and Alaska, melting land ice has raised global sea levels about one-fifth of an inch in the past five years, Luthcke said. Sea levels also rise from water expanding as it warms [AP]. The amount by which sea levels will rise as a result of global warming is still uncertain. The UN’s Intergovernmental Panel on Climate Change gives an official estimate of a seven-inch to two-foot rise by 2100, but researchers say conditions at the poles are changing too quickly for confident predictions.