Water Use Characteristics of Populus euphratica Oliv. and Tamarix chinensis Lour. at Different Growth Stages in a Desert Oasis

Yanbo Wan,Qingdong Shi,Liping Peng,Lei Peng,Nijat Marhaba,Yue Dai,Haobo Shi

doi:10.3390/f13020236

Yanbo Wan, Qingdong Shi + Show 5 more

Open Access

https://doi.org/10.3390/f13020236

Copy DOI

Abstract

Understanding the water use characteristics of vegetation is crucial for guiding the rational allocation of water resources and the restoration of sustainable vegetation in natural oases in arid desert areas. To analyze the water use characteristics of Populus euphratica Oliv. and Tamarix chinensis Lour. at different stages of growth in the Daliyabuyi natural pristine oasis in northwestern China, the δ18O values of plant xylem of 15 sample trees with different sizes per species, potential water sources (i.e., river water, soil water, and groundwater), and the δ13C values of plant leaves of sample trees were measured in August 2019 and June 2020. The results show that the δ18O values of the xylem water of P. euphratica at different growth stages were similar, but water uptake proportions from deep soil water changed in P. euphratica trees at different growth stages between years with (2019) and without (2020) river water. In contrast, the main water source of young T. chinensis shrubs was deep soil water, and those of mature and overmature shrubs were deep soil water and groundwater in 2020. However, the plant leaf water use efficiency (WUE) of the P. euphratica and T. chinensis were higher without river water. Overall, the water uptake proportion from groundwater and the WUE for T. chinensis were higher than those for P. euphratica, and thus, T. chinensis was more dependent on groundwater. This means that vegetation types and growth stages are the essential factors to be considered in ecological restoration management, which can enhance the effectiveness of vegetation restoration strategies.

Highlights

Desert vegetation resources are an important component of the ecosystem in arid desert areas, and they are highly significant in maintaining the stability of ecosystems and preventing desertification [1,2]
To test the above hypotheses, we selected a mixed forest sampling site consisting of P. euphratica and T. chinensis, and we investigated the water use characteristics of P. euphratica and T. chinensis at different growth stages using stable isotope techniques (δ18O and δ13C) in 2019 and 2020
Our study found that the δ13C values of P. euphratica leaves were lower than those of T. chinensis, which indicates that T. chinensis has a higher water use efficiency (WUE)

Summary

Introduction

Desert vegetation resources are an important component of the ecosystem in arid desert areas, and they are highly significant in maintaining the stability of ecosystems and preventing desertification [1,2]. Plant water use patterns are influenced by many physiological and physical characteristics [17], such as the distribution and functioning of fine roots [13], the availability of soil water [14,15], and the water demands of trees [16]. Most of these studies have focused on plant water use patterns in pure forests, and insufficient research has been conducted on the water use patterns of different vegetation types and stages of plant growth in desert riparian forests. The differences in plant water use patterns during periods of the presence or absence of river water in arid regions remain unclear

Methods

Results

Discussion

Conclusion