Exploring the potential of d18O and d13C in pollen for reconstruction of Quaternary palaeo-climate: Pilot study towards a comprehensive calibration of stable isotopes in modern pollen from selected European plant taxa.

探索花粉中 d18O 和 d13C 重建第四纪古气候的潜力：对选定的欧洲植物类群的现代花粉中稳定同位素进行全面校准的试点研究。

基本信息

批准号：
277812067
负责人：
Dr. Gerhard Helle
金额：
--
依托单位：
Fachrichtung Paläontologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/277812067?language=en
关键词：
Exploring potential d18O d13C pollen

项目摘要

Analysis of the stable isotope compositions of plant-tissues and -compounds has myriads of applications spanning biology, climatology, ecology, and geology/palaeontology. Stable isotopic analysis of e.g. tree rings has provided a valuable tool to explore past climate variability as well as plant physiological responses to environmental change. Pollen assemblages that are preserved in terrestrial sedimentary systems offer an archive from which to gain insight into past environmental change and associated vegetation dynamics, typically covering the Quaternary and beyond. In this respect, stable isotopic analysis of pollen for palaeoenvironmental applications is a rather new approach in palaeoecological research. Literature on preliminary results from stable isotopic analyses of raw as well as extracted pollen exina suggest that significant potential exists to utilise palaeo-pollen records as quantitative indicators of past terrestrial palaeoenvironmental change over medium- to long-timescales. Moreover, by combining isotopic analyses with conventional pollen assemblages the information available is greatly enhanced, especially regarding the relative timing of plant community response to external forcing, e.g. climate. However, the applicability of stable isotope ratios in pollen is hampered by two challenges. Firstly, much more efforts need to be put in the calibration and verification of pollen-d13C and pollen-d18O as high quality climate or environmental proxies. Secondly, the labour intensive nature of the separation of sufficient numbers of grains required for reliable analyses. To tackle these challenges, we want to establish a pollen sampling network comprising 7 European sites differing in ecological conditions. The aim is to evaluate intra-seasonal isotope variability against instrumental climate data (initially over two years). At two sites we plan to analyse pollen isotope ratios from a large variety of annual and perennial plant taxa providing the natural inter- and intra-species baseline variability that will potentially allow a much better interpretation of the climatological or environmental significance of pollen isotope signatures. By comparing pollen isotope signatures of annual and perennial plants flowering at the same time of the vegetation period we intend to assess potential time lags and carry over effects in pollen isotope signatures of perennial plants, i.e. trees. The challenge of separating specific fossil pollen from lake sediments shall be approached in a first step by applying and testing split-flow lateral-transport thin separation cells for rapid and continuous particle fractionation (SPLITT), as well as a MicroBeam UV-laser catapult (ZEISS GmbH). Furthermore, we will use a novel, patented flash-pyrolysis-high-frequency-induction device coupled online to an IRMS that allows high throughput measurements of d13C and d18O by converting micro-amounts of organic samples to CO gas at temperatures of up to 2400°C.

对植物生物学，气候，生态学和地质学/古生物学的稳定同位素组成的分析。对环境变化的生理反应。除了Es extract的花粉外，还表明，在中等至时期的中等范围内，大量的丘陵 - 菌丝corlen corlen Corlen Corlen绳作为旋律的cantitors，通过将同位素分析与常规的花粉组合相结合，可以大大增强Y。植物社区的强迫，例如，有两个挑战，需要更多的挑战。足够的谷物数量来解决这些挑战，我们希望sampreng在生态条件下包含7个欧洲地点，以不同于季节性的同位素。分析各种各样的年度植物分类群的花粉同位比率，提供了自然的相互关系，这可能会更好地解释花粉同位素签名的气候或环境意义。我们有潜在的时间滞后，并在多年生植物的tope签名中，即树木分离化石沉积物与湖泊沉积物的挑战。快速且连续的粒子分级）Microbeam UV激光弹射器（Zeiss GmbH）。样品在高达2400°C的温度下可加为CO气体。