Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (9): 1086-1097.DOI: 10.17521/cjpe.2021.0495

• Research Articles • Previous Articles     Next Articles

Hydraulic regulation of Populus tomentosa and Acer truncatum under drought stress

WU Min1, TIAN Yu2, FAN Da-Yong3, ZHANG Xiang-Xue1,*()   

  1. 1College of Science, Beijing Forestry University, Beijing 100083, China
    2College of Biological Science and Technology, Beijing Forestry University, Beijing 100083, China
    3Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing 100083, China
  • Received:2021-12-28 Accepted:2022-03-07 Online:2022-09-20 Published:2022-10-19
  • Contact: ZHANG Xiang-Xue
  • Supported by:
    National Natural Science Foundation of China(31670625)


Aims The tree decline and death caused by drought stress under global climate change is a topic of general interest in ecological research. Different tree species in the same habitat can adopt various hydraulic strategies to maintain water balance in order to deal with drought stress. Populus tomentosa and Acer truncatum are the main tree species in plantations in the North China Plain. Studies on their hydraulic structure and dynamics of non-structural carbohydrate (NSC) content during drought-rehydration can reveal their hydraulic regulation strategies and provide theoretical basis for scientific management of water balance in plantations in north China under the background of global climate change.

Methods By using the saplings of P. tomentosa and A. truncatum distributed in the same habitat, we measured the hydraulic structure parameters, such as the resistance to embolism and hydraulic safety margin of stem, hydraulic areas, osmotic potential at leaf turgor pressure loss point, etc. Dehydration and rehydration were carried out to investigate the dynamics of stem NSC content, and to examine the repair capacity of xylem embolism in the rehydration stage after drought stress removel.

Important findings The results showed that the water potential of P. tomentosa (-1.289 MPa) when xylem hydraulic conductivity lost 50% was higher than that of A. truncatum(-2.894 MPa). Populus tomentosa also presented lower osmotic potential at turgor pressure loss point, narrower hydraulic safety margin, smaller wood density, and tended to have anisohydry behavior of stomatal regulation, indicating that it was prone to embolism characterized with dehydration and drought tolerance at low water potential, and tended to have more risky water regulation strategies. Acer truncatum survived drought stress by “delayed dehydration” at high water potentials, and tended to have conservative water regulation strategy. In the dehydration-rehydration experiment, the contents of soluble sugar, starch and non-structural carbohydrate in stem of P. tomentosa decreased first and then increased, while those of A. truncatum increased first and then decreased, and P. tomentosa showed a higher embolic repair ability than A. truncatum, which was related to the difference of stem NSC content. The higher embolism repair ability of P. tomentosa can provide hydraulic safety guarantee for risky water regulation strategies and drought tolerance strategy. There were significant differences between P. tomentosa and A. truncatum in the regulation of hydraulics, which might be related to the characteristics of life history.

Key words: hydraulic regulation, water regulation countermeasure, non-structural carbohydrate, embolism repair, drought tolerance characteristic