Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (12): 1573-1584.DOI: 10.17521/cjpe.2022.0036

• Research Articles • Previous Articles    

Response of leaf-unfolding dates of woody species to variation of chilling and heat accumulation in warm temperate forests

YU Hai-Ying(), YANG Li-Lin, FU Su-Jing, ZHANG Zhi-Min, YAO Qi-Fu   

  1. College of Agroforestry Engineering and Planning, Guizhou Provincial Key Laboratory for Biodiversity Conservation and Utilization in the Fanjing Mountain Region, Tongren University, Tongren, Guizhou 554300, China
  • Received:2022-01-21 Accepted:2022-02-23 Online:2022-12-20 Published:2023-01-13
  • Supported by:
    National Natural Science Foundation of China(32160287);Talent Support Program for Common Colleges and Universities in Guizhou Province(Qian Education NO. [2017]088);Science and Technology Plan Project of Guizhou Province(Qian Science Basic-ZK[2022] General 560)


Aims In recent decades, the rapid climate warming had affected chilling and heat accumulation during winter and spring and made profound changes in plant spring phenology. To date, most related studies focused on either a range of species grown in various gardens or on experimental research, which may be not necessarily applicable to real-world conditions.

Methods By using leaf-unfolding data of 25 woody species during 2003-2019 in warm temperate forests of the Dongling Mountain, Beijing, we simulated the daily chilling and heat accumulation by applying partial least square regression, dynamic model and growing degree hour model. We then analyzed the response of leaf-unfolding dates to the variation of chilling and heat accumulation by linear regressions. Finally, the differences of leaf-unfolding dates and their responses to the variation of chilling and heat accumulation between shrubs and trees were compared by ANOVA.

Important findings The chilling periods of 25 woody species were from October 6 to March 17 of next year, with the forcing periods from January 21 to April 26. The corresponding chilling and heat accumulation were 66.16 chill portion (CP) and 2 933.12 growing degree hour (GDH) on average. The leaf-unfolding dates were delayed 3.54 d per 10 CP and 7.09 d per 1 000 GDH as the chilling and heat accumulation changed, with 2 and 23 species significant, respectively. This indicated that leaf-unfolding dates of woody species in warm temperate zone were mainly affected by heat accumulation. Moreover, the leaf-unfolding dates of shrubs were 3.87 d earlier and required 543.56 GDH less heat than trees. Species leafed earlier required less heat accumulation than those leafed out later, presumably due to the opportunistic strategy adopted by shrubs and early-leafing species. Sensitivity of leaf-unfolding dates of shrubs to heat accumulation (delayed 8.10 d per 1 000 GDH) existed marginally significant difference with trees (delayed 6.13 d per 1 000 GDH), which implied that leaf-unfolding dates of shrubs might advance faster than trees as global warming progresses.

Key words: plant phenology, leaf-unfolding date, climate warming, chilling accumulation, heat accumulation, warm temperate forests, woody species