Data supporting "Seasonal Molecular and Microbial Reorganization beneath a Persistent DOM Pool in a High-Altitude River

This dataset contains the processed and analysis-ready data supporting the manuscript “Seasonal Molecular and Microbial Reorganization beneath a Persistent DOM Pool in a High-Altitude River.” The study examines seasonal variation in dissolved organic matter (DOM) molecular composition, bacterial community characteristics, and DOM–bacterial coupling in the middle reaches of the Yarlung Tsangpo River on the Tibetan Plateau. Samples were collected during two sampling campaigns, in December 2024 (winter) and June 2025 (summer). Sample identifiers consist of a letter indicating the sampling period followed by the site number. “D” denotes samples collected in December 2024, whereas “J” denotes samples collected in June 2025. Samples sharing the same numerical identifier represent the same sampling site surveyed during the two sampling periods; for example, D12 and J12 correspond to Site 12 sampled in December 2024 and June 2025, respectively. Detailed geographical and sampling-site information is provided in the Supporting Information of the associated manuscript. The dataset consists of five data tables. 01_Bacterial_OTU_Taxonomy_and_Abundance.xlsx contains bacterial operational taxonomic unit (OTU) taxonomic annotations and sample-level abundance data derived from 16S rRNA gene amplicon sequencing. 02_FTICRMS_DOM_Molecular_Formula_and_Intensity.xlsx contains molecular formula assignments, molecular properties, classifications, and sample-level signal intensities obtained by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). 03_Physicochemical_Variables.xlsx contains the physicochemical and environmental variables measured for the sampled river waters. 04_DOM_Molecular_and_Fluorescence_Indices.xlsx contains sample-level DOM molecular properties and fluorescence-derived indices calculated from FT-ICR-MS and fluorescence spectroscopy data. 05_Bacterial_Community_Diversity_and_Ecological_Indices.xlsx contains bacterial community diversity metrics and ecological indices used in the statistical analyses. 00_README provides additional information on file contents, variable definitions, sample naming conventions, and data interpretation. These datasets were used for the statistical analyses and figures reported in the associated manuscript and are provided here to enable confidential editorial assessment and peer review prior to public release.