Variation of arbuscular mycorrhizal fungi communities in the rhizosphere soil of Eucalyptus plantations based on different stand ages and its effect on phosphorus fractionation

Arbuscular mycorrhizal fungi (AMF) communities are strongly linked to soil available phosphorus levels in Eucalyptus plantations. AMF frequently collect and route considerable amounts of P to their host plants, likely through collaboration with other soil nutrients. Nevertheless, the mechanism of AMF driving available P in Eucalyptus plantation soil remains ambiguous. This paper aimed to determine the effect of the AMF community structure on available P in Eucalyptus soil. Four Eucalyptus stands including 1-, 3-, 5-, and 12-year-old (abbreviated as SA1, SA3, SA5, and SA12, respectively) were obtained from a national forest farm. High-throughput sequencing and a modified Hedley technique for soil P fractionation were used to investigate the AMF community structure. Our results revealed the P fractionation and the structure of the AMF community in SA5 and SA12 are highly variable compared with the control. Redundancy analysis showed the AMF taxa are closely connected with the available P in soil. Glomeraceae and Paraglomeraceae have a strong influence on resin P, inorganic P extracted by concentrated hydrochloric acid, residual P that is difficult to extract, as well as ammonium nitrogen and pH. The structural equation model indicated that soil properties have a significant influence on AMF diversity and abundance, and AMF dominant species support organic P (NaHCO3-Po) conversion. These results implied that Eucalyptus stand ages alter the soil physical and chemical properties, which affect the AMF colonization capacity. AMF also has a significant influence on the available P content of the soil. Glomeraceae and Paraglomeraceae are the dominant fungi influencing the available P content. Furthermore, expanding Glomeraceae and Paraglomeraceae, and applying them to Eucalyptus plantation may improve soil P availability. Finally, the structure of the AMF community may be a sensitive indicator of the quality of soil available P in Eucalyptus plantation.