Soil fungal community structure and functional groups under different moisture gradients in Bitahai Wetland, Southwest China

Abstract:

[Objective] This study aims to analyze the fungal community structure and functional groups under different moisture conditions in Bitahai Wetland, which is expected to serve as a reference for wetland resource management and ecological restoration. [Methods] Perennially submerged swamp wetland (SW), seasonally submerged swamp meadow (SM), and non-submerged meadow (M) in Bitahai Wetland, Southwest China were investigated. Based on Illumina high-throughput sequencing and FUNGuild, the soil fungal community structure and functional groups of the three types were analyzed and compared, and the influence of key environmental factors on the fungal community was probed. [Results] The alpha diversity of soil fungi showed no significant difference among SW, SM, and M. Non-metric multidimensional scaling and similarity analysis suggested that beta diversity was significantly different among the moisture gradients (R=0.501, P=0.001). Bitahai Wetland was dominated by Ascomycota, Basidiomycota, Rozellomycota, and Mortierellomycota. The abundance of Basidiomycota, Rozellomycota, and Mortierellomycota varied significantly across different moisture gradients (P<0.05). Pyronemataceae, Mortierellaceae, Archaeorhizomycetaceae, and Clavariaceae were the dominant soil fungal families (P<0.05). Correlation analysis indicated that soil pH, total nitrogen, nitrate nitrogen, ammonium nitrogen, iron, potassium, and sucrose, and plant PCoA1 were in positive correlation with alpha diversity of soil fungi (P<0.05). Redundancy analysis and heat map analysis showed that soil water content, ammonium nitrogen, urease, and plant Shannon index were the main causes of beta diversity variation (P<0.05). Variance partitioning showed that the fungal community was affected by both single environmental factors and the interaction among various environmental factors, especially the interaction of soil factors and plant community. The trophic types of soil fungi in the Bitahai Wetland were mainly saprotroph and saprotroph-symbiotroph. SW was dominated by endophytic-phytopathogenic fungi, and SM and M by undefined saprophytes. As the moisture decreased, pathotroph-saprotroph-symbiotroph increased and functional groups showed higher complexity.[Conclusion]Moisture influences the structure and functional groups of soil fungi in the Bitahai Wetland, and its soil fungal diversity and composition are influenced by multiple environmental factors. The influence of environmental factors on fungal diversity and fungal phyla is different.

Key words:fungal community;function prediction;plant community;soil enzyme;Illumina high-throughput sequencing