ERP113368 PRJEB30879 ena-STUDY-UNIVERSITY OF INNSBRUCK-20-01-2019-10:20:48:624-834 Fungal communities are diverse and dynamic in earliest soil developmental stages of a receding glacier We used amplicon sequencing and isolation of fungi from in-growth mesh bags to identify active fungi in three earliest stages of soil development (SSD) at a glacier forefield (0-3, 9-14, 18-25 years). Soil organic matter and nutrient concentrations were extremely low, but the fungal diversity was still high (220 OTUs / 138 cultivated OTUs). A clear successional trend was observed along SSDs, and species richness increased with time. Distinct changes in fungal community composition occurred with the advent of vascular plants. Fungal communities of recently de-glaciated soil are most distinctive, and rather similar to communities typical for cryoconite or ice. This indicates that melting water is an important inoculum for native soil. Moreover, communities growing in snow-free soil are significantly different from those growing in the snow-covered soil. Some fungal taxa, especially of the class Microbotryomycetes, showed a clear preference for winter and early SSD. Our results provide insight into new facets regarding the ecology of fungal taxa, e.g. by showing an alternative, saprobial lifestyle in snow-covered soil for representatives of biotrophic plant pathogens belonging to class Pucciniomycetes. The isolated fungi include a large proportion of unknown species, which can now be formally described and used for experimental approaches. Fungal communities in earliest ice-free soil We used amplicon sequencing and isolation of fungi from in-growth mesh bags to identify active fungi in three earliest stages of soil development (SSD) at a glacier forefield (0-3, 9-14, 18-25 years). Soil organic matter and nutrient concentrations were extremely low, but the fungal diversity was still high (220 OTUs / 138 cultivated OTUs). A clear successional trend was observed along SSDs, and species richness increased with time. Distinct changes in fungal community composition occurred with the advent of vascular plants. Fungal communities of recently de-glaciated soil are most distinctive, and rather similar to communities typical for cryoconite or ice. This indicates that melting water is an important inoculum for native soil. Moreover, communities growing in snow-free soil are significantly different from those growing in the snow-covered soil. Some fungal taxa, especially of the class Microbotryomycetes, showed a clear preference for winter and early SSD. Our results provide insight into new facets regarding the ecology of fungal taxa, e.g. by showing an alternative, saprobial lifestyle in snow-covered soil for representatives of biotrophic plant pathogens belonging to class Pucciniomycetes. The isolated fungi include a large proportion of unknown species, which can now be formally described and used for experimental approaches. ENA-FIRST-PUBLIC 2019-01-20 ENA-LAST-UPDATE 2019-01-20