The role of inland waters in regional and global C budgets is receiving increased attention, and much has been speculated on the importance of tropical systems, and the extent to which they differ fundamentally from temperate systems. This sessions sollicits contributions that shed new light on the biogeochemical functioning of tropical rivers, reservoirs, wetlands and lakes, as well as global datasets that investigate the regional distribution of fluxes or processes in inland waters and their drivers. We welcome all aspects of carbon-related biogeochemistry, including but not limited to the transport, emission, recycling, and retention of sediments, organic matter, nutrients and dissolved gases. Conceptual and mathematical biogeochemical modelling, based for instance on aquatic metabolism and greenhouse gas fluxes, field studies and regional C budgets through the tropical terrestrial-aquatic continuum are also very relevant.