Arid Zone Research ›› 2022, Vol. 39 ›› Issue (2): 551-559.doi: 10.13866/j.azr.2022.02.22

• Plant and Plant Physiology • Previous Articles     Next Articles

Stoichiometric characteristics of leaves and fine roots in Alhagi sparsifolia in response to the addition of nitrogen and water

YU Yang1,2,3,4(),ZHANG Zhihao1,2,3,YANG Jianming5,CHAI Xutian1,2,3,4,ZENG Fanjiang1,2,3()   

  1. 1. Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China
    2. State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China
    3. Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele 848300, Xinjiang, China
    4. University of Chinese Academy of Sciences, Beijing 100049, China
    5. Ecological Protection and Restoration Division of Forestry and Grassland Bureau of Xinjiang Uygur Autonomous Region, Urumqi 830011, Xinjiang, China
  • Received:2021-07-16 Revised:2021-12-23 Online:2022-03-15 Published:2022-03-30
  • Contact: Fanjiang ZENG E-mail:2636173006@qq.com;zengfj@ms.xjb.ac.cn

Abstract:

Nitrogen and water are important factors affecting the growth of desert plants; nitrogen deposition and drought, the main driving factors of global climate change, will directly change the availability of these two resources in soil. Presently, our understanding of how N deposition and drought affect the chemometric characteristics of desert plants remains limited. Thus, a pot experiment was conducted on 1-year-old seedlings of Alhagi sparsifolia, a dominant plant of the southern edge of the Taklamakan Desert. Different amounts of N fertilizer and water were added to simulate different levels of the N deposition rate (0, 3.0, 6.0, and 9.0 g·m-2·a-1) and water conditions (drought or well-watered conditions) to explore the effects of these two factors on the stoichiometric characteristics of the leaves and fine roots of A. sparsifolia. The results show the following: (1) N and water addition independently or interactively affected the nutrient status of leaves and fine roots of A. sparsifolia, except for P content in leaves. Nitrogen addition significantly decreased the contents of N, Mn, Zn, and Cu in leaves under drought conditions but increased the absorption of these elements by fine roots to a certain extent; (2) microelements such as Mn, Zn, Cu, and Fe were enriched in the fine roots of A. sparsifolia, but macroelements such as N, P, and K were more distributed in the leaves; (3) applying 3.0 g·m-2·a-1 N under drought stress and adding 6.0 or 9.0 g·m-2·a-1 N under well-watered conditions can significantly alleviate the N limitation of fine roots of A. sparsifolia (N:P<14); (4) the nutrient elements of leaves and fine roots of A. sparsifolia have complex interactions within and between organs. The occurrence rate of this relationship between organs is greater than that within organs, followed by that in fine roots, and the lowest in leaves. These results show that A. sparsifolia can coordinate the relationship between aboveground and underground nutrients under the background of fluctuations in environmental resources. Exogenous N input can improve the nutrient status of fine roots of A. sparsifolia. These results provide further scientific reference for the efficient nutrient management and restoration of desert vegetation.

Key words: Alhagi sparsifolia, nitrogen and water, desert plants, nitrogen deposition, leaves and fine roots, stoichiometric characteristics, nutrient status