Silvicultural practices and interannual variation shape ectomycorrhizal fungal diversity and community composition in an oak-hornbeam forest in northern Hungary

Ectomycorrhizal (ECM) fungi are well-known for their crucial roles in forest health and productivity, yet their responses to various forest management practices are understudied, particularly in oak-dominated forests. The purpose of this study was to better understand the effects of silvicultural treatments on the diversity and community composition of ECM fungi in an oak-hornbeam forest in northern Hungary. We analyzed ITS2 rDNA metabarcoding data of soil-borne fungi to compare richness and community composition of ECM fungi among forest treatment types (clear-cutting, gap-cutting, preparation-cutting, tree retention in clear-cut areas, and control) and between sampling years (2020 and 2021). We found 268 ECM fungal genotypes, with the most diverse phylogenetic clades being /russula-lactarius (52), /tomentella-thelephora (47), /inocybe (40), /sebacina (27), and /cortinarius (20). We found significant compositional difference of ECM fungi among silvicultural treatments in both years, with some variations in richness. There were also small, but still significant compositional differences between the two years. Treatment effect was partly explained by altered environmental variables, such as relative humidity and soil temperature. These results highlight the importance of forest structure and the abiotic environment in driving community dynamics of plant-symbiotic fungi, with potential implications for forest health and productivity.