Plants in Antarctica are growing faster as a result of global warming, which could represent a tipping point in the region's changing ecosystem. Scientists have already observed increased plant growth as a result of climate change in the northern hemisphere, but this is the first time this has been observed in the southern Antarctic.
Findings of Study:
From 2009 to 2019, Nicoletta Cannone of the University of Insubria in Italy and her colleagues tracked the growth of the Antarctic's only two native flowering plants, Deschampsia Antarctica and Colobanthus quitensis, at a number of sites on Signy Island.
The researchers then compared their findings to surveys conducted over the previous 50 years and discovered that not only had the plants become more densely populated at the sites, but they had also grown faster each year as the climate warmed.
The Deschampsia grew as much in ten years as it did in fifty years from 1960 to 2009, while the Colobanthus grew five times as much.
"The most novel feature of this is not the idea that something is growing faster," says British Antarctic Survey team member Peter Convey, "but that the growth appears to be accelerating." "It's that we believe we're approaching something akin to a tipping point or a step-change."
According to Matthew Davey of the Scottish Association for Marine Science in Oban, UK, "accelerated expansion is now clearly visible in the region."
"This study provides us with the first comprehensive data set showing how quickly and densely the plant community can expand," he says. Though other factors, such as a declining fur seal population, may have aided plant growth, the link to a warming climate is clear, according to Cannone.
Temperature rises may also allow invasive species to colonize and outgrow native plants, as has already been observed in Alpine regions, potentially destabilizing local ecosystems and biodiversity. "If we extrapolate what we saw on Signy Island to other sites in Antarctica, we can see a similar process," Cannone says. "This implies that the Antarctic landscape and biodiversity may change quickly."
