The Antarctic has experienced major changes in temperature, wind speed and stratospheric ozone levels during the last 50 years. However, until recently continental Antarctica appeared to be little impacted by climate warming, thus biological changes were predicted to be relatively slow. Detecting the biological effects of Antarctic climate change has been hindered by the paucity of long-term data sets, particularly for organisms that have been exposed to these changes throughout their lives. We show that radiocarbon signals are preserved along shoots of the dominant Antarctic moss flora and use these to determine accurate growth rates over a period of several decades, allowing us to explore the influence of environmental variables on growth and providing a dramatic demonstration of the effects of climate change. We have generated detailed 50-year growth records for Ceratodon purpureus and three other Antarctic moss species using the 1960s radiocarbon bomb spike. Our growth rate and stable carbon isotope (δ¹³C) data show that C. purpureus’ growth rates are correlated with key climatic variables, and furthermore that the observed effects of climate variation on growth are mediated through changes in water availability. Our results indicate the timing and balance between warming, high-wind speeds and elevated UV fluxes may determine the fate of these mosses and the associated communities that form oases of Antarctic biodiversity.

Item Type:	Refereed Article
Keywords:	Antarctic moss, climate change, growth rate, ozone depletion, radiocarbon, stable isotopes, Vestfold Hills, water availability, Windmill Islands
Research Division:	Environmental Sciences
Research Group:	Climate change impacts and adaptation
Research Field:	Ecological impacts of climate change and ecological adaptation
Objective Division:	Environmental Policy, Climate Change and Natural Hazards
Objective Group:	Understanding climate change
Objective Field:	Effects of climate change on Antarctic and sub-Antarctic environments (excl. social impacts)
UTAS Author:	Clarke, LJ (Dr Laurence Clarke)
ID Code:	104030
Year Published:	2012
Web of Science® Times Cited:	46
Deposited By:	CRC-Antarctic Climate & Ecosystems
Deposited On:	2015-11-01
Last Modified:	2017-10-31
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