Data for dissolved organic matter and associated environmental variables across land–water continua of boreal catchments in Quebec [Québec, Canada, 2021-2024]

This dataset contains dissolved organic carbon (DOC) concentrations and PARAFAC-derived composition from terrestrial soil water (upland, riparian) and aquatic (stream, lake) compartments across 26 headwater catchments in four regions spanning the boreal and boreal-arctic transition of Quebec, Canada (48.9-59.1°N; 63.2-76.2°W) along with associated geographic and climatic variables. Sampling campaigns took place between July and August around La Romaine River (2021), Eastamain River (2022), Peribonka River (2023) and George River (2024).