文献类型：期刊文献

英文题名：Species-specific and seasonally dynamic δD offsets in a walnut-alfalfa intercropping system: unraveling the role of climatic and soil moisture drivers

作者：Wang, Yao[1,2,3] Zhang, Jinsong[1,2,3] He, Chunxia[1,2,3] Meng, Ping[1,2,3] Wang, Jie[4] Sang, Yuqiang[5] Xue, Pan[6] Cai, Jinfeng[2] Lu, Sen[1,2,3]

第一作者：Wang, Yao;王雁

通信作者：He, CX[1]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, Natl Forestry & Grassland Adm, Key Lab Tree Breeding & Cultivat, Beijing 100091, Peoples R China;[2]Nanjing Forest Univ, Collaborat Innovat Ctr Sustainable Forestry Southe, Nanjing 210037, Jiangsu, Peoples R China;[3]Henan Xiaolangdi Forest Ecosyst Natl Observat & Re, Jiyuan 454650, Peoples R China;[4]Acad Forestry Inventory & Planning, State Forestry & Grassland Adm, Beijing 100714, Peoples R China;[5]Henan Agr Univ, Coll Forestry, Zhengzhou 450046, Henan, Peoples R China;[6]Jiyuan Forestry Bur, Jiyuan 454650, Peoples R China

年份：2026

卷号：231

外文期刊名：PLANT PHYSIOLOGY AND BIOCHEMISTRY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001650464700001)】；

基金：Funding This work is supported by National Key R & D Program of China (2022YFD1000100) and Fundamental Research Funds for the Central Non-profit Research Institution of CAF (grant number CAFYBB2020SY001) . In addition, the study is also supported by a grant from the Key Technologies Research and Development in Henan Prov-ince (232102110063) .

语种：英文

外文关键词：Isotopic offsets; seasonal variation; SW-Excess equation; Climatic sensitivity

摘要：Growing evidence has revealed SD offsets in soil-plant water systems, contradicting the long-held hypothesis of isotopic non-fractionation during plant water absorption. We aimed to determine whether SD offsets exist for plants in walnut (Juglans regia L.)-alfalfa (Medicago sativa L.) intercropping system and to explore the effects of intercropping and plant species on SD offsets. We conducted an analysis of the isotopic signatures of soil and plant water, calculated SD offsets utilizing the soil water excess (SW-excess) equation across varying seasons from 2021 to 2023 in walnut-alfalfa intercropping, monocropping walnut, and monocropping alfalfa systems. The findings revealed that all plant systems exhibited SD offsets with distinct seasonal variations. Specifically, walnuts and alfalfa displayed noteworthy positive SD offsets during dry-1 season (1.43 and 2.98 %o) and substantial negative SD offsets during the rainy season (-8.80 and-12.25 %o). Additionally, walnut exhibited negative SD offsets (-7.53 %o) in dry-2 season, while alfalfa showed no SD offsets. The SD offset patterns in intercropped and monocropped plants remained consistent across different seasons, with no significant disparities between them. Correlation analyses indicated that walnut SD offsets were negatively associated with air humidity and soil moisture content, yet positively correlated with saturated vapor pressure difference; whereas, alfalfa SD offsets were notably negatively correlated with air temperature and relative humidity. Our findings suggest that SD offset may be a prevalent phenomenon, unaffected by intercropping patterns but significantly influenced by plant species. Compared to walnuts, alfalfa displayed higher sensitivity to climatic factors, resulting in a more pronounced offset magnitude.