Abstract ID: 3.10876 | Accepted as Talk | Talk/Oral | TBA | TBA

Mortierellaceae are cosmopolitan soil-inhabiting fungi that can be found in nearly all terrestrial habitat types and are therefore considered an essential part of the core soil microbiome. Many species from this family are known to endure harsh environments, including highly exposed and nutrient-depleted terrains like glacier forefields. The glaciers of the European Alps are highly impacted and threatened by climate change, leading to an increasingly accelerated retreat of the total glacial ice volume. This is especially drastic in calcareous glaciers, as they are usually characterized by lower altitudes. Recently deglaciated areas are highly interesting from an ecological perspective since they allow us to investigate the establishment of pioneer microbial communities and soil development in early stages. The focus of this study is the diversity of Mortierellaceae across four calcareous glacier forefields across the Alpine range (Switzerland: Grießen, Tsanfleuron, Italy: Marmolada, Austria: Dachstein). In total 20 sediments (five from each glacier forefield) from an altitude range of 2,250 -3,300 were analyzed, all derived from a calcite or dolomite bedrock. Every sampling location is deglaciated for only a maximum of 25 years with minimal to no plant succession and low soil organic material. The distribution and abundance of Mortierellaceae in the earliest stages of soil development were assessed based on an isolation-driven approach. Fungal pure cultures were obtained by direct-plating single soil grains. Fungal isolates were identified based on a combined approach (rDNA sequencing, phylogenetic analysis, and morphology). We could show that these calcareous glacier forefields harbor a rich and abundant diversity of Mortierellaceae. We detected 18 different Mortierellaceae taxa from these oligotrophic habitats with a large proportion of species typical for alpine environments: Mortierella triangularis was detected in each glacier forefield and, together with Mortierella lapis, can be considered widespread in high alpine habitats. We also isolated so far undescribed Mortierellaceae species from Dachstein and Marmolada. This proves that alpine glacier forefields are still understudied and raise further potential for future investigations. The ecological function and interactions of these fungi in alpine environments will be addressed in ongoing studies.