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

追踪河流环境中沉积物和有机碳（OC）的来源是支持可持续土地管理决策和维持生态系统服务的关键。监督小组最近进行的一项试点研究表明，通过将植物来源的生物标志物（正烷烃）与大块稳定同位素（13C, 15N）相结合，可以区分不同土地用途的OC和沉积物来源3。然而，这项研究强调了考虑其他新型示踪剂的必要性，在这种情况下，已确定通量的空间降尺度表示将是关键的方法改进。因此，目前的博士研究将是第一个开发一种建模方法，通过考虑各种现有的现代大型数据库（土地利用、土壤类型、遥感（MODIS）和地形），以时间和空间的详细方式（田内和年内变化）确定OC的途径。这种新方法将通过一种基于脂肪酸和正构烷烃化合物特异性稳定同位素分析（CSSIA）作为独立测量的改进示踪技术进行验证。

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.