An important fraction of terrestrial organic matter is translocated to aquatic ecosystem as dissolved or particulate organic matter (DOM, POM). This organic matter feeds microbial metabolism in the subsoil, lakes, rivers and the ocean. Dissolved and particulate organic carbon are key components of the global C cycle as a potential source of both CO2 and the stabilized carbon present in subsoils and sediments. Furthermore, dissolved organic nitrogen (DON), phosphorous (DOP) and sulfur (DOS) are integral parts of nutrient cycles in soils and waters. A comprehensive understanding of the dynamics of DOM and POM in terrestrial and aquatic ecosystems remains challenging due to complex interactions of biogeochemical and hydrological processes at different scales, i.e. from the molecular to the landscape scale. This session aims to improve our understanding of organic matter cycling from soil to water. We solicit contributions dealing with amounts, composition, reactivity and fate of DOM and POM and its constituents (i.e. C, N, P, S) in soils, lakes, rivers and the ocean as well as the impact of land use change and climatic change on these processes. In addition, it is important to recognize the key role of peatlands as sources of organic matter for many streams and rivers as well as soil erosion induced lateral fluxes of sediment and carbon at the catchment scale when assessing C dynamics across the terrestrial-aquatic continuum. Therefore, we aim to bring together scientists from various backgrounds, but all devoted to the study of dissolved and/or particulate organic matter using a broad spectrum of methodological approaches (e.g. molecular, spectroscopic, isotope, 14C, other tracers, modeling).