Effect of environmental parameters on biodiversity of the fungal component in lithic Antarctic communities.

A wide sampling of rocks, colonized by microbial epi-endolithic communities, was performed along an altitudinal gradient from sea level to 3600 m asl and sea distance from the coast to 100 km inland along the Victoria Land Coast, Antarctica. Seventy-two rock samples of different typology, representative of the entire survey, were selected and studied using denaturing gradient gel electrophoresis to compare variation in fungal diversity according to environmental conditions along this altitudinal and sea distance transect. Lichenized fungi were largely predominant in all the samples studied and the biodiversity was heavily influenced even by minimal local variations. The n-MDS analysis showed that altitude and sea distance affect fungal biodiversity, while sandstone allows the communities to maintain high biodiversity indices. The Pareto-Lorenz curves indicate that all the communities analyzed are highly adapted to extreme conditions but scarcely resilient, so any external perturbation may have irreversible effects on these fragile ecosystems.