整合生物学期刊网

林业研究(英文版) ›› 2024, Vol. 35 ›› Issue (1): 66-.DOI: 10.1007/s11676-024-01716-8

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Xiaomin Zeng1,a, Ping Ni1, Xiaohong Liu1, Wenzhi Wang2, Yao Li1, Wenchao Wang3,4   

  • 收稿日期:2023-08-09 接受日期:2023-12-13 出版日期:2024-10-16 发布日期:2024-10-16
  • 通讯作者: Xiaomin Zeng

Decline in tree-ring growth of Picea mongolica and its intra-annual eco-physiological responses to drought and CO2 enrichment in semi-arid China

Xiaomin Zeng1,a, Ping Ni1, Xiaohong Liu1, Wenzhi Wang2, Yao Li1, Wenchao Wang3,4   

  1. 1 School of Geography and Tourism, Shaanxi Normal University, 710119, Xi’an, People’s Republic of China
    2 The Key Laboratory of Mountain Environment Evolution and Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, 610041, Chengdu, People’s Republic of China
    3 CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, 110016, Shenyang, People’s Republic of China
    4 University of Chinese Academy of Sciences, 100049, Beijing, People’s Republic of China
  • Received:2023-08-09 Accepted:2023-12-13 Online:2024-10-16 Published:2024-10-16
  • Contact: Xiaomin Zeng

Abstract:

Episodes of drought-induced decline in tree growth and mortality are becoming more frequent as a result of climate warming and enhanced water stress in semi-arid areas. However, the ecophysiological mechanisms underlying the impact of drought on tree growth remains unresolved. In this study, earlywood and latewood tree-ring growth, δ13C, and δ18O chronologies of Picea mongolica from 1900 to 2013 were developed to clarify the intra- and inter-annual tree-ring growth responses to increasingly frequent droughts. The results indicate that annual basal area increment residuals (BAIres), which removed tree age and size effects, have significantly decreased since 1960. However, the decreasing trend of earlywood BAIres was higher than that of latewood. Climate response analysis suggests that the dominant parameters for earlywood and latewood proxies (BAIres, δ13C and δ18O) were drought-related climate variables (Palmer drought severity index, temperature, relative humidity, and vapor pressure deficit). The most significant period of earlywood and latewood proxies’ responses to climate variables were focused on June–July and July–August, respectively. BAIres, and δ13C were significantly affected by temperature and moisture conditions, whereas δ18O was slightly affected. Decreasing stomatal conductance due to drought outweighed the influence of increasing CO2 on intrinsic water use efficiency (iWUE), and ultimately led to a decline in BAIres. Compared to latewood, the faster decreasing BAIres and smaller increasing iWUE of earlywood suggested trees were more vulnerable to water stress in the early growing season. Our study provides insights into the inter- and intra-annual mechanisms of tree-ring growth in semi-arid regions under rising CO2 and climate change.

Key words: Tree growth, Drought, Water-use efficiency, Seasonal differences, Stable isotopes