First record of Poa cf. annua on Fildes Peninsula (King George Island), a major human-access node in Antarctica

César Capinha, Katarzyna J Chwedorzewska

Antarctic terrestrial ecosystems are highly species-poor and particularly vulnerable to biological invasions. Poa annua L. is the only non-native flowering plant known to have established a persistent, self-sustaining population in Antarctica, with confirmed occurrences on King George Island near the H. Arctowski Polish Antarctic Station and the Ecology Glacier forefield. Here we report a new occurrence of Poa cf. annua on Fildes Peninsula (King George Island), based on georeferenced field photographs of a single individual growing on disturbed ground near logistics infrastructure. This record lies well outside previously documented localities on the island, representing a geographically distinct occurrence in its south-western sector. Fildes Peninsula is one of the most intensively used human-access nodes in Antarctica, hosting multiple research stations and one of the continent’s few operational airstrips, and experiencing frequent and repeated human movement. The occurrence is therefore of particular biosecurity concern, as it may facilitate both local establishment and further dispersal. Given the species’ demonstrated capacity for seed-bank formation, persistence, and rapid spread under Antarctic conditions, rapid detection and immediate response are essential.