Multi-isotopic molecular records of rapid African terrestrial vegetation changes

本研究旨在探讨非洲植被对始新世和末次冰期快速气候波动的响应。已探测到与高纬度地区频繁气候变化有关的热带水文循环的突变。然而，陆地生物圈对千年尺度环境变化的实际响应尚不清楚。对非洲周围沉积物岩心的调查可以重建低纬度气候系统的快速变化。我建议利用新的分子同位素技术来识别和表征陆地植被的快速变化。将利用伍兹霍尔海洋研究所最新的气相色谱/飞行时间质谱仪（GC/TOF-MS）建立海洋沉积物岩心的超高分辨率（年代际到百年代际）植物脂质积累记录。随附的高分辨率植物脂质稳定碳和氢同位素记录将提供详细的气候信息。信号从大陆传递到沉积物的时间将通过陆源脂质组分的化合物特定放射性碳测年来研究。通过对气溶胶样品的分子同位素分析，将对风成过程进行表征。

The aim of the proposed research is to investigate the response of the African vegetation on rapid climatic fluctuations during the Honocene and the last Glacial. Abrupt changes in the tropical hydrological cycle linked with high-frequent climate variations of the high latitudes have been detected. However, the actual response of the terrestrial biosphere on the millennialscale environmental changes is yet unknown. Investigations of sediment cores around Africa allow the reconstruction of rapid changes in the low-latitude climate system. I propose to utilise novel molecular-isotopic techniques to identify and characterise rapid terrestrial vegetation changes. Ultra-highresolution (decadal to centennial) plant lipid-accumulation records from marine sediment cores will be established with the recently available Gas chromatography/Time-of-flight mass spectrometer (GC/TOF-MS) at Woods Hole Oceanographic Institution. Accompanying high-resolution plant lipid-specific stable carbon and hydrogen isotope records will supply detailed climatic information. The timing of the signal transfer from the continent to the sediments will be investigated by compoundspecific radiocarbon dating of terrigenous lipid fractions. With molecular-isotopic analyses of aerosol samples eolian transport processes will be characterised.