J Plant Ecol ›› 2023, Vol. 16 ›› Issue (1): rtac077.DOI: 10.1093/jpe/rtac077

• Research Articles •    

Accelerated warming in the late 20th century promoted tree radial growth in the Northern Hemisphere

Jie Liu1,2, Zong-Shan Li1,3,*, Maierdang Keyimu4, Xiaochun Wang5, Haibin Liang6, Xiaoming Feng1, Guangyao Gao1,3 and Bojie Fu1   

  1. 1 State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China, 2 University of Chinese Academy of Sciences, Beijing 100049, China, 3 National Observation and Research Station of Earth Critical Zone on the Loess Plateau in Shaanxi, Xi’an 710061, China, 4 State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China, 5 Center for Ecological Research, Northeast Forestry University, Harbin 15040, China, 6 Institute of Geographical Science, Taiyuan Normal University, Jinzhong 030619, China

    *Corresponding author. E-mail: zsli_st@rcees.ac.cn
  • Received:2022-03-29 Revised:2022-04-27 Accepted:2022-07-08 Online:2022-07-21 Published:2023-02-01

Abstract:

Accelerated global warming in the late 20th century led to frequent forest-decline events in the Northern Hemisphere and increased the complexity of the relationships between tree growth and climate factors. However, few studies have explored the heterogeneity of responses of tree growth to climate factors in different regions of the Northern Hemisphere before and after accelerated warming. In this study, a total of 229 temperature-sensitive tree-ring width chronologies from nine regions on three continents in the Northern Hemisphere were used in the data analysis performed herein. A bootstrapped correlation analysis method was used to investigate whether the tree growth-climate response changed significantly in different regions between the periods before and after rapid warming. Probability density functions and piecewise linear fitting were used to study the fluctuation characteristics of the tree-ring width indices before and after rapid warming. At the end of the 20th century (from 1977 to 2000), rapid warming significantly promoted the radial growth of trees in different regions of the Northern Hemisphere, but tree radial growth was heterogeneous among the different regions from 1950 to 2000. After 1976, except in central North America and northern Europe, the correlation between tree growth and temperature increased significantly in the Northern Hemisphere, especially in Asia. From 1977 to 2000, tree-ring index and temperature divergences were observed in nine regions with a divergence of 2–5 years. From 1950 to 2000, tree growth tracked better average temperature variability in the Northern Hemisphere than regional temperature.

Key words: climate warming, Northern Hemisphere, tree-ring, tree growth-climate relationship, divergence

摘要:
20世纪后期气候加速变暖促进了北半球树木径向生长
20世纪后期全球加速变暖导致北半球森林衰退事件频发,并增加了树木生长-气候关系的复杂性。然而,关于气候加速变暖前后北半球不同地区树木生长对气候因子响应的异质性研究仍较为缺乏。本研究利用北半球3大洲9个地区共计229条温度敏感型树轮宽度年表分析了气候加速变暖前后不同地区树木生长趋势和气候响应的异质性表现。结果表明:(i)1977–2000年期间,气候加速变暖显著促进了北半球不同地区树木的径向生长,但在1950–2000年期间,不同地区的树木径向生长表现出异质性特征。(ii)1976年后,除北美中部和欧洲北部,北半球树木生长和温度的相关性均显著增加,亚洲地区最为明显。(iii)在1977–2000年期间,9个地区的树木年轮指数与温度均出现了短暂的分离(2–5年)。在1950–2000年期间,各地区树木生长能够更好地追踪到北半球平均温度的变化趋势而不是区域温度。


关键词: 气候变暖, 北半球, 树轮, 树木生长-气候关系, 分离效应