IASMA Research and Innovation Centre-Fondazione Edmund Mach, Via E. Mach 1, 38010, San Michele all'Adige, Italy.
Rapid Commun Mass Spectrom. 2013 Jan 15;27(1):265-75. doi: 10.1002/rcm.6446.
Carbon, hydrogen and oxygen (C, H and O) stable isotope ratios of whole wood and components are commonly used as paleoclimate proxies. In this work we consider eight different proxies in order to discover the most suitable wood component and stable isotope ratio to provide the strongest climate signal in Picea abies in a southeastern Alpine region (Trentino, Italy).
δ(13)C, δ(18)O and δ(2)H values in whole wood and cellulose, and δ(13)C and δ(2)H values in lignin methoxyl groups were measured. Analysis was performed using an Isotopic Ratio Mass Spectrometer coupled with an Elemental Analyser for measuring (13)C/(12)C and a Pyrolyser for measuring (2)H/(1)H and (18)O/(16)O. The data were evaluated by Principal Component Analysis, and a simple Pearson's correlation between isotope chronologies and climatic features, and multiple linear regression were performed to evaluate the data.
Each stable isotope ratio in cellulose and lignin methoxyl differs significantly from the same stable isotope ratio in whole wood, the values begin higher in cellulose and lignin except for the lignin δ(2)H values. Significant correlations were found between the whole wood and the cellulose fractions for each isotope ratio. Overall, the highest correlations with temperature were found with the δ(18)O and δ(2)H values in whole wood, whereas no significant correlations were found between isotope proxies and precipitation.
δ(18)O and δ(2)H values in whole wood provide the best temperature signals in Picea abies in the northern Italian study area. Extraction of cellulose and lignin and analysis of other isotopic ratios do not seem to be necessary.
碳、氢和氧（C、H 和 O）的整木及成分稳定同位素比值通常被用作古气候代用指标。在这项工作中，我们考虑了八种不同的代用指标，以便在意大利东南部阿尔卑斯山地区（特伦蒂诺）的云杉中发现最适合提供最强气候信号的木材成分和稳定同位素比值。
测量了整木和纤维素中的 δ(13)C、δ(18)O 和 δ(2)H 值，以及木质素甲氧基中的 δ(13)C 和 δ(2)H 值。使用同位素比质谱仪与元素分析仪联用测量（13）C/（12）C，使用热解器测量（2）H/（1）H 和（18）O/（16）O 来进行分析。通过主成分分析对数据进行评估，并对同位素年表与气候特征之间进行简单的皮尔逊相关分析，以及进行多元线性回归来评估数据。
纤维素和木质素甲氧基中的每种稳定同位素比值与整木中的同一稳定同位素比值差异显著，除了木质素 δ(2)H 值外，纤维素和木质素的数值开始较高。在每个同位素比值中，整木与纤维素部分之间均存在显著相关性。总体而言，与温度相关性最高的是整木的 δ(18)O 和 δ(2)H 值，而同位素代用指标与降水之间没有显著相关性。
在意大利北部研究区的云杉中，整木的 δ(18)O 和 δ(2)H 值提供了最佳的温度信号。似乎没有必要提取纤维素和木质素并分析其他同位素比值。
