Abstract
Soil microorganisms play pivotal roles in governing nutrient cycling, fertility maintenance, and carbon sequestration in terrestrial ecosystems. A three-year nitrogen enrichment experiment was conducted to investigate the consequences of nitrogen-induced stoichiometric imbalance on soil microbial communities in Pinus taiwanensis forests. Stoichiometric imbalance refers to a mismatch between the stoichiometry of soil nutrients and microbial biomass. Redundancy analysis (RDA) indicated that nitrogen enrichment predominantly correlates with shifts in the soil bacterial community, which are mainly associated with total soil carbon and available phosphorous. Changes in the soil microbial community were associated with the regulation of microbial biomass carbon and phosphorous. Fungal community variations were primarily influenced by increased nitrogen availability rather than soil acidification. Microbial communities influence nutrient restriction through dynamic adjustments to their structural composition. Additionally, a discernible relationship was identified between fungi and the carbon-to-nitrogen ratio of microbial biomass, as well as the carbon-to-phosphorous ratio of microbial biomass. We identified specific taxa from both Chloroflexi (bacteria) and Tremellomycetes (fungi) as biomarkers associated with specific particular nitrogen treatments. Chloroflexi establishes a specialized phosphorous-acquisition niche that not only supports its competitive survival in low-P soil environments but also facilitates its dominance in the microbial community. These biomarkers represent species with varying abundances that induce changes in microbial community structure. Notably, these taxa were identified as potential primary factors in microbial phosphorous limitation. The evidence, where vector A exceeds 45° , indicates that the soil is experiencing phosphorous limitation. Nitrogen enrichment did not exacerbate microbial carbon limitation but intensified phosphorous limitation, as evidenced by enzyme stoichiometry. These findings advance our understanding of how excess nitrogen alters soil microbial nutrient dynamics and community composition in subtropical forest ecosystems.
Data availability
The datasets generated during and/or analysed during the current study are available in the Supplementary Materials or from the corresponding author on reasonable request. The raw sequences obtained from this study have been uploaded to the NCBI Sequence Read Archive (PRJNA 666,625, PRJNA 775,067).
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Funding
This study was financially supported by the National Natural Science Foundation of China (32371846 and 42271301), University Natural Science research projects(2023AH051667) of Anhui Province and Anhui Postdoctoral Scientific Research Program Foundation(NO.2024C838), Outstanding Young Teacher Development Project of Anhui Provincial Department of Education(YQYB2023041), Research start-up funding for early-career doctoral professional (2022tlxyrc37).
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Juyan Cui and Yuehmin Chen wrote the main manuscript text and prepared Figs. 1–6. Juyan Cui: Funding acquisition;Writing – original draft, Data curation, Methodology, Software Yuehmin Chen: Conceptualization, Funding acquisition Xiaochun Yuan:Methodology,Visualization,Formal analysis. Quanxin Zeng: Data curation, Methodology, Software. Xiaoqing Zhang: Visualization, Investigation, Formal analysis. Yuan Jing: Funding acquisition, Methodology Xiaoli Gao:Visualization All authors reviewed the manuscript.
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Cui, J., Chen, Y., Yuan, X. et al. Short-term nitrogen enrichment alters microbial phosphorous limitation in Pinus taiwanensis forest soils. Sci Rep (2026). https://doi.org/10.1038/s41598-026-35511-8
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DOI: https://doi.org/10.1038/s41598-026-35511-8
