Hydrogen isotopes in n-alkanes of tree leaves and needles: experimental studies with ecophysiological, ecosystem, climate, and dust-related applications

植物材料的稳定同位素作为天然生物化学示踪剂和环境和生理信号的整合剂，在生物学、生态学、地质学、气候科学和食品科学中具有广泛的意义。叶蜡（正构烷烃）中一个有趣的植物生化成分被提出作为沉积物中记录气候信号的生物标志物，并作为现代生态和食品科学应用的原产地信号。该项目的实验室实验和实地观察将测试一个数学模型，该模型说明环境和原产地的生化信号如何记录在叶蜡的稳定同位素中。我们最初的假设是，叶蜡中正构烷烃的氢同位素比记录了环境水的同位素比，这是已知的记录重要的地理和气候信息。还提出了替代假设，并将进行测试。利用气相色谱、质谱和同位素比值质谱技术，该项目将分析来自美国西部6个不同生态系统的36种多年生乔木和灌木。该项目的更广泛影响之一是在生物学、地质学和气候学之间建立新的跨学科联系。该项目的博士后培训将侧重于培养更有能力弥合这些学科共同利益的新科学家。研究结果将纳入犹他州年度国际稳定同位素生态学课程的讲座和实验室部分，该课程已经吸引了来自美国各地地理分布机构和世界各地强大机构的多学科研究生和博士后研究员。该项目的成果将纳入在http://stableisotopes.net上分发的网络模块。在这里，这项研究的更广泛影响将使用户能够探索同位素同位素的尺度模式，包括确定现代样品中正构烷烃的来源区域。

Stable isotopes of plant materials serve as natural biochemical tracers and integrators of both environmental and physiological signals that are of widespread interest in biology, ecology, geology, climate science, and food science. One interesting plant biochemical component in leaf waxes (normal-alkanes) is proposed to serve as both a biomarker in sediments recording climate signals and as a region-of-origin signal for modern ecological and food science applications. Laboratory experiments and field observations in this project will test a mathematical model of how an environmental and region-of-origin biochemical signal is recorded in the stable isotopes of leaf waxes. Our initial hypothesis is that the hydrogen isotope ratios of n-alkanes in leaf waxes record the isotope ratios of environmental water, which are already known to record significant geographic and climatic information. Alternative hypotheses are also proposed and will be tested. Using gas chromatography, mass spectrometry and isotope ratio mass spectrometry techniques, this project will analyze 36 perennial tree and shrub species from six different ecological systems across the western United States. One of the broader impacts of this project is to forge new interdisciplinary linkages among biology, geology, and climatology. Postdoctoral training in this project will focus on generating new scientists more capable of bridging the common interests of these disciplines. Research results will be incorporated into lecture and lab portions of an annual international stable isotope ecology course at Utah that already attracts a multidisciplinary spectrum of graduate students and post doctoral associates from geographically distributed institutions across the United States and from strong institutions around the world. The results of this project will be incorporated into web-based modules distributed at http://stableisotopes.net. Here the broader impacts of the research will allow users to explore isotope landscape-scale patterns, including determining source regions for n-alkanes in modern samples.