A bibliometric and narrative review on the sources and structure of Dissolved Organic Matter (DOM) in lakes: A China perspective

This review provides a comprehensive examination of Dissolved Organic Matter (DOM) in aquatic environments, with a particular focus on lakes in China. DOM is a carbon-dominated mixture composed mainly of carbon, hydrogen, and oxygen, with nitrogen, and phosphorus as biogeochemically important minor constituents. It connects catchments, lake food webs, sediments, and the atmosphere, but dissolved organic carbon (DOC) remains a bulk sum parameter that cannot identify trace organic contaminants or particulate plastics. This review traces publication development from 1991 to2025 and evaluates laboratory measurements, optical spectroscopy, remote sensing, stable-isotope analysis, and ultrahigh-resolution mass spectrometry. A Web of Science topic search retrieved 1,213 lake-DOM publications, while a separate author-keyword search for chromophoric dissolved organic matter and remote sensing retrieved 120 publications for complete years 1997-2025. A literature-derived map shows descriptive regional differences among five Chinese lake regions, with the highest compiled mean DOC concentrations in the Mongolian-Xinjiang and Tibetan-Qinghai Plateau regions; these aggregates are not formal meta-analytic estimates. Catchment hydrology, trophic state, salinity, ice, stratification, photochemistry, microbial processing, and sediment exchange jointly regulate DOM quantity and composition. DOM also acts as a reactive ligand, colloidal carrier, and microbial substrate, making its effects on eutrophication, trace-element mobility, and greenhouse-gas production conditional rather than uniformly enhancing or suppressing. The review highlights method boundaries, regional evidence, limitations, and priorities for integrated monitoring and sustainable lake management.