AUTHOR=Yongsheng Wu , Zilong Liao , Xiangqian Yu , Qiang Yin , Hui Wang , Li Gao 

TITLE=Stable isotopic analysis of water utilization characteristics of four xerophytic shrubs in the Hobq Desert, Northern China

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1103789

DOI=10.3389/fpls.2023.1103789

ISSN=1664-462X

ABSTRACT=<p>Quantitative identification of water utilization characteristics of xerophytic shrubs is an important prerequisite for the selection and optimization of a regional artificial sand-fixing vegetation system. In this study, a hydrogen (δD) stable isotope technique was used to study the changes in water use characteristics of four typical xerophytic shrubs, <italic>Caragana korshinskii</italic>, <italic>Salix psammophila</italic>, <italic>Artemisia ordosica</italic>, and <italic>Sabina vulgaris</italic> in the Hobq Desert under light (4.8 mm after 1 and 5 days) and heavy (22.4 mm after 1 and 8 days) rainfall events. Under light rainfall, <italic>C. korshinskii</italic> and <italic>S. psammophila</italic> primarily used the 80–140 cm layer of soil water (37–70%) and groundwater (13–29%), and the water use characteristics did not change significantly after the light rainfall event. However, the utilization ratio of <italic>A. ordosica</italic> to soil water in the 0–40 cm layer increased from less than 10% on the first day after rain to more than 97% on the fifth day after rain, whereas the utilization ratio of <italic>S. vulgaris</italic> to soil water in the 0–40 cm layer also increased from 43% to nearly 60%. Under heavy rainfall, <italic>C. korshinskii</italic> and <italic>S. psammophila</italic> still used the 60–140 cm layer (56–99%) and groundwater (~15%), while the main water utilization depth of <italic>A. ordosica</italic> and <italic>S. vulgaris</italic> expanded to 0–100 cm. Based on the above results, <italic>C. korshinskii</italic> and <italic>S. psammophila</italic> primarily use the soil moisture of the 80–140 cm layer and groundwater, while <italic>A. ordosica</italic> and <italic>S. vulgaris</italic> use the soil moisture of the 0–100 cm layer. Therefore, the co-existence of <italic>A. ordosica</italic> and <italic>S. vulgaris</italic> will increase the competition between artificial sand-fixing plants, while the combination of the two plants with <italic>C. korshinskii</italic> and <italic>S. psammophila</italic> will avoid competition between artificial sand-fixing plants to some extent. This study provides important guidance for regional vegetation construction and sustainable management of an artificial vegetation system.</p>