Species on the move in Antarctic terrestrial communities

Sharon A. Robinson (1,2), Melinda J. Waterman (1,3), Diana H. King (1,4), Johanna D. Turnbull (1,5), Michael B. Ashcroft (1,6) Jessica Bramley-Alves (1,7), Ellen Ryan-Colton (1,8), Jane Wasley (9)

¹Centre for Sustainable Ecosystem Solutions, Faculty of Science, Medicine and Health, University of Wollongong, NSW 2522, Australia,

²sharonr@uow.edu.au, @Antarcticmoss,

³melindaw@uow.edu.au ,

⁴dhk442@uowmail.edu.au,

⁵johannat@uow.edu.au,

⁶ashcroft@uow.edu.au,

⁷jba605@gmail.com,

⁸ellen.ryan.colton@gmail.com

⁹Australian Antarctic Division, Department of Environment, Kingston, Tasmania, 7050, Australia, Jane.Wasley@aad.gov.au

Antarctica has experienced major changes in temperature, wind speed and stratospheric ozone levels over the last 50 years. Whilst West Antarctica and the peninsula have shown rapid warming and consequent ecosystem change, East 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 have shown that radiocarbon signals preserved along shoots of the dominant Antarctic moss flora can be used 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 the recent climate change. This work has revealed evidence of a drying trend in several of the extensive moss beds in the Windmill Islands region of East Antarctica. Long-term monitoring of vegetation communities along moisture gradients at two sites commenced in 2003 using three complementary sampling regimes; turf water content, digitally determined broad-scale percent cover of vegetation and finer scale relative abundance of species. These methods indicate that species are on the move even in those regions were it is hard to detect evidence of climate change. These findings highlight the importance of developing a robust Antarctic terrestrial and near-shore observing network and considering the efficacy of the current protected areas across the Antarctic continent to adequately protect biodiversity.