Trends over the last 50 years in global diatom taxonomy based on bibliometric analyses

Diatoms are key primary producers in aquatic food webs, and taxonomic research forms the foundation for understanding their biodiversity, ecosystem functions, and responses to environmental change. However, a systematic synthesis of taxonomic research and trends over time remains unquantified. This study employed bibliometric methods and the Latent Dirichlet Allocation (LDA) topic model to analyse literature from the Web of Science core collection spanning 1975–2025. The LDA model identified dynamic changes of research themes with regard to taxonomic research of diatoms. The analysis indicates that research hotspots have followed a clear trajectory from foundational taxonomic work to integration with ecological studies. Currently, the most active research fronts include new species morphology, riverine ecological indicators/biomonitoring applications, and molecular phylogenetics. This reflects that while the discipline continues to explore biodiversity, taxonomic research is integrated with and impacting environmental assessment and management practices. Notably, compared to these application- and discovery-oriented hotspots, foundational work essential for ensuring the long-term robustness of the classification system—such as taxonomic revision—receives less attention. This suggests a tension between knowledge production and systemic integration within the field, driven by the need to address pressing environmental challenges. This study posits that the future development of diatom taxonomy should, while continuing to leverage its applied potential, strengthen the systematic evaluation and integration of existing knowledge systems. This approach would build and strengthen the disciplinary foundation of taxonomic work, which complements and strengthens research areas such as biodiversity conservation and global change research as well as established and new applied areas of research.