First extinction risk assessment of a bryophyte species in Antarctica

Assessing extinction risk is important for protecting species, as it is the starting point for conservation efforts. However, in Antarctica, none of the c. 116 species of bryophytes (the main terrestrial plant group) have been assessed. The global Aichi Biodiversity Targets stipulate that countries should have knowledge of the extinction risk of their entire flora. However, the Convention on Biological Diversity does not apply to the area of Antarctic Treaty governance, as Antarctica is not subject to national sovereignty. Recognizing the importance of understanding threats in this remote and ecologically sensitive region, we assessed the extinction risk of the moss Roaldia revoluta (Pylaisiaceae) in Antarctica. As far as we are aware, this is the first extinction risk assessment of a native plant on the Antarctic continent. Additionally, we provide a tool for estimating the number of bryophyte individuals. Our findings indicate R. revoluta should be categorized as Endangered. The species has not been documented in any Antarctic Specially Protected Area, suggesting both weakness in survey effort and a potential gap in conservation action. This study underscores the need for specific measures to mitigate the extinction risk faced by R. revoluta as an exemplar of threats facing Antarctic mosses, and emphasizes the importance of devoting resources to conserving Antarctic flora. This study will encourage further initiatives to investigate the risks facing Antarctic botanical diversity and strengthen support for safeguarding the continent’s biodiversity.