A few Ascomycota taxa dominate soil fungal communities worldwide

Despite having key functions in terrestrial ecosystems, information on the dominant soil fungi and their ecological preferences at the global scale is lacking. To fill this knowledge gap, we surveyed 235 soils from across the globe. Our findings indicate that 83 phylotypes (<0.1% of the retrieved fungi), mostly belonging to wind dispersed, generalist Ascomycota, dominate soils globally. We identify patterns and ecological drivers of dominant soil fungal taxa occurrence, and present a map of their distribution in soils worldwide. Whole-genome comparisons with less dominant, generalist fungi point at a significantly higher number of genes related to stress-tolerance and resource uptake in the dominant fungi, suggesting that they might be better in colonising a wide range of environments. Our findings constitute a major advance in our understanding of the ecology of fungi, and have implications for the development of strategies to preserve them and the ecosystem functions they provide.

E.E. and B.K.S. were supported by the CRC-CARE project 4.2.06–16/17; B.K.S. was also supported by the Australian Research Council (DP 170104634 and DP190103714). M.D.-B. acknowledges support from the Marie Sklodowska-Curie Actions of the Horizon 2020 Framework Programme H2020-MSCA-IF-2016 under REA grant agreement no. 702057; J.P. would like to acknowledge the Australian Research Council for research funding (DE150100408). The work of F.T.M. and the global drylands database were supported by the European Research Council (ERC Grant Agreements 242658 [BIOCOM] and 647038 [BIODESERT]) and by the Spanish Ministry of Economy and Competitiveness (BIOMOD project, ref. CGL2013–44661-R). R.D.B. was supported by the UK Department of Environment, Food and Rural Affairs (DEFRA) project number BD5003 and a BBSRC International Exchange Grant (BB/L026406/1).