树轮稳定同位素记录:进展、问题及展望

树轮稳定同位素比率(δ13 C、δ18O 和δD)变化与树木生长季的气候和环境条件密切相关。控制实验表明, 树轮稳定同位素比率变化可较好地记录树木叶片气孔活动、水分来源、水分利用效率等相关信息, 已成为古气候和全球变化生态学研究的重要代用指标和手段之一。树轮稳定同位素记录能够较好地保留低频气候环境变化信息, 与年轮宽度相结合, 可有效地进行区域古气候重建和全球变化生态学方面的研究。文章综述了树轮稳定同位素的分馏机理及其发展, 系统阐述和评价了利用树轮稳定同位素指标进行古气候和古环境的相关研究成果, 并指出树轮稳定同位素研究在中国未来亟须着重发展的方向。

TREE-RING STABLE ISOTOPES PROXIES: PROGRESS,PROBLEMS AND PROSPECTS

Stable isotope ratios (carbon, hydrogen and oxygen) in tree rings are closely related to the climate and environment conditions of trees growing period. Controlled experiments suggested that stable isotopes ratios recorded the information of water source, drought, intrinsic water-use efficiency and others. Tree-ring stable isotopes have become one of the important proxies in paleoclimate and global change ecology investigations. Tree-ring stable isotopes could retain low-frequency climate change signals, and it can be used to reconstruct paleo-climate and to study in term of global change in ecology by combing with tree-ring width proxy. Herein, we reviewed the theory of the tree-ring stable isotope fractionation, and assessed the results of the paleoclimate and environment using the tree-ring stable isotopes. We paid more attention on the progresses on the tree-ring stable isotopes over the different climatic regimes of China. We concluded that the tree-ring carbon stable isotope is a good proxy for the temperature variability, and the tree-ring oxygen stable isotope is a good indicator for the moisture condition in arid and semi-arid China. Lastly, we suggested the future developing terms of the tree-ring stable isotopes investigations in China.