Abstract Fire effects on ecosystems range from destruction of aboveground vegetation to direct and indirect effects on belowground microorganisms. Although variation in such effects is expected to be related to fire severity, another potentially important and poorly understood factor is the effects of fire seasonality on soil microorganisms. We carried out a large-scale field experiment examining the effects of spring versus autumn burns on the community composition of soil fungi in a typical Mediterranean woodland. Although the intensity and severity of our prescribed burns were largely consistent between the two burning seasons, we detected differential fire season effects on the composition of the soil fungal community, driven by changes in the saprotrophic fungal guild. The community composition of ectomycorrhizal fungi, assayed both in pine seedling bioassays and from soil sequencing, appeared to be resilient to the variation inflicted by seasonal fires. Since changes in the soil saprotrophic fungal community can directly influence carbon emission and decomposition rates, we suggest that regardless of their intensity and severity, seasonal fires may cause changes in ecosystem functioning. Declarations Funding This research was co-supported by the United States-Israel Binational Science Foundation (BSF Grant 2012081) and Tel-Hai College. Conflicts of interest/Competing interests We declare no conflicts of interest and that this material has not been submitted for publication elsewhere. Ethics approval Not applicable Consent to participate Not applicable Consent for publication Not applicable Availability of data and material Sequences were submitted to the National Center for Biotechnology Information Sequence Read Archive under accession numbers SRRXXX◻SRRXXX. Code availability Not applicable Authors’ contributions OO HS TB YO YC conceived and designed the experiment. SSL YA HM AT performed the experiment. SIG provided the pipeline scripts, and guidance in bioinformatics work and analyses. SLL OO HS wrote the paper and analyzed the data, and all authors contributed substantially to revisions.

High resilience of the mycorrhizal community to prescribed seasonal burnings in a Mediterranean woodland