An empirical framework for large-scale modeling of dissolved organic carbon fluxes across soils and water

Past changes in climate, land-use and atmospheric deposition patterns have had major impact on nutrient distribution on land, and on the export of dissolved organic carbon (DOC) to aquatic systems, leading to an apparent "brownification" of surface waters. There is now an urgent need to assess the impact of continued environmental change on future carbon cycling across terrestrial and aquatic systems, both on local and regional scales.

By combining our expertise in biogeochemistry and ecosystem modelling, we will explore the previously unanswered question of how multiple factors together affect DOC on the landscape level, thus contributing to awareness of how human perturbation affects surface water browning. First, we will validate, test and redefine the parameters and assumptions related to DOC dynamics in the dynamic large-scale ecosystem model LPJ-GUESS. We will then use knowledge about hydrological connectivity to scale up the model from the local to the regional level, providing the basis for large-scale model projection of DOC fluxes in both terrestrial and aquatic systems. The Krycklan catchment, Northern Sweden, will serve as field site for evaluation of model improvement. Sample-intense DOC degradation experiments will be facilitated by a state-of-the-art field and laboratory infrastructure. Our project group represents a novel collaboration between experts in the field of DOC cycling and within large-scale ecosystem modelling.