首页 | 本学科首页   官方微博 | 高级检索  
     


Divergent patterns of foliar δ13C and δ15N in Quercus aquifolioides with an altitudinal transect on the Tibetan Plateau: an integrated study based on multiple key leaf functional traits
Authors:Litong Chen  Dan F. B. Flynn  Xiaowei Zhang  Xianliang Gao  Ling Lin  Jian Luo  Changming Zhao
Affiliation:1. State Key Laboratory of Grassland Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou 730000, Gansu, China;2. Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, Qinghai, China;3. College of Tibet Agriculture and Animal Husbandry, Tibetan University, Nyingchi 860000, Tibet, China
Abstract:Aims With a close association with plant water availability, foliar δ 13 C had been investigated extensively in alpine regions; however, foliar δ 15 N has rarely been concurrently used as an indicator of plant nitrogen availability. Due to the positive correlations between leaf nitrogen content and foliar δ 13 C and δ 15 N found in previous studies, we expected that they should show consistent patterns along an altitudinal gradient.Methods To test our hypothesis, we measured foliar δ 13 C and δ 15 N in conjunction with multiple key leaf functional traits of Quercus aquifolioides, a dominant species of alpine forest on the eastern slopes of the Sygera Mountains, southeastern Tibetan Plateau from 2500 to 3800 m.Important findings (i) Contrary to our hypothesis, foliar δ 13 C exhibited a significant positive linear relationship with altitude; in contrast, foliar δ 15 N initially increased and subsequently decreased with altitude, the change in trend occurring around 3300 m. (ii) Our analyses indicated that leaf internal resistance and stomatal conductance, rather than photosynthetic capacity indicated by leaf N concentration, apparently explained the altitudinal variation in foliar δ 13 C, while differences in foliar δ 15 N were likely the result of soil N availability. (iii) Principal component analysis revealed a clear association between δ 13 C and a tradeoff between water loss and carbon gain, indicated by traits related to gas exchange such as leaf thickness, density, stomatal properties. In contrast, the second axis was associated with δ 15 N and nitrogen acquisition strategy in Q. aquifolioides across its altitudinal distribution, represented by traits related to nitrogen concentration and stomata per gram of leaf nitrogen.
Keywords:elevation  carbon and nitrogen isotopes  leaf internal resistance  leaf mass per unit area (LMA)  stomatal conductance  trade-off  
点击此处可从《Journal of Plant Ecology》浏览原始摘要信息
点击此处可从《Journal of Plant Ecology》下载全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号