Variations in Arbuscular Mycorrhizal Fungi Communities During Wetland and Forest Succession in Northeast China

In this study, we investigated the changes in the communities of arbuscular mycorrhizal fungi (AMF) and their driving factors across eight vegetation succession stages in the Sanjiang Plain, Northeast China, original natural wetland (NW), wetland edge (EW), shrub-invaded wetland (IW), shrub-dominated wetland (DW), young-Betula forest (YB), mature-Betula forest (MB), Populus and Betula mixed forest (PB), and conifer forest (CF), using Illumina MiSeq sequencing. As this research has revealed, significant differences exist in soil physicochemical indicators, including moisture content (MC), pH, soil organic carbon (SOC), total nitrogen (TN), available nitrogen (AN), total phosphorus (TP), and available phosphorus (AP). As vegetation succession progresses, the diversity and structure of AMF communities also undergo changes, with the Simpson diversity index being highest in coniferous forests (CF) and the Abundance-based Coverage Estimator (ACE) and Chao1 indices being elevated in shrub-dominated wetlands (PB). Non-metric multidimensional scaling (NMDS) analysis reveals distinct differences in AMF communities across various succession stages. Furthermore, stacked bar charts indicate that the genus Glomus dominates in most wetland and forest succession stages but is nearly absent in CF, where it is replaced by the genus Paraglomus. Canonical correspondence analysis (CCA) demonstrates that SOC has a more significant impact on AMF communities during the EW stage of succession, while AP and TP exert greater influence during the CF stage as well as the MB and YB stages. AN, on the other hand, plays a more prominent role in shaping AMF communities during the IW and NW stages. PICRUSt2 predictions reveal that enzymes such as alcohol dehydrogenase and L-aminoadipate-semialdehyde dehydrogenase are most abundant in YB, whereas pathways like 4-amino-2-methyl-5-diphosphomethylpyrimidine biosynthesis are most enriched in IW. These findings uncover the close interplay between soil physicochemical properties and AMF community dynamics, aiming to deepen our understanding of the relationships among soil physicochemical properties, AMF community changes, and succession dynamics in wetland and forest ecosystems.