Functional Ecology of Antarctic Flora

Antarctic mosses play foundational roles in terrestrial ecosystem processes, yet their functional ecology remains poorly understood. This study developed a novel functional trait-based framework for dominant moss species across glacier retreat gradients in the South Shetland Islands, addressing a critical gap in Antarctic bryophyte ecology. Nutrient- and water-related traits were measured for four moss species--Polytrichastrum alpinum, Bryum pseudotriquetrum, Sanionia uncinata, and Syntrichia saxicola--along with Deschampsia antarctica, across nine sites spanning early to late successional stages. Results revealed strong interspecific trait differentiation: P. alpinum exhibited conservative nutrient-use and rapid water-uptake strategies; S. uncinata and B. pseudotriquetrum displayed high water-holding capacities and nutrient content potentially linked to enhanced nutrient cycling and moisture buffering; S. saxicola showed traits favoring desiccation tolerance. Intraspecific trait plasticity was substantial for micronutrient traits but lower for water-related traits, suggesting species-specific capacities to respond to heterogeneous Antarctic environments. Hierarchical clustering identified four nutrient-related and five water-related functional groups, of which three and four, respectively, potentially aligned with ecologically meaningful strategies. Nutrient-related groups reflected potential contributions to carbon storage, nitrogen facilitation, and nutrient turnover; water-related groups indicated contrasting roles in water retention and desiccation tolerance. These findings provide the first empirical basis for linking Antarctic moss functional traits to ecosystem processes such as carbon accumulation, nutrient cycling, and microhabitat stabilization. As climate-driven greening accelerates in Antarctica, trait-based frameworks offer valuable tools for predicting the functional trajectories of expanding cryptogam-dominated ecosystems.