Environmental Gradients Shape Fungal Diversity and Functional Traits in Arctic Biocrusts

Arctic biological soil crusts (biocrusts) are known to host diverse fungal communities that facilitate nutrient cycling and soil stabilisation in these harsh environments. In this study, the diversity and composition of fungi were assessed across elevation and spatial gradients in biocrusts from Kongsfjorden (Svalbard) using metagenomic sequencing. Within the observed fungal phyla, Ascomycota was dominant across all sites, with Basidiomycota and Rozellomycota also exhibiting high abundances. Furthermore, saprotrophic fungi were most abundant, followed by mycorrhizal and parasitic guilds. Lichen-associated fungi were also detected across the samples, although their read counts were substantially lower. Additionally, the fungal genus richness and guild composition exhibited no significant variation between elevations, but location within the fjord strongly shaped community structure.