热带亚热带植物学报2025，Vol.33Issue(5)：495-502,8.DOI:10.11926/jtsb.4994
哀牢山亚热带森林附生维管植物δ15N特征及分馏效应
δ15N Characteristics and 15N Fractionation Effects of Vascular Epiphytes in Subtropical Forests of Ailao Mountains
摘要
Abstract
The natural variation of nitrogen(N)isotope composition(δ15N)in leaves has been used to study the N acquisition and utilization strategies of epiphytic vascular plants.However,the 15N fractionation effect that occurs during N absorption,transport,and assimilation in plants often affects the reliability of research results based on the 15N natural abundance method.Whether 15N fractionation occurs in epiphytic plants and leads to δ15N differences among different organs,as well as whether leaf δ15N can be used as a reliable proxy for whole-plant δ15N,remains unclear.This study took epiphytic plants in the subtropical evergreen broad-leaved forest of Ailao Mountain as the research object,analyzed the δ15N variation characteristics of the whole plant and each organ,and the relationship between the δ15N difference among organs and other traits.The results showed that the δ15N of leaves(-3.48‰),stems(-3.47‰),and roots(-2.25‰)of epiphytic plants were all negative,indicating that they mainly relied on 15N-depleted N sources from atmospheric deposition.Except for Oreocharis longifolia,the other epiphytic plants(Cautleya gracilis,Lepisorus scolopendrium,and Pleione hookeriana)showed N isotope fractionation effects among leaves,stems,and roots(leaf-root:-1.23‰,leaf-stem:-0.62‰,stem-root:-1.10‰),but usually lower than those of terrestrial plants.In addition,the leaf-root 15N fractionation value of epiphytic plants was significantly negatively correlated with leaf δ13C(r=-0.57;P<0.01)and root δ13C(r=-0.57,-0.50;P<0.05),which may imply their high sensitivity to water deficiency.The δ15N of epiphytic vascular plant leaves was significantly correlated with whole-plant δ15N(R2adj.=0.526,P<0.01),confirming that leaf δ15N can be used as a proxy for whole-plant δ15N.This provides an important basis for using leaf δ15N to explore the N acquisition strategies and ecological adaptation mechanisms of epiphytic plants.关键词
附生维管植物/亚热带森林/氮同位素自然丰度(δ15N)/15N分馏/N营养/水分胁迫Key words
Vascular epiphytes/Subtropical forest/Natural abundance of nitrogen isotopes(δ15N)/15N fractionation/N nutrient/Water stress引用本文复制引用
周春艳,苏天昊,刘彦,普晓妍,鲁志云,李苏..哀牢山亚热带森林附生维管植物δ15N特征及分馏效应[J].热带亚热带植物学报,2025,33(5):495-502,8.基金项目
国家自然科学基金项目(32171554,32471641) （32171554,32471641）
云南省高层次人才培养支持计划青年拔尖人才专项(YNWR-QNBJ-2020-067)资助 This work was supported by the National Natural Science Foundation of China(Grant No.32171554,32471641),and the Yunnan Revitalization Talent Support Program(Grant No.YNWR-QNBJ-2020-067). （YNWR-QNBJ-2020-067）
