The evolutionary and environmental factors that shape fungal biogeography are incompletely understood. Here, we assemble a large dataset consisting of previously generated mycobiome data linked to specific geographical locations across the world. We use this dataset to describe the distribution of fungal taxa and to look for correlations with different environmental factors such as climate, soil and vegetation variables. Our meta-study identifies climate as an important driver of different aspects of fungal biogeography, including the global distribution of common fungi as well as the composition and diversity of fungal communities. In our analysis, fungal diversity is concentrated at high latitudes, in contrast with the opposite pattern previously shown for plants and other organisms. Mycorrhizal fungi appear to have narrower climatic tolerances than pathogenic fungi. We speculate that climate change could affect ecosystem functioning because of the narrow climatic tolerances of key fungal taxa.

Fungi are key players in vital ecosystem services, spanning carbon cycling, decomposition, symbiotic associations with cultivated and wild plants and pathogenicity. The high importance of fungi in ecosystem processes contrasts with the incompleteness of our understanding of the patterns of fungal biogeography and the environmental factors that drive those patterns. To reduce this gap of knowledge, we collected and validated data published on the composition of soil fungal communities in terrestrial environments including soil and plant-associated habitats and made them publicly accessible through a user interface at https://globalfungi.com. The GlobalFungi database contains over 600 million observations of fungal sequences across > 17 000 samples with geographical locations and additional metadata contained in 178 original studies with millions of unique nucleotide sequences (sequence variants) of the fungal internal transcribed spacers (ITS) 1 and 2 representing fungal species and genera. The study represents the most comprehensive atlas of global fungal distribution, and it is framed in such a way that third-party data addition is possible.

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Plant-soil feedback (PSF) is a fundamental mechanism explaining plant community composition. Two-phase experiments, i.e., conditioning and feedback, represent a common methodology to study PSF. The duration of the conditioning phase varies among studies and the PSF observed is often explained by its biotic component. Little is known about the temporal variation of PSF and its abiotic component. As early life stages are crucial for plant establishment, we grew Rorippa austriaca in soil conditioned over 2, 4, 6 or 8 weeks by a conspecific or a co-occurring species, Agrostis capillaris. For each conditioning duration, we analysed the soil chemical properties and the direction and intensity of intra- or inter-specific feedbacks. With increasing duration, the negative intra- and inter-specific feedbacks became stronger and weaker, respectively. The inter-specific feedback was more negative than the intra-specific feedback at 2 weeks and this reversed thereafter. The Mg content decreased with conditioning duration whatever the conditioning species was. With increasing duration, conditioning by R. austriaca strongly decreased pH, while A. capillaris did not affect pH. The K and P contents were not affected by the conditioning duration and were higher in R. austriaca soil than in A. capillaris soil. Our results suggest that not only conditioning species but also duration of conditioning phase may affect the magnitude of PSF. The changes in soil chemical properties linked to the conditioning species or the conditioning phase duration may drive the feedbacks by affecting plant growth directly or via the interacting microbial communities.