Modular system for measuring carbon and nitrogen concentrations and isotopes

为了在不同的时间和空间尺度上对土地利用和气候变化的影响进行开创性的研究，需要一个用于测量土壤、沉积物、有机样品和水中的碳（C）和氮（N）的IRMS系统。得益于模块化设计，元素分析中的新系统既可以测量C和N浓度，也可以测量相应的稳定同位素。(1)土壤和沉积物中的C和N浓度是有机物存在的指标。这可以提供关于例如，农业造成的土壤退化、被侵蚀的表土物质（如果有机物质被冲入湖泊沉积物）或定居区的有机残留物（可能表明人类活动）。C含量的知识也是进一步分析的基础，例如生物标志物分析。(2)在地质考古学和考古植物学中，对植物残留物中稳定的氮同位素的测量表明使用了有机（绿色或粪肥）肥料，因为当地的氮同位素比率受土壤管理的影响而不是气候。拟议的跨学科项目可以填补重大的研究空白。在古生态学中，稳定碳和氮同位素的测量对于了解气候和植被历史非常重要。应用的例子是分析生态系统中C3和C4植物的比例与干旱的关系，这与热带稀树草原和草原的地质考古学和生态学研究有关，因为植物的同位素变化也反映在土壤和放牧动物中。新作物（如小米）的引入也可以在考古发现中使用碳同位素证明。(3)对于土壤侵蚀动力学的研究，从土壤中冲刷出来并溶解在水中的有机质的定量和定性是重要的。通过农田土壤侵蚀进入湖泊的有机质可导致湖泊沉积物δ 15 N和δ 13 C值的变化，这在史前时期也是可测量的。在这方面，我们对潜在过程的理解和解释沉积物中同位素数据的可能性仍然存在差距。这些系统的使用并不是地质考古学的标准应用。因此，碳和氮同位素的现场测量是开发方法和研究新研究问题的重要先决条件，这将是一个独特的机会，使我们在国际上成为生态地质考古研究中心。一个独特的补充将是测量土壤水中同位素的模块。

In order to conduct pioneering research related to the effects of land use and climate change on different temporal and spatial scales, an IRMS system for measuring carbon (C) and nitrogen (N) in soils, sediments, organic samples and water is required. Thanks to their modular design, new systems in element analysis allow both the measurement of C and N concentrations and the measurement of the respective stable isotopes. (1) C and N concentrations in soils and sediments are indicators for the presence of organic matter. This can provide information on, e.g., soil degradation due to agriculture, eroded topsoil material, if organic material has been washed into lake sediments, or organic residues in a settlement area that can indicate anthropogenic activities. Knowledge of the C content is also the base for further analysis, e.g. biomarker analysis. (2) In geoarchaeology and archaeobotany, the measurement of stable N-isotopes in plant residues indicates the use of organic (green or manure) fertilizer, since locally N-isotope ratios are rather influenced by soil management than by climate. Occurring major research gaps could be closed by the proposed interdisciplinary projects. In paleoecology, the measurement of stable C and N isotopes is important to gain insight into the climate and vegetation history. Examples of applications are the analyses of the proportion of C3 and C4 plants in an ecosystem as a function of aridity, which is relevant for geoarchaeological and ecological studies in savannas and steppes, where isotopic changes in plants are also reflected in soils and grazing animals. The introduction of new crops (e.g. millet) can also be demonstrated in archaeological findings using C isotopy. (3) For the study of soil erosion dynamics, the quantification and qualification of the organic matter that is washed out of the soil and dissolved in the water is important. The input of organic matter into lakes through soil erosion from agricultural land can lead to changes in δ15N and δ13C values of lake sediments, which was also measurable for prehistoric periods. Here, too, are still gaps in our understanding of the underlying processes and the possibility of interpreting the isotope data in sediments. The use of these systems is not a standard application in geoarchaeology. The on-site measurement of the C and N isotope is therefore an important prerequisite for developing methods and working on new research questions, and it would be a unique opportunity to position ourselves internationally as a center for ecological-geoarchaeological research. A unique addition would be the module for measuring the isotopes in soil water.