Tracing the origin of sediments and C across the terrestrial-aquatic continuum: a holistic approach to assess climate change and water quality threat

Tracing the sources of sediment and organic carbon (OC) in the fluvial environment is key to supporting sustainable land management decisions and maintaining ecosystem services. A recent pilot-study, conducted by the supervisory team, showed that by combining plant-derived biomarkers (n-alkanes) with bulk stable isotopes (13C, 15N) it is possible to distinguish OC and sediment provenance from different land uses3. However, this study highlighted the need for considering other novel tracers, the spatial downscaling of the representation of the identified fluxes will be crucial methodological improvements in this context. Hence, the present PhD study will be the first to develop a modelling approach to identify pathways of OC in a temporal and spatial detailed way (intra-field and intra-annual variability) by consider various existing modern large databases (land use, soil type, remote sensing (MODIS) and topography). This novel approach will be validated by an improved tracing technique based on compound-specific-stable-isotope analyses (CSSIA) of fatty acids and n-alkanes as an independent measure.