| 引用本文: | 王炫臻,段义忠,王紫薇,裴艳武,黄来明,张萍萍.2026.陕北风沙区固沙植物长梗扁桃根系吸水来源及其影响因素[J].地球环境学报,17(3):659-668 |
| WANG Xuanzhen,DUAN Yizhong,WANG Ziwei,PEI Yanwu,HUANG Laiming,ZHANG Pingping.2026.Root water sources of Prunus pedunculata and their influencing factors in the wind-sandy area of Northern Shaanxi Province[J].Journal of Earth Environment,17(3):659-668 |
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| 陕北风沙区固沙植物长梗扁桃根系吸水来源及其影响因素 |
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王炫臻1，段义忠2，王紫薇3，裴艳武2，黄来明1，4，5，张萍萍4
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1. 中国科学院地理科学与资源研究所 现代农业工程实验室, 北京 100101 ；2. 榆林学院研究生院, 榆林 719000 ；3. 西北农林科技大学 资源环境学院, 杨凌 712100 ；4. 中国科学院地球环境研究所 黄土科学全国重点实验室, 西安 710061 ；5. 中国科学院大学 资源与环境学院, 北京 100049
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| 摘要: |
| 水资源对维持陕北风沙区生态平衡和植被可持续建设至关重要, 揭示陕北风沙区固沙植物根系吸水来源及其影响因素可为该地区植被建设和水资源合理利用提供科学依据。文章选取陕北风沙区典型固沙植物长梗扁桃(Prunus pedunculata), 于2019—2021年生长季(5—10月)每月定期采集并测定植物木质部水及其潜在水源(不同深度土壤水和地下水)的δD和δ18O, 共采集植物木质部水样品54个、土壤水样品324个(0—200 cm分6层)、地下水样品54个, 降水样品每次降雨后采集(生长季内共采集53次), 分别分析各水体氢氧同位素组分变化特征。在此基础上, 根据同位素质量平衡原理, 结合MixSIAR模型研究长梗扁桃根系吸水来源及影响因素。结果表明: 生长季内长梗扁桃木质部水、土壤水和地下水的δD值变化范围分别为-91.96‰——-44.72‰、-91.80‰——-30.29‰和-63.30‰——-58.35‰, δ18O值变化范围分别为-12.74‰——-6.35‰、-15.06‰——-2.21‰和-8.58‰——-7.84‰。2019—2021年雨季(7—9月)平均降雨量和地下水位分别高于旱季(5月、6月和10月)25.61%和3.35%。旱季长梗扁桃主要利用活跃层(0—60 cm)和近饱和层(140—200 cm)土壤水(59.39%±11.99%), 雨季则主要利用活跃层(0—60 cm)和稳定层(60—140 cm)土壤水(64.43%±2.85%)。活跃层水分对长梗扁桃根系吸水的贡献率与月累积降水量、细根生物量占比呈显著正相关(p<0.01), 但与地下水位埋深呈显著负相关(p<0.05)。降水季节性变化、细根生物量占比以及地下水位周期性波动是影响长梗扁桃根系吸水活跃土层的主控因子。 |
| 关键词: 黄土高原北部 长梗扁桃 根系吸水 稳定同位素 地下水 |
| DOI：10.7515/JEE2024104 |
| CSTR：32259.14.JEE2024104 |
| 分类号: |
| 基金项目:国家自然科学基金项目（42377302）；黄土与第四纪地质国家重点实验室开放基金项目（SKLLQG2334） |
| 英文基金项目: |
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| Root water sources of Prunus pedunculata and their influencing factors in the wind-sandy area of Northern Shaanxi Province |
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WANG Xuanzhen1，DUAN Yizhong2，WANG Ziwei3，PEI Yanwu2，HUANG Laiming1，4，5，ZHANG Pingping4
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1. Modern Agricultural Engineering Laboratory, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 , China ；2. Graduate School, Yulin University, Yulin 719000 , China ；3. College of Natural Resources and Environment, Northwest A & F University, Yangling 712100 , China ；4. State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061 , China ；5. College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049 , China
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| Abstract: |
| Background, aim, and scope Water resources are crucial for maintaining the ecological balance and supporting sustainable vegetation construction in the wind-blown sand area of Northern Shaanxi Province. Revealing the water uptake sources of sand-fixing plants and their influencing factors in this region can provide a scientific basis for vegetation construction and rational water resource utilization. While previous studies have examined plant water uptake sources in different regions, little is known about the water sources of typical sand-fixing plants under conditions of seasonal drought and periodic groundwater fluctuation in the wind-blown sand regions of Northern Shaanxi Province. This paper analyzed the root water uptake patterns of a typical sand-fixing plant (Prunus pedunculata) and their influencing factors in the wind-blown sand area of Northern Shaanxi Province. The aims of this study were to (1) determine the variation in isotopic composition among different water potential sources, (2) quantify the relative contributions of these water sources to the plant, and (3) identify the key drivers controlling root water uptake. Materials and methods The study area (38°48′—38°54′N, 109°11′—109°29′E) is located in the Gechougou small watershed of Yulin City, Northern Shaanxi Province. During the growing seasons (May to October) from 2019 to 2021, plant xylem water and its potential water sources (soil water at different depths and groundwater) were collected and measured monthly for δD and δ18O, and a total of 324 soil water samples were collected from six depths (0—20 cm, 20—40 cm, 40—60 cm, 60—90 cm, 90—140 cm, and 140—200 cm), along with 54 xylem water samples and 54 groundwater samples. Precipitation samples were collected after each rainfall event during the growing seasons, and 53 precipitation samples were collected in total. The variation characteristics of hydrogen and oxygen isotope compositions examined. Based on the principle of isotope mass balance and using the MixSIAR model, the sources and influencing factors of root water uptake in P. pedunculata were further investigated. Results The results showed that during the growing season, the δD values of xylem water, soil water and groundwater were in the range of -91.96‰——-44.72‰, -91.80‰——-30.29‰ and -63.30‰——-58.35‰, respectively. The corresponding δ18O values were in the range of -12.74‰——-6.35‰, -15.06‰——-2.21‰ and -8.58‰——-7.84‰, respectively. The average rainfall amount and groundwater level during the rainy season (July to September) were 25.61% and 3.35% higher than those during the dry season (May, June and October), respectively. During the dry season, P. pedunculata mainly absorbed soil water from the active layer (0—60 cm) and moist layer (140—200 cm), accounting for 59.39%±11.99% of total uptake. In contrast, during the rainy season, P. pedunculata mainly relied on soil water from the active layer (0—60 cm) and stable layer (60—140 cm), constituting 64.43%±2.85% of total uptake. The contribution of active layer water to root water uptake was significantly positively correlated with monthly cumulative precipitation and the proportion of fine root biomass (p<0.01), but significantly negatively correlated with groundwater table depth (p<0.05). Discussion The clear seasonal shift in water sources demonstrates the high plasticity of P. pedunculata's root system in response to changing water availability. During the dry season, the depletion of shallow soil moisture forces the plant to rely on deeper, more stable water sources. The significant positive correlation between the contribution from the active layer and monthly cumulative precipitation, and the significant negative correlation with groundwater table depth, indicate that rainfall replenishment and groundwater level fluctuations are key environmental controls. Moreover, the strong positive correlation between active layer water contribution and the proportion of fine root biomass in that layer (which accounted for 60.9% of total fine roots) provides direct evidence that root distribution is a major biological factor determining water uptake depth. Conclusions During the dry season, P. pedunculata primarily relied on soil water at depths of 60—200 cm, whereas in the rainy season, it mainly drew from soil water with the 0—140 cm layer. The contribution of active layer water to root uptake in P. pedunculata showed a significant positive correlation with monthly cumulative precipitation and the proportion of fine root biomass (p<0.01), and a significant negative correlation with groundwater table depth (p<0.05). Seasonal precipitation variation, fine root biomass proportion, and periodic fluctuations in groundwater level were identified as the principal factors influencing root water uptake from the active soil layer. Recommendations and perspectives This study offers useful insights for informing rational vegetation restoration practices in the wind-blown sand areas of Northern Shaanxi Province, and can support the formulation of management strategies and policies aimed at achieving sustainable development goals. |
| Key words: northern Chinese Loess Plateau Prunus pedunculata root uptake stable isotope groundwater |
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