Climate Change Stunting Growth of 100-Year-Old Moss Shoots in Antarctica
28.11.2011 - Flora & Fauna, Antarctic
In a paper to be published in January in the journal Global Change Biology, a team of scientists from the University of Wollongong (UOW) in conjunction with nuclear scientists from the Australian Nuclear Science and Technology Organization (ANSTO) suggests that mosses, the dominant plants in Antarctica, have been affected by current climate change. Until now, measuring the growth of the moss beds that grow between December and February in ice-free Antarctic coastal areas was almost impossible, making it difficult to assess how the changing climate is affecting the plants.
In this study, the scientists used the increased concentration of radiocarbon in the atmosphere from nuclear weapons testing in the late 1950s and early 1960s to date the age of the moss shoots along their stems in a similar to how one dates using tree-rings. This accurate dating technique allowed the researchers to determine the extremely slow growth rates of these mosses (ranging from 0.2 to 3.5 mm per year). With radiocarbon signatures appearing in the top 15 mm of 50 mm-long shoots, this indicates that the mosses may be more than 100 years old.
While rising temperatures and increasing precipitation in the Polar Regions are likely to spur growth rates, the scientists found that moss growth rates in some areas have declined since the 1980s. The team believes that the main reason is that moss beds are drying out, which could be caused by increased wind speeds resulting from the ozone hole over Antarctica.
