Variation and drivers of soil fungal and functional groups among different forest types in warm temperate secondary forests

Soil fungal communities play a crucial role in maintaining and regulating ecosystem functions. The soil fungal structure of different plant communities in forests has been widely studied. However, the drivers of changes in soil fungal community dynamics in warm temperate secondary forests and the pathways influencing them remain to be explored. The Illumina high-throughput sequencing and FUNGuild platform were used to characterize the soil fungal diversity and community composition of six typical plant communities (JM, Juglans mandshurica; PD, Populus davidiana; QM, Quercus mongolica; MB, mixed broadleaf forest; MC, mixed conifer forest; PT, Pinus tabuliformis) in warm temperate secondary forests. The drivers of structural changes in dominant fungal taxa and functional groups were also explored. The pathways through which forest type, soil properties, altitude, climate, and plant diversity affected fungal community structure were further clarified. The results suggested that Ascomycota, Basidiomycota, and Zygomycota dominated the soil fungal communities in warm temperate secondary forests. Except for symbiotic fungi, there was no significant difference in soil fungal α-diversity among forest types. However, there were significant differences in total fungi and functional group community composition. The drivers of diversity and community composition of different soil fungal taxa in warm temperate secondary forests differed. In addition, the partial least squares path model indicated that the composition of soil fungal community in warm temperate secondary forests was directly influenced by forest type and was less dependent on soil properties. Collectively, our study highlights the importance of forest type, soil properties, and other factors (climate, altitude, plant diversity) in driving changes in soil fungal community structure.