Abstract The composition and hydrogen isotope values of leaf wax components can be powerful tools in reconstructing past climate and environments. However, interpretation of past environmental conditions from such components in sediments is complicated by species-specific influences and there is a need to better understand how vegetation type affects leaf wax composition and isotope ratios in modern environments. In this study we analyzed leaf wax (n-alkane) distributions and hydrogen isotope values of plants from a high latitude ombrotrophic bog in northern Norway. The isotopic analysis of surface water was also conducted on samples from 15 lakes along a ca. 150 km transect to contextualize the bog water isotopic composition and constrain fractionation factors among n-alkane homologues. We identified 14 different plant types growing on the bog surface, including mosses, graminoids and other herbs, sub-shrubs and a tree. n-Alkanes from the leaves of the modern plants had average chain lengths from 25 to 30.5, with a variety of distributions, and with the dominant compound of longer chain lengths (C27, C29, or C31). δD values of n-C25 to n-C33 for the vegetation samples ranged from −197‰ to −116‰, with an average of −162‰. The data also revealed that the δD values for the homologues for half of the vegetation types had ranges that were ≥20‰. Using the average isotopic value of bog water samples, −60‰, we calculated apparent fractionation factors that ranged from −66‰ to −134‰ (avg. −108 ± 22‰), similar to other sites across Europe and to a global data compilation. Our results demonstrate the range of species-specific influences on leaf wax composition and isotopic values at this site and presumably other ombrotrophic bog environments, and provide a dataset to help evaluate the influence of vegetation type on regional sedimentary leaf wax records.

中文翻译：

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植被类型对高纬度嗜盐沼泽正构烷烃组成和氢同位素值的影响

摘要 叶蜡成分的组成和氢同位素值可以成为重建过去气候和环境的有力工具。然而，从沉积物中的这些成分解释过去的环境条件因物种特定的影响而变得复杂，需要更好地了解植被类型如何影响现代环境中的叶蜡成分和同位素比率。在这项研究中，我们分析了来自挪威北部高纬度 ombrotrophic 沼泽的植物的叶蜡（正烷烃）分布和氢同位素值。还对沿约 15 个湖泊的样本进行了地表水同位素分析。150 公里的横断面将沼泽水同位素组成和限制正构烷烃同系物之间的分馏因子纳入背景。我们确定了沼泽表面生长的 14 种不同植物类型，包括苔藓、禾本科植物和其他草本植物、亚灌木和一棵树。现代植物叶子中的正构烷烃的平均链长为 25 到 30.5，具有多种分布，并且主要化合物的链长较长（C27、C29 或 C31）。植被样本的 n-C25 至 n-C33 的 δD 值范围为 -197‰ 至 -116‰，平均值为 -162‰。数据还显示，一半植被类型的同源物的 δD 值范围≥20‰。使用沼泽水样本的平均同位素值 -60‰，我们计算了范围从 -66‰ 到 -134‰（平均 -108 ± 22‰）的表观分馏因子，类似于欧洲其他站点和全球数据汇编。