New research, reported in the Proceedings of the National Academy of Sciences, suggests that the steam and heat from volcanoes may have allowed many plant and animal species to survive past Ice Ages.
Mount Erebus, the second highest volcano in Antarctica and the southernmost active volcano on our planet. Image credit: Steven Chown / Monash University.
Researchers studied tens of thousands of records of Antarctic species and found there are more species close to volcanoes, and fewer further away.
“The closer you get to volcanoes, the more species you find. This pattern supports our hypothesis that species have been expanding their ranges and gradually moving out from volcanic areas since the last Ice Age,” explained study co-author Dr Aleks Terauds from the Australian Antarctic Division.
Antarctica has about 16 volcanoes which have been active since the last Ice Age 20,000 years ago.
The scientists examined diversity patterns of mosses, lichens and bugs which are still common in Antarctica today.
“Around 60 per cent of Antarctic invertebrate species are found nowhere else in the world,” said co-author Prof Peter Convey from the British Antarctic Survey.
“They have clearly not arrived on the continent recently, but must have been there for millions of years. How they survived past Ice Ages – the most recent of which ended less than 20,000 years ago – has long puzzled scientists.”
“Volcanic steam can melt large ice caves under the glaciers, and it can be tens of degrees warmer in there than outside. Caves and warm steam fields would have been great places for species to hang out during Ice Ages,” said lead author Dr Ceridwen Fraser from the Australian National University.
“We can learn a lot from looking at the impacts of past climate change as we try to deal with the accelerated change that humans are now causing.”
While the study was based on Antarctica, the findings help scientists understand how species survived past Ice Ages in other icy regions, including in periods when it is thought there was little or no ice-free land on the planet.
Also the results could help guide conservation efforts in Antarctica. “Knowing where the ‘hotspots’ of diversity are will help us to protect them as human-induced environmental changes continue to affect Antarctica,” said senior author Prof Steven Chown from Monash University.
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Fraser CI et al. Geothermal activity helps life survive glacial cycles. PNAS, published online March 10, 2014; doi: 10.1073/pnas.1321437111
