Linking eucalyptus stump decomposition to microbial diversity, community composition, and metabolites

• Published in: Applied soil ecology : a section of Agriculture, ecosystems & environment Vol. 201; p. 105484
• Main Authors: Deng, Xiangsheng, Li, Xinyu, Yang, Mei, Lu, Wanmeng, Cheng, Fei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2024
• Subjects: Eucalyptus plantation; Metabolomics; Microbial communities; Microbial diversity; Stump decomposition; Succession; Microbial diversity; Stump decomposition; Metabolomics; Succession; Microbial communities; Eucalyptus plantation
• ISSN: 0929-1393; 1873-0272
• DOI: 10.1016/j.apsoil.2024.105484

In terrestrial ecosystems, microorganisms serve as primary decomposers of stumps, influencing carbon and nutrient cycling. However, our understanding of alterations in microbial communities driven by microbial-mediated metabolites within eucalyptus stump substrates of varying decay classes remains limited. Therefore, we conducted a 90-day laboratory incubation experiment using eucalyptus stump substrates representing five decay classes. Employing high-throughput sequencing and metabolomics, we evaluated microbial metabolites, community composition, diversity, and their interconnections. In the different decay classes of substrates, Proteobacteria, Actinobacteria, and Bacteroidetes were the dominant bacterial phyla. Despite the gradual increase of Basidiomycota across decay classes, Ascomycota persisted as the dominant fungal phylum. Acidothermus and Talaromyces genera were identified as primary microorganisms strongly associated with microbial metabolites. Partial least squares path modelling (PLS-PM) analysis revealed that microbial communities were primarily influenced by microbe-mediated metabolites, and available resource stoichiometry directly affected microbial alpha and beta diversity. The variations in stump bacterial and fungal community structures were explained by the presence of dissolved organic carbon (DOC) and ellagic acid. Random forest analysis indicated that total carbon (TC) of the stump was the most significant predictor of bacterial diversity. Moreover, total carbon to total phosphorus (TC:TP) and total nitrogen to total phosphorus (TN:TP) ratios of stumps were identified as pivotal factors influencing fungal diversity. Overall, our findings suggest that stump decomposition involves dynamic cross-kingdom succession and is significantly influenced by changes in substrate quality, with microbial-mediated metabolites exerting a pronounced and direct impact on microbial community diversity during the process. •During eucalyptus decomposition, bacterial succession was more pronounced than fungal.•Proteobacteria and acidobacteriota were pivotal in bacterial network, and ascomycota in fungal.•Acidothermus and Talaromyces genera were key microorganisms linked to metabolites.•Microbial communities influenced by metabolites where diversity by resource stoichiometry.