The french molecular inventory of soil fungi

National audience

English. The fungal kingdom has been diversifying for more than 800 million years and has colonized a large number of habitats on Earth. With 2 to 12 million estimated species mostly found in soils, this heterotrophic kingdom is probably the second most diverse one among Eukaryota after animals. Fungi are major ecological players that support various ecosystem functions across trophic levels. Based on a unique dataset in the world (2,200 soil samples) from the French Soil Quality Monitoring Network and using a metabarcoding approach (18S rDNA marker), we described the abundance, diversity, and composition of soil fungal communities on a large scale and identify the environmental filters (e.g., soil parameters, land uses, climate types) which condition these distributions. We also addressed more precisely the distribution of major fungal taxa (phylum and class level) present in French soils, allowing a better understanding of their ecology, in terms of sensitivity to certain environmental conditions and involvement in the major functions and services provided by soils. We also identified a complex mosaic of 10 distinct terrestrial habitats, based on soil type, land uses and climate type. All these information have been synthetized in the French Atlas of Soil Fungi (2024, Biotope editions), a unique work both in terms of the subject matter and original representations, allowing us to understand the mysterious and incredible world of this invisible kingdom. Moreover, this Atlas concludes with operational demonstrations on fungi as bioindicators of soil quality to assess the impact and sustainability of certain agricultural or urban practices. Release scheduled during 2024.