干旱区研究

Arid Zone Research ›› 2022, Vol. 39 ›› Issue (5): 1534-1542.doi: 10.13866/j.azr.2022.05.18

• Plant Ecology • Previous Articles     Next Articles

Physiological responses of a young Gansu elm (Ulmus glaucescens) to soil water loss and rehydration

ZHAO Zihan1(),WANG Shusen1,LUO Yuyang1,LIU Ruixiang1,HAN Feng2,MA Yingmei1()   

  1. 1. College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Key Laboratory of Desert Ecosystem Restoration and Protection, Hohhot 010011, Inner Mongolia, China
    2. College of Grassland and Environmental Resources, Inner Mongolia Agricultural University, Hohhot 010011, Inner Mongolia, China
  • Received:2022-02-07 Revised:2022-04-23 Online:2022-09-15 Published:2022-10-25
  • Contact: Yingmei MA E-mail:3037172860@qq.com;mym_youxiang@sina.com

RichHTML

9

PDF (PC)

311

Like

Abstract:

The physiological responses of young trees to soil water after afforestation in arid areas are important factors in water management and their survival. To provide a theoretical basis for water management in the cultivation of Gansu elm trees (Ulmus glaucescens), we analyzed the responses of morphology, physiology, and photosynthetic characteristics of young Gansu elm trees to different degrees of soil water loss and rehydration by using the potted method under mimicking natural water loss and rehydration conditions. The results showed that relative water content, chlorophyll content, and water use efficiency of Gansu elm leaves increased slightly by 14.8%, 1.2%, and 43.2%, respectively when the soil water loss was less (15%). The net photosynthetic rate, stomatal conductance, and transpiration rate of leaves decreased significantly by 26.5%, 27.1%, and 48.7%, respectively. When soil water content was at its lowest point (0%), the relative water content, chlorophyll content, and water use efficiency of Gansu elm leaves decreased significantly that the relative water content decreased by 78.4%, 65.4%, and 47.3%, respectively. There was a gradual decrease in the net photosynthetic rate, stomatal conductance, and transpiration, by the values of 89.9%, 83.3%, and 79.9% which were lower than the corresponding rates before soil water loss. One of the main reasons for the decline in the photosynthetic rate was the change in stomatal conductance. Rehydration can alleviate the adverse effects caused by soil water loss in Gansu elm. Therefore, in the environment of continuous soil water loss, Gansu elm adapts to the decline of soil water content through a series of changes in morphology, physiology, and photosynthetic characteristics by showing strong drought tolerance. In the case of severe soil water loss after planting, rehydration can alleviate the damage to Gansu elm trees.

Key words: Ulmus glaucescens, young trees, soil water loss, morphological and physiological characteristics, photosynthetic characteristics