Data for: Tree xylem water isotope analysis by Isotope Ratio Mass Spectrometry and Laser Spectroscopy: a dataset to explore drought response

The use of xylem isotopes is an increasingly commonly used approach in eco-hydrological studies. Carrière et al. [2019] used this dataset to better understand where trees uptakes water under drought condition on a Mediterranean karstic system. Despite this technique is widely used, analytical issues still discussed within user community. We have conducted a number of tests which are relevant to be shared to animate the debate. We show that mass and laser spectrometer analyzes give very similar results for 46 xylem water and 9 drainage water samples. The full dataset (219 samples) shows that the xylem water undergo a deuterium fractionation which make the deuterium data unusable in the current state.

木质部(xylem)同位素分析在生态水文学研究中的应用愈发广泛。Carrière等人[2019]依托本数据集，旨在更清晰地阐明地中海喀斯特地貌系统内，干旱条件下树木的水源摄取位点。尽管该技术已得到广泛应用，但用户群体中仍存在诸多有待探讨的分析方法相关问题。为此我们开展了多项相关测试，以期分享研究成果以推动相关学术讨论。研究表明，针对46个木质部水样本与9个排泄水样本，质谱仪(mass spectrometer)与激光光谱仪(laser spectrometer)的分析结果高度一致。完整数据集（共计219个样本）显示，木质部水会发生氘(deuterium)分馏作用，导致当前状态下的氘同位素数据无法使用。