Structure and spatial distribution of vegetation in maritime Antarctica: a case study of a protected area in Harmony Point, Nelson Island

Abstract

Harmony Point, located on Nelson Island in the South Shetland Islands, is one of the most ecologically significant Antarctic Specially Protected Areas (ASPA No. 133). Despite its recognized importance, the plant diversity and vegetation patterns of the region remain insufficiently documented. This study provides a detailed floristic and phytosociological survey and maps the spatial distribution of terrestrial plant communities across six sectors, including four beaches and two plateaus. Fieldwork was conducted during the austral summer of 2019 using standardized quadrat sampling and drone-based aerial imaging. A total of 75 species were identified, including one flowering plant (Deschampsia antarctica), 30 bryophytes (27 mosses and 3 liverworts), 42 lichens, and 2 terrestrial algae (Prasiola spp.). Seven distinct plant communities were recognized, shaped by environmental gradients, faunal influence (e.g., penguin and petrel colonies, fur and Weddell seals), and substrate availability. A novel zoned sociation involving Usnea aurantiacoatra, Himantormia lugubris, and Ochrolechia frigida is described here for the first time in Antarctica. Our results highlight the ecological relevance and floristic uniqueness of Harmony Point and reinforce the need for continued monitoring and conservation strategies in light of increasing climate change and human activity in the region.