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记物(正构烷烃)与大宗稳定同位素(13C、15N)相结合，可以区分不同土地用途的有机碳和沉积物来源3。然而，这项研究强调了考虑其他新示踪剂的必要性，在这方面，对已确定通量的表示进行空间缩小将是关键的方法学改进。因此，本PHD研究将首次开发一种模型方法，通过考虑现有的各种现代大型数据库(土地利用、土壤类型、遥感(MODIS)和地形)，以时间和空间详细的方式(田内和年内变化)确定有机碳的路径。这一新的方法将通过一种改进的追踪技术进行验证，该技术基于脂肪酸和正构烷烃的化合物特定稳定同位素分析(CSSIA)作为一项独立的衡量标准。

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.