Water uptake sources of differently aged Populus euphratica in the lower Tarim river under ecological water conveyance

作者：Xiaoqing Jiang, Shuai Hao, Mao Ye, Dingxin He, Guohua Li, Zihan Zhang, Zhongli Feng · 发表于：Scientific Reports · 年份：2025 · DOI：10.1038/s41598-025-24001-y · 被引用次数：1 · 研究领域：Plant Water Relations and Carbon Dynamics、Hydrology and Watershed Management Studies、Tree-ring climate responses

The water use of desert vegetation is a critical component of ecohydrological processes in arid regions, with groundwater and soil water serving as the primary moisture sources. To better understand the effects of ecological water conveyance on the water sources of desert vegetation, this study employed hydrogen and oxygen stable isotope techniques combined with the Bayesian mixing (MixSIAR) model to analyze changes in water uptake sources of Populus euphratica (of different ages) under varying groundwater depths during ecological water conveyance and non-conveyance periods. The results indicate: (1) The δ 18 O and δ 2 H values of soil water decreased during the water conveyance period compared to the non-conveyance period, gradually increased with distance from the riverbank, and decreased with soil depth. The δ 18 O and δ 2 H values of xylem water increased during the water conveyance period, with the highest values observed in young trees, followed by mature trees, and the lowest in intermediate-aged trees. The δ 18 O and δ 2 H values of groundwater decreased during the water conveyance period and declined with increasing distance from the riverbank. (2) During the water conveyance period (groundwater depth: 1.95–4.73 m), the primary water sources for P. euphratica of different ages were groundwater, river water, and deep soil water, with the maximum utilization proportion of groundwater reaching 23.1%. During the non-conveyance period (groundwater depth: 4.13–6.26 m), the...