Patterns and drivers of seasonal water sources for artificial sand-fixing plants in the northeastern Mu Us sandy land,Northwest China  

作　　者：Yanwu PEI Laiming HUANG Ming'an SHAO Jiao WANG Yinglong ZHANG 

机构地区：[1]Yellow River Delta Modern Agricultural Engineering Laboratory,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China [2]College of Natural Resources and Environment,Northwest Agriculture and Forestry University,Yangling 712100,China [3]State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences of Chinese Academy of Sciences,Beijing 100085,China [4]College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China [5]Shenmu Ecological Association,Shenmu 719399,China

出　　处：《Pedosphere》2024年第1期63-77,共15页土壤圈（英文版）

基　　金：funded by the National Natural Science Foundation of China(No.42377302);the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2019052);the Bingwei Outstanding Young Talent Project from the Institute of Geographical Sciences and Natural Resources Research,China(2017RC203);the Open Foundation of State Key Laboratory of Urban and Regional Ecology,China(SKLURE2023-2-2)。

摘　　要：Understanding plant water-use patterns is important for improving water-use efficiency and for sustainable vegetation restoration in arid and semi-arid regions. However, seasonal variations in water sources and their control by different sand-fixing plants in water-limited desert ecosystems remain poorly understood. In this study, stable isotopic ratios of hydrogen(δ^(2)H) and oxygen(δ^(18)O) in precipitation, soil water, groundwater, and xylem water were determined to document seasonal changes in water uptake by three representative plant species(Pinus sylvestris var. mongolica Litv., Amygdalus pedunculata Pall., and Salix psammophila) in the northeastern Mu Us sandy land, Northwest China. Based on the depth distribution and temporal variation of measured gravimetric soil water content(SWC), the soil water profile of the three species stands was divided into active(0.01 g g^(-1)< SWC < 0.08 g g^(-1), 20%< coefficient of variation(CV) < 45%), stable(0.02 g g^(-1)< SWC < 0.05 g g^(-1), CV < 20%), and moist(0.08 g g^(-1)< SWC < 0.20 g g^(-1), CV >45%) layers. Annually, P. sylvestris, A. pedunculata, and S. psammophila obtained most water from deep(59.2%±9.7%, moist layer and groundwater),intermediate(57.4%±9.8%, stable and moist layers), and shallow(54.4%±10.5%, active and stable layers) sources, respectively. Seasonally, the three plant species absorbed more than 60% of their total water uptake from the moist layer and groundwater in the early(June) dry season;then, they switched to the active and stable layers in the rainy season(July–September) for water resources(50.1%–62.5%). In the late(October–November) dry season, P. sylvestris(54.5%–66.2%) and A. pedunculata(52.9%–63.6%) mainly used water from stable and moist layers, whereas S. psammophila(52.6%–70.7%) still extracted water predominantly from active and stable layers. Variations in the soil water profile induced by seasonal fluctuations in precipitation and groundwater levels and discrepancies in plant phenology, root distribution, and wa

关 键 词：desert ecosystem MixSIAR model plant water uptake soil moisture stable isotopes vegetation restoration water-use efficiency 

分 类 号：Q948[生物学—植物学]