Wide divergence of fungal communities inhabiting rocks and soils in a hyper-arid Antarctic desert

Highly simplified microbial communities colonise rocks and soils of continental Antarctica ice-free deserts. These two habitats impose different selection pressures on organisms, yet the possible filtering effects on the diversity and composition of microbial communities have not hitherto been fully characterised. We hence compared fungal communities in rocks and soils in three localities of inner Victoria Land. We found low fungal diversity in both substrates, with a mean species richness of 28 across all samples, and significantly lower diversity in rocks than in soils. Rock and soil communities were strongly differentiated, with a multinomial species classification method identifying just three out of 328 taxa as generalists with no affinity for either substrate. Rocks were characterised by a higher abundance of lichen-forming fungi (typically Buellia, Carbonea, Pleopsidium, Lecanora, and Lecidea), possibly owing to the more protected environment and the porosity of rocks permitting photosynthetic activity. In contrast, soils were dominated by obligate yeasts (typically Naganishia and Meyerozyma), the abundances of which were correlated with edaphic factors, and the black yeast Cryomyces. Our study suggests that strong differences in selection pressures may account for the wide divergences of fungal communities in rocks and soils of inner Victoria Land. We tested the differential selective pressure of rock and soil habitats on fungal communities in Antarctic deserts. We found a strong differentiation of the communities in the two habitats characterised by different microclimatic conditions. Rocks were dominated by lichenized fungi, while soils by yeasts.image

Automated summary

This study compared fungal communities in rocks and soils in inner Victoria Land, Antarctica, and found significant differences in diversity between the two substrates. Lichen-forming fungi dominated rocks, possibly due to the more protected environment and the ability for photosynthetic activity. In contrast, yeasts were dominant in soils, with their abundance correlated to edaphic factors. The study suggests that strong selection pressures in different habitats contribute to the divergence of fungal communities.