http://media.uow.edu.au/news/UOW115077.htmlClimate change stunting growth of century old Antarctic moss shoots
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A paper to appear in the January issue of Global Change Biology shows how the dominant plants in Antarctica have been affected by modern climate change. In a handful of coastal Antarctic ‘oases’ void of permanent ice cover, lush moss beds grow during the short summer season from December to February using melt water from streams and lakes. Up until now, measuring the seasonal growth rate of these plants has been extremely difficult and hence it was impossible to assess the impact of our changing climate.
This research, conducted by a team of environmental scientists from the University of Wollongong (UOW) and nuclear physicists from the Australian Nuclear Science and Technology Organisation (ANSTO), shows how the increased concentration of radiocarbon in the atmosphere resulting from nuclear weapons testing (mostly in the late 1950s and early 1960s, called the ‘the bomb spike’) can be used to accurately date the age of the moss shoots along their stems in a similar way to tree-rings.
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“Accurate dating along the moss stem allows us to determine the very slow growth rates of these mosses (ranging from 0.2 to 3.5 mm per year). Remarkably, these plants were already growing during the heroic age of Antarctic exploration. In terms of age these mosses are effectively the old growth forests of Antarctica -- in miniature,” Professor Robinson said.
Although increased temperature and precipitation in the polar regions due to climate change are predicted to increase growth rates, the scientists found that at some sites growth rates have declined since the 1980s. They suggest that this is likely due to moss beds drying out, which appears to be caused by increased wind speeds around Antarctica that are linked to the Antarctic ozone hole.
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