Abstract:

Fire frequently causes strong disturbance in forests. Belowground fungi are sensitive to forest fire disturbance and can affect vegetation restoration. Our objective was to investigate the responses of belowground fungi under two tree species to forest fire in a mixed forest in Yunnan Plateau. Samples from three ‘sample sites’ (roots, rhizosphere soil and bulk soil) were collected from two plant species, Pinus yunnanensis and Eucalyptus citriodora, and were analyzed for fungal diversity and community composition. Fungi were identified using high-throughput sequencing. Shannon index and principal coordinate analysis were used for diversity and network analysis. LEfSe and FUNGuild were used to analyze the community composition, trophic mode and guild. Alpha diversity in bulk soil was higher than that in rhizosphere soil and roots, while the community composition was significantly different among the three sample sites. Fungal network complexity of E. citriodora was higher than that of P. yunnanensis. The relative abundance of Mucoromycota in the three sample sites was higher for P. yunnanensis than E. citriodora. Most of the top 10 dominant genera of the two plant species were saprotrophic fungi. In the comparison of biomarker, ectomycorrhizal fungi dominated in the roots and rhizosphere soil of P. yunnanensis, while both saprotrophic fungi and symbiotic fungi were in the roots and rhizosphere soil of E. citriodora. Our findings suggest that, following a forest fire, responses of fungal community are species-specific in Yunnan Plateau.

Key words: fungi, forest fire, rhizosphere soil, root, Pinus yunnanensis, Eucalyptus citriodora, Yunnan Plateau