Traces from old N-tests found in Antarctic moss
Sydney: Nuclear weapons, tested 50 years ago, have left their imprint on living moss shoots in the Antarctica.
These imprints, known as atmospheric radiocarbon 14C or bomb spikes, have provided scientists with evidence of significant climate change in East Antarctica.
The discovery was made by researchers from University of Wollongong and the Australian Nuclear Science and Technology Organisation (ANSTO).
Led by Sharon Robinson, professor at Wollongong, the team collected samples of four moss species from five sites in East Antarctica and analysed them for 14C content, reports the journal Global Change Biology.
Spikes of 14C detected in the samples were correlated with records of annual atmospheric 14C and 14C tree-ring data, which then allowed the team to calculate the age of the moss samples, according to an ANSTO statement.
"Mosses grow in an incremental fashion from the shoot tip and retain a record of atmospheric carbon encountered over their photosynthetic lifespan along the length of their shoots," Robinson said.
"In some of our moss species, the peak of the radiocarbon bomb spike was found just 15 mm from the top of the 50 mm shoot, suggesting that these plants may be more than 100 years old."
"Our results point to a profound influence of recent climate change on the Antarctic flora," Robinson said.