Acta Geographica Sinica ›› 2021, Vol. 76 ›› Issue (5): 1193-1205.doi: 10.11821/dlxb202105011

• Climate Change and Land Surface Processes • Previous Articles     Next Articles

Stable nitrogen isotope in tree rings: Progresses, problems and prospects

WANG Keyi1(), LIU Xiaohong1,2,3(), ZENG Xiaomin1, XU Guobao2, ZHANG Lingnan1, LI Chunyue1   

  1. 1. School of Geography and Tourism, Shaanxi Normal University, Xi'an 710119, China
    2. State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, CAS, Lanzhou 730000, China
    3. Qinghai Research Center of Qilian Mountain National Park, Xining, Qinghai 810008, China
  • Received:2020-05-18 Revised:2021-03-12 Online:2021-05-25 Published:2021-07-25
  • Contact: LIU Xiaohong E-mail:wky@snnu.edu.cn;xhliu@snnu.edu.cn;liuxh@lzb.ac.cn
  • Supported by:
    National Natural Science Foundation of China(41971104);The Fundamental Research Funds for the Central Universities(GK202107009);The Open Foundation of the State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment(SKLLQG1817);The Qilian Mountain National Park Research Center (Qinghai)(GKQ2019-01)

Abstract:

Stable isotope in tree rings are effective proxies for the study of climate change and environmental evolution. Coupling analysis of stable isotope records of tree rings can reveal the spatiotemporal variation characteristics and interactions of carbon, water and nitrogen in forest ecosystems, and reflect the physiological effects of environmental changes on plant-specific compounds. The stable nitrogen isotope ratio (δ15N) in tree rings is closely related to the environmental conditions of tree growth, and the change of ratio can indicate the dynamic characteristics of nitrogen cycle in forest ecosystem on a long-term scale, and make up for the lack of monitoring data. Herein, we reviewed the theory of the stable nitrogen isotope fractionation and measuring method, and found out the issues that need to be paid attention to in sample pretreatment and measurement. Furthermore, we synthetically stated and evaluated the reports of climate and environment evolution based on δ15N of tree-rings, and the effects of human activities on nitrogen cycle in forest ecosystem. We suggested the great potential of tree-ring δ15N in combination of the multiple isotope proxies and its development directions in the future, which should promote further studies on the spatiotemporal characteristics of nitrogen cycle in forest ecosystems.

Key words: tree ring, stable nitrogen isotope ratio, climate change, nitrogen cycle, forest ecosystem