Carbon, hydrogen and oxygen stable isotope ratios of whole wood, cellulose and lignin methoxyl groups of Picea abies as climate proxies
Carbon, hydrogen and oxygen stable isotope ratios of whole wood, cellulose and lignin methoxyl groups of Picea abies as climate proxies
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DOI：
10.1002/rcm.6446
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发表时间：
2013-01-15
影响因子：
2
通讯作者：
Camin, F.
中科院分区：
文献类型：
--
作者：
Gori, Y.;Wehrens, R.;Camin, F.
理论基础全木及其组分的碳、氢、氧（C、H、O）稳定同位素比值是常用的古气候指标。在这项工作中，我们考虑了八种不同的代用指标，以发现最合适的木材成分和稳定的同位素比率，以提供意大利特伦蒂诺东南部阿尔卑斯地区云杉树最强烈的气候信号。方法测定全木材和纤维素中的δ 13C、δ 18O和δ 2H值，以及木质素甲氧基中的δ 13C和δ 2H值。采用同位素比质谱联用13C/12C元素分析仪和2H/1H和18O/16O热裂解仪进行分析。利用主成分分析、同位素年代学与气候特征间的Pearson相关性和多元线性回归对数据进行评价。结果纤维素和木质素甲氧基的各稳定同位素比值与全木的相同稳定同位素比值差异显著，除木质素δ 2H值外，纤维素和木质素的稳定同位素比值开始较高。在各同位素比值下，整个木材与纤维素组分之间存在显著的相关性。总体而言，整个木材的δ 18O和δ 2H值与温度的相关性最高，而同位素指标与降水的相关性不显著。结论意大利北部研究区云杉全木δ 18O和δ 2H值提供了最佳的温度信号。纤维素和木质素的提取和其他同位素比率的分析似乎没有必要。版权所有：John Wiley & Sons， Ltd。
RATIONALE 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). METHODS delta 13C, delta 18O and delta 2H values in whole wood and cellulose, and delta 13C and delta 2H values in lignin methoxyl groups were measured. Analysis was performed using an Isotopic Ratio Mass Spectrometer coupled with an Elemental Analyser for measuring 13C/12C and a Pyrolyser for measuring 2H/1H and 18O/16O. 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. RESULTS 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 delta 2H 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 delta 18O and delta 2H values in whole wood, whereas no significant correlations were found between isotope proxies and precipitation. CONCLUSIONS delta 18O and delta 2H 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. Copyright (c) 2012 John Wiley & Sons, Ltd.