Plant physiologist Sharon Robinson has been monitoring plant health in Antarctica for more than 20 years and her findings are sobering. After a successful pilot project, she marked a series of Antarctic sites with tags on rocks in 2003 for on-going observation. She wanted to learn more about the endemic plants and how they survive in such extreme conditions.
Back then, the tags marked a series of lush, green moss beds. Some of mosses had survived for centuries, coping with long months of snow and ice every year.
When she returned to the sites in 2008, the moss had turned red, a sign of stress. After red comes grey, and, usually, death. Climate change was at work, snow and ice were retreating, plants were dying. “We were horrified,” Robinson remembers. “So we increased the frequency with which we were assessing them and went back three years later.”
The long-term monitoring project has since evolved from markers on rocks and still photography of the sites to GPS positioning systems and drone footage over larger areas. Robinson’s research has documented a rapid decline in plant health in Antarctica, with centuries-old mosses drying and even dying.
“An individual core of moss, as big as a finger and up to 14 cm long, could be up to 500 years old,” Robinson says. “We can date them by looking at radio-carbon down the stem. This drying out – it’s something that hasn’t happened to them in the last 500 years.”
With a doctorate in plant physiology from University College, London, and post-doctoral work at Duke University in the US and at ANU in Australia, by the 1990s Robinson had developed an interest in the reddish pigments used by many types of plants to survive changing conditions, like the red blush in certain cacti species and the red “sunscreen” in Antarctic mosses.
She accepted a position at Wollongong University in 1996 on the proviso she could use a grant from the Australian government to spend four months in Antarctica in that first year, researching endemic plant landscapes.
Now 60, a leading plant physiologist, a senior professor at the university and a member of the UN Environment Programme’s Environment Assessment Panel, Robinson has frequently returned to Antarctica over the years, using increasingly sophisticated technology to assess the plants in her sites and document their health.
“It’s almost like a desertification of Antarctica,” she says. “We had these amazing areas in the Australian Antarctic territory which are lush, green, beautiful sites. It’s really sad they’re going grey and they’re dying.”
She and her team-members now hope to return next year for the on-going monitoring of the sites after their trip last year was cancelled because of the Covid-19 pandemic. The possible installation of monitoring towers which can store and then transmit open access data year-round is also now on the agenda.
Meanwhile, Robinson is concerned global warming will foster conditions that allow alien species to take root in Antarctica with potentially disastrous consequences.
“We’re worried about seeds and spores,” she says, adding that until now, other types of plants have not generally been able to survive the extreme climate. “But as it warms up, all the endemic species are at risk both from climactic effects but also competition from invasive species.”