文献类型：期刊文献

英文题名：The interaction between nitrogen and phosphorous is a strong predictor of intra-plant variation in nitrogen isotope composition in a desert species

作者：Zhang, Jinxin[1,2] Gu, Lianhong[3,4] Zhang, Jingbo[1,5] Wu, Rina[1] Wang, Feng[1] Lin, Guanghui[6] Wu, Bo[1] Lu, Qi[1] Meng, Ping[7]

第一作者：张金鑫

通信作者：Gu, LH[1];Gu, LH[2]

机构：[1]Chinese Acad Forestry, Inst Desertificat Studies, Beijing, Peoples R China;[2]Chinese Acad Forestry, Res Inst Forestry, Beijing, Peoples R China;[3]Oak Ridge Natl Lab, Environm Sci Div, Oak Ridge, TN 37831 USA;[4]Oak Ridge Natl Lab, Climate Change Sci Inst, Oak Ridge, TN 37831 USA;[5]Chinese Acad Forestry, Expt Ctr Desert Forestry, Dengkou, Inner Mongolia, Peoples R China;[6]Tsinghua Univ, Ctr Earth Syst Sci, Beijing, Peoples R China;[7]Chinese Acad Forestry, Beijing, Peoples R China

年份：2017

卷号：14

期号：1

起止页码：131-144

外文期刊名：BIOGEOSCIENCES

收录：;Scopus(收录号：2-s2.0-85009251294);WOS:【SCI-EXPANDED(收录号:WOS:000393683200001)】；

基金：Field work, data acquisition, and analyses were conducted at the Institute of Desertification Studies with support from the National Key Technology R&D Program of the Ministry of Science and Technology of China (2012BAD16B01), the National Natural Science Foundation of China Youth Fund Project (31400620), the State Forestry Administration of China Forestry Public Welfare Scientific Research Funding (201404304), the Science and Technology Foundation (CAF201202), and the Lecture and Study Program for Outstanding Scholars from Home and Abroad of the Chinese Academy of Forestry (CAFYBB2011007). Data analyses and manuscript writing were partly carried out at Oak Ridge National Laboratory (ORNL) with support from US Department of Energy, Office of Science, Biological and Environmental Research Program, Climate and Environmental Sciences Division. ORNL is managed by UT-Battelle, LLC, for the US Department of Energy under contract DE-AC05-00OR22725.

语种：英文

摘要：Understanding intra-plant variations in delta N-15 is essential for fully utilizing the potential of delta N-15 as an integrator of the terrestrial nitrogen (N) cycle and as an indicator of the relative limitation of N and phosphorous (P) on plant growth. Studying such variations can also yield insights into N metabolism by plant as a whole or by specific organs. However, few researchers have systematically evaluated intra-plant variations in delta N-15 and their relationships with organ nutrient contents. We excavated whole plant architectures of Nitraria tangutorum Bobrov, a C-3 species of vital regional ecological importance, in two deserts in northwestern China. We systematically and simultaneously measured N isotope ratios and N and P contents of different parts of the excavated plants. We found that intra-plant variations in delta N-15 of N. tangutorum were positively correlated with corresponding organ N and P contents. However, it was the N x P interaction, not N and P individually or their linear combination, that was the strongest predictor of intra-plant delta N-15. Additionally, we showed that root delta N-15 increased with depth into soil, a pattern similar to profiles of soil delta N-15 reported by previous studies in different ecosystems. We hypothesized that the strong positive intra-plant delta N-15-N and P relationships are caused by three processes acting in conjunction: (1) N and P content-driven fractionating exchanges of ammonia between leaves and the atmosphere (volatilization) during photorespiration, (2) resorption and remobilization of N and P from senescing leaves, and (3) mixture of the re-translocated foliar N and P with existing pools in stems and roots. To test our hypothesis, future studies should investigate plant N volatilization and associated isotope fractionation and intra-plant variations in delta N-15 in different species across ecosystems and climates.