Abstract The analysis of stable carbon and oxygen isotopes in tree-rings is a widely applied tool which allows to retrieve information about past climatic conditions, as well as tree physiological responses to environmental changes. This is based on well-established mechanistic models and firm statistical relationships with climate variables. In contrast, the hydrogen isotopic signature (δ2H) of tree-rings has been reported to be poorly correlated to climate or difficult to explain, and as a consequence, hydrogen isotopes are far less utilized. However, recent plant-physiological experiments have highlighted the role of autotrophic versus heterotrophic processes affecting δ2H values, i.e. use of fresh assimilates versus stored carbohydrates, and have much improved our understanding of the role of post-photosynthetic 2H-fractionation. Using unpublished and literature δ2H data of tree-ring cellulose (δ2HC) of 5 study sites in Europe and Asia, we systematically investigated the relationships between δ2HC and tree-ring width (TRW), which, in contrast to previous research, could now be explained through post-photosynthetic 2H-fractionation. In most cases, these relationships were found to be negative (r2 = 0.23 to 0.51, all P

中文翻译：

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不仅仅是气候：树木年轮中的氢同位素比率作为胁迫条件的新型植物生理指标

摘要 树轮中稳定碳和氧同位素的分析是一种广泛应用的工具，它允许检索有关过去气候条件的信息，以及树木对环境变化的生理反应。这是基于完善的机械模型和与气候变量的可靠统计关系。相比之下，据报道，树木年轮的氢同位素特征 (δ2H) 与气候的相关性较差或难以解释，因此，氢同位素的利用要少得多。然而，最近的植物生理实验强调了自养与异养过程影响 δ2H 值的作用，即使用新鲜同化物与储存的碳水化合物，并大大提高了我们对光合作用后 2H 分馏作用的理解。使用欧洲和亚洲 5 个研究地点的树轮纤维素 (δ2HC) 的未发表和文献 δ2H 数据，我们系统地研究了 δ2HC 与树轮宽度 (TRW) 之间的关系，与之前的研究相比，现在可以通过光合作用后的 2H 分馏来解释。在大多数情况下，发现这些关系是负的（r2 = 0.23 到 0.51，所有 P