Chin J Plant Ecol ›› 2025, Vol. 49 ›› Issue (11): 1878-1889.DOI: 10.17521/cjpe.2025.0084  cstr: 32100.14.cjpe.2025.0084

• Research Articles • Previous Articles     Next Articles

Response of intra-annual radial growth of Juniperus przewalskii in the Qilian Mountains to hydrothermal factors

ZHANG Le, JIAO Liang*(), XUE Ru-Hong, ZHANG Peng, WANG Xu-Ge, QIN Ya-Rong, HOU Sai-Peng, MA Yuan-Yuan   

  1. College of Geography and Environment Sciences, Northwest Normal University, Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province, Lanzhou 730070, China
  • Received:2025-03-07 Accepted:2025-05-28 Online:2025-11-20 Published:2025-12-09
  • Contact: JIAO Liang
  • Supported by:
    National Natural Science Foundation of China(42371038);Basic Research Innovation Group Project of Gansu Province(22JR5RA129)

Abstract:

Aims The growth of trees is highly dependent on variations in the combination of external environmental factors such as precipitation and temperature. As a dominant coniferous species in the Qilian Mountains, Juniperus przewalskii’s growth dynamics in response to temperature and precipitation changes is crucial for the development of the forest ecosystem in the Qilian Mountains. Our objective is to identify the seasonal patterns of xylem formation of J. przewalskii and to clarify the characteristics of its intra-annual radial growth rate in response to variations in precipitation and temperature.

Methods This study selected five trees at altitude 3 000 m in the Qilian Mountains, collecting microcores from each tree every five days, and employed the microcoring method to complete laboratory experiments.

Important findings The results showed that: (1) The growth of J. przewalskii began around May 10 (day of the year (DOY) 131 ± 3) and ended around August 10 (DOY 223 ± 3), with a total growing season of (92 ± 2) d. (2) The dynamics of xylem cell number exhibited an S-shaped intra-annual trend, while the growth rate showed a Bell-shaped intra-annual trend, with a maximum growth rate of 0.32 units·column-1·d-1. The maximum growth rate occurred 12 d earlier than the summer solstice. (3) Hydrothermal variations emerge as primary drivers of intra-annual radial growth, with both temperature and precipitation demonstrating significant positive effects on growth rates. Notably, precipitation shows a more pronounced lagged effect on the growth of J. przewalskii. The findings of this study contribute to predicting future growth trends of J. przewalskii and provide theoretical support for understanding and protecting the sustainable development of the Qilian Mountains forest ecosystem.

Key words: xylem differentiation, hydrothermal variations, microcoring, radial growth, the Qilian Mountains