Antarctica’s icy white facade gives the continent an image as a still and barren landscape. However, a recent study has reinforced an important contrast: The mostly monochrome backdrop hosts a vibrant community of hardy and colorful vegetation.
Scientists have now mapped out vegetation across the whole of coastal Antarctica. Patches of vascular plants, bryophytes, lichens, and algae dot ice-free areas, and green snow algae cover sections of coastal snowpack.
The vegetation spans an area of just 44 square kilometers (17 square miles)—a small fraction of Antarctica’s 14.2 million square kilometers (5.5 million square miles). “It is about the size of Manhattan Island on a continent larger than Australia,” said Claudia Colesie, a polar ecologist at the University of Edinburgh and a member of the research team.
The group created the continent-wide map using data from the European Space Agency’s Sentinel-2 mission. Instruments aboard the mission’s pair of satellites detect light reflected from Earth’s surface. The color of the light helped the scientists distinguish vegetation from rock and snow. Field observations helped to ground truth the imagery.
Other satellites with coarser imaging capabilities have not been able to detect Antarctica’s patchy, sparse vegetation accurately. Previous research was limited to small-scale maps for monitoring, making it difficult to tell whether vegetation changes at a particular site were significant or minor.
Sentinel-2 imagery has a resolution of 10 meters (33 feet), allowing the satellites to detect these smaller-scale features throughout the continent. The new map, which used data from 2017 to 2023, provides a broader perspective that will allow scientists to compare future observations with the complete picture of vegetation distribution and more accurately assess changes.
The study and map were published in a paper in Nature Geoscience.
A Base Map
“This project made me realize how important this map is going to be for conservation and in identifying vegetation in key areas, which might not be currently protected,” said Charlotte Walshaw, who is pursuing a Ph.D. in remote sensing at the University of Edinburgh and the study’s first author.
As a result of climate change, much of Antarctica’s ice-covered areas are melting, exposing more land. “There is clear evidence from local-scale studies that populations of Antarctica’s two flowering plants and some mosses have expanded rapidly in recent decades,” said Peter Convey, a polar ecologist and biogeographer at the British Antarctic Survey and a study coauthor. The new map could be used for vegetation monitoring to document changes throughout the Antarctic.
“The mapping presented in this paper is very helpful for understanding the impact of global change on Antarctic plants and will aid our efforts to protect them.”
“Given the lack of large-scale mapping and data on plant distribution and status in Antarctica, there are significant controversies and knowledge gaps regarding the response trends of Antarctic ecosystems to global change,” wrote Wenjin Wu in an email. Wu is a remote sensing scientist at the Chinese Academy of Sciences who was not involved in the study. “The mapping presented in this paper is very helpful for understanding the impact of global change on Antarctic plants and will aid our efforts to protect them.”
By merging the new map with data from prior studies and utilizing more satellite imagery, researchers may be able to construct forecasts for biodiversity changes in Antarctica, according to Colesie and Walshaw.
—Larissa G. Capella (@CapellaLarissa), Science Writer
