Water Use Characteristics of Two Dominant Species in the Mega-Dunes of the Badain Jaran Desert

Jie Qin,Xiaohui He,Chunyan Zhao,Jianhua Si,Xinglin Zhu,Bing Jia,Dongmeng Zhou,Chunlin Wang

doi:10.3390/w14010053

Abstract

The sparse natural vegetation develops special water use characteristics to adapt to inhospitable desert areas. The water use characteristics of such plants in desert areas are not yet completely understood. In this study, we compare the differences in water use characteristics between two dominant species of the Badain Jaran Desert mega-dunes—Zygophyllum xanthoxylum and Artemisia ordosica—by investigating δ2H and δ18O in plant xylem (the organization that transports water and inorganic salts in plant stems) and soil water, and δ13C in plant leaves. The results indicate that Z. xanthoxylum absorbed 86.5% of its water from soil layers below 90 cm during growing seasons, while A. ordosica derived 79.90% of its water from the 0–120 cm soil layers during growing seasons. Furthermore, the long-term leaf-level water use efficiency of A. ordosica (123.17 ± 2.13 μmol/mol) was higher than that of Z. xanthoxylum (97.36 ± 1.16 μmol/mol). The differences in water use between the two studied species were mainly found to relate to their root distribution characteristics. A better understanding of the water use characteristics of plants in desert habitats can provide a theoretical basis to assist in the selection of species for artificial vegetation restoration in arid areas.

Highlights

Academic Editor: Carmen TeodosiuThe Badain Jaran Desert is home to the highest mega-dunes in the world, with sparse rainfall, an arid climate, barren soil, and strong wind and sand activity
Z. xanthoxylum absorbed most of its water (86.5%) from below 90 cm soil layers, while A. ordosica derived most of its water (79.90%) from 0~120 soil layers
To better understand the water use characteristics of the two dominate species of the mega-dunes of the Badain Jaran Desert—Z. xanthoxylum and A. ordosica—we measured the δ2 H and δ18 O of plant xylem and soil water from various layers up to 240 cm under the dry sand layer and, in combination with the Iso-source model, analyzed plant water sources and the δ13 C of plant leaves to explore the interspecific differences in leaf-level

Summary

Introduction

Academic Editor: Carmen TeodosiuThe Badain Jaran Desert is home to the highest mega-dunes in the world, with sparse rainfall, an arid climate, barren soil, and strong wind and sand activity. A. ordosica represent the most dominant species and play an important role in preventing wind erosion and fixing sand These plants are distributed 100–250 m above the lake surface; as such, it is difficult for them to use groundwater directly. Due to the extreme aridity of the desert—with an average annual rainfall of just 80 mm—the question of how these plants access and use water to survive in such an extreme environment remains.

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