Lipid and PAH composition as indicators for conditions of thermal degradation

脂质是土壤和沉积物中新鲜植物生物量和有机质的主要成分。单个植物和植物群携带特定的脂质分布模式，允许它们作为生物标志物应用。植物生物量的热降解，即在人为或野火期间，根据燃烧条件改变了分布模式。因此，燃烧条件可以根据主要脂质组分（如醇和酸）及其降解产物（包括脂肪族和多环芳烃（PAHs））的模式重建。在土壤和沉积物中就地结合的烧焦生物质将进行生物标志物分析。在一项实验中，温度、持续时间和热降解过程中氧气可用性对几种植物脂质分布模式的影响将被研究。实验结果与近期和化石土壤和沉积物中含有烧焦的生物质进行了比较。由于频繁燃烧和众所周知的燃烧历史，选择了最近的土壤，而根据考古文物选择了具有已知燃烧历史的古代土壤。该项目的结果首次利用土壤和沉积物中烧焦物质的脂质组成，促进了自然和人为改变生态系统中火灾条件和植被的重建。

Lipids are main components of fresh plant biomass and organic matter in soils and sediments. Individual plants and plant groups carry a specific lipid distribution pattern which allows for their application as biomarkers. Thermal degradation of plant biomass i.e. during anthropogenic or wildfires shifts the distribution patterns depending on burning conditions. Therefore, burning conditions may be reconstructed based on patterns of primary lipidic components like alcohols and acids as well as their degradation products including aliphatic and polycyclic aromatic hydrocarbons (PAHs). Charred biomass incorporated in situ in soils and sediments will be subjected to biomarker analyses. Within an experiment the influence of temperature, duration, and oxygen availability during thermal degradation on modification of lipid distribution patterns of several plant species will be investigated. Experimental results are compared to recent and fossil soils and sediments containing charred biomass. Recent soils are selected due to frequent burning and well known burning history, whereas ancient soils are selected with a known burning history based on archaeological artefacts. The results of the project facilitate for the first time the reconstruction of fire conditions and vegetation in natural and anthropogenically modified ecosystems by means of lipid composition of charred materials from soils and sediments.