Fungal diversity and functionality is driven by soil texture in Taylor Valley, Antarctica

McMurdo Dry Valleys surface is mainly constituted by unconsolidated permafrost. Despite the combination of cold and dry conditions, transiently wetted soils close to lake edges are hotspot of intense biological activity, that can support the surrounding soil ecosystems in a such extreme environment. These latter soils host simple microbial communities that allow the easy characterization of the parameters determining microbial establishment and diversification. Soil samples were collected close to three different glacial lakes (Lake Fryxell, Lake Hoare and Lake Joyce) located along a longitudinal gradient from lower to upper Taylor Valley. Fungal diversity and functionality of sampled soils was studied through ITS1 metabarcoding sequencing. The correlation between the parameters describing fungal diversity (i.e. total richness, the relative richness of dominant taxonomic and functional groups and community composition) and the edaphic physicochemical parameters (i.e. pH, moisture, C, N, P, Na+, K+, Mg2+ and Ca2+, cation exchange capacity, and soil granulometry) was checked. The fungal communities showed low diversity (48 ± 32 OTUs per sample) and resulted highly diversified, even in different sites of the same locality. The main parameters affecting the diversity and composition of fungal communities were soil texture, in turn influencing the retention of water and nutrients, and physicochemical properties. This is of particular concern for the survival of these communities, given the expected environmental changes due to global warming.