A satellite-derived baseline of photosynthetic life across Antarctica

• Published in: Nature Geoscience
• Main Authors: Walshaw, Charlotte V., Gray, Andrew, Fretwell, Peter T., Convey, Peter, Davey, Matthew P., Johnson, Joanne S., Colesie, Claudia
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Research 2024
• Subjects: Antarc*; Antarctic; Antarctica; South Shetland Islands
• Online Access: http://nora.nerc.ac.uk/id/eprint/536526/; https://nora.nerc.ac.uk/id/eprint/536526/1/s41561-024-01492-4.pdf; https://www.nature.com/articles/s41561-024-01492-4

Terrestrial vegetation communities across Antarctica are characteristically sparse, presenting a challenge for mapping their occurrence using remote sensing at the continent scale. At present there is no continent-wide baseline record of Antarctic vegetation, and large-scale area estimates remain unquantified. With local vegetation distribution shifts now apparent and further predicted in response to environmental change across Antarctica, it is critical to establish a baseline to document these changes. Here we present a 10 m-resolution map of photosynthetic life in terrestrial and cryospheric habitats across the entire Antarctic continent, maritime archipelagos and islands south of 60° S. Using Sentinel-2 imagery (2017–2023) and spectral indices, we detected terrestrial green vegetation (vascular plants, bryophytes, green algae) and lichens across ice-free areas, and cryospheric green snow algae across coastal snowpacks. The detected vegetation occupies a total area of 44.2 km2, with over half contained in the South Shetland Islands, altogether contributing just 0.12% of the total ice-free area included in the analysis. Due to methodological constraints, dark-coloured lichens and cyanobacterial mats were excluded from the study. This vegetation map improves the geospatial data available for vegetation across Antarctica, and provides a tool for future conservation planning and large-scale biogeographic assessments.