中文版 | English

在结果中检索

GSTDTAP

浏览/检索结果: 共9条，第1-9条 帮助

已选(0)清除 条数/页：   排序方式：
Hydrothermal (NN)-N-15-N-15 abundances constrain the origins of mantle nitrogen 期刊论文
NATURE, 2020, 580 (7803) : 367-+
作者:  Zhao, Steven;  Jang, Cholsoon;  Liu, Joyce;  Uehara, Kahealani;  Gilbert, Michael;  Izzo, Luke;  Zeng, Xianfeng;  Trefely, Sophie;  Fernandez, Sully;  Carrer, Alessandro;  Miller, Katelyn D.;  Schug, Zachary T.;  Snyder, Nathaniel W.;  Gade, Terence P.;  Titchenell, Paul M.;  Rabinowitz, Joshua D.;  Wellen, Kathryn E.
收藏  |  浏览/下载：34/0  |  提交时间：2020/05/13

Nitrogen is the main constituent of the Earth'  s atmosphere, but its provenance in the Earth'  s mantle remains uncertain. The relative contribution of primordial nitrogen inherited during the Earth'  s accretion versus that subducted from the Earth'  s surface is unclear(1-6). Here we show that the mantle may have retained remnants of such primordial nitrogen. We use the rare (NN)-N-15-N-15 isotopologue of N-2 as a new tracer of air contamination in volcanic gas effusions. By constraining air contamination in gases from Iceland, Eifel (Germany) and Yellowstone (USA), we derive estimates of mantle delta N-15 (the fractional difference in N-15/N-14 from air), N-2/Ar-36 and N-2/He-3. Our results show that negative delta N-15 values observed in gases, previously regarded as indicating a mantle origin for nitrogen(7-10), in fact represent dominantly air-derived N-2 that experienced N-15/N-14 fractionation in hydrothermal systems. Using two-component mixing models to correct for this effect, the (NN)-N-15-N-15 data allow extrapolations that characterize mantle endmember delta N-15, N-2/Ar-36 and N-2/He-3 values. We show that the Eifel region has slightly increased delta N-15 and N-2/Ar-36 values relative to estimates for the convective mantle provided by mid-ocean-ridge basalts(11), consistent with subducted nitrogen being added to the mantle source. In contrast, we find that whereas the Yellowstone plume has delta N-15 values substantially greater than that of the convective mantle, resembling surface components(12-15), its N-2/Ar-36 and N-2/He-3 ratios are indistinguishable from those of the convective mantle. This observation raises the possibility that the plume hosts a primordial component. We provide a test of the subduction hypothesis with a two-box model, describing the evolution of mantle and surface nitrogen through geological time. We show that the effect of subduction on the deep nitrogen cycle may be less important than has been suggested by previous investigations. We propose instead that high mid-ocean-ridge basalt and plume delta N-15 values may both be dominantly primordial features.


  
Denitrification as a major regional nitrogen sink in subtropical forest catchments: Evidence from multi-site dual nitrate isotopes 期刊论文
GLOBAL CHANGE BIOLOGY, 2019, 25 (5) : 1765-1778
作者:  Yu, Longfei;  Mulder, Jan;  Zhu, Jing;  Zhang, Xiaoshan;  Wang, Zhangwei;  Doersch, Peter
收藏  |  浏览/下载：14/0  |  提交时间：2019/11/26
groundwater discharge zone  hydrological continuum  isotopic modelling  nitrification  nitrogen removal  delta N-15 and delta O-18 of nitrate  
Assessing the role of native herbaceous legumes in the nitrogen cycle of regularly burned loblolly pine forests 期刊论文
FOREST ECOLOGY AND MANAGEMENT, 2019, 438: 123-133
作者:  Hendricks, Joseph J.;  Holland, J. Blake;  Hubbartt, John S.
收藏  |  浏览/下载：14/0  |  提交时间：2019/11/26
Prescribed burning  Native herbaceous legumes  Nitrogen  N-2-fixation  N-15 natural abundance  Substrate quality  Lignin  Loblolly pine forest  Piedmont ecoregion  
Postfire nitrogen balance of Mediterranean shrublands: Direct combustion losses versus gaseous and leaching losses from the postfire soil mineral nitrogen flush 期刊论文
GLOBAL CHANGE BIOLOGY, 2018, 24 (10) : 4505-4520
作者:  Dannenmann, Michael;  Diaz-Pines, Eugenio;  Kitzler, Barbara;  Karhu, Kristiina;  Tejedor, Javier;  Ambus, Per;  Parra, Antonio;  Sanchez-Martin, Laura;  Resco, Victor;  Ramirez, David A.;  Povoas-Guimaraes, Luciano;  Willibald, Georg;  Gasche, Rainer;  Zechmeister-Boltenstern, Sophie;  Kraus, David;  Castaldi, Simona;  Vallejo, Antonio;  Rubio, Agustin;  Moreno, Jose M.;  Butterbach-Bahl, Klaus
收藏  |  浏览/下载：22/0  |  提交时间：2019/04/09
N-15 isotope labelling  dinitrogen  experimental fire  Mediterranean shrubland  N leaching  nitric oxide  nitrogen leaching  nitrous oxide  postfire mineral N flush  soil-atmosphere exchange  
Elevated CO2 and water addition enhance nitrogen turnover in grassland plants with implications for temporal stability 期刊论文
ECOLOGY LETTERS, 2018, 21 (5) : 674-682
作者:  Dijkstra, Feike A.;  Carrillo, Yolima;  Blumenthal, Dana M.;  Mueller, Kevin E.;  LeCain, Dan R.;  Morgan, Jack A.;  Zelikova, Tamara J.;  Williams, David G.;  Follett, Ronald F.;  Pendall, Elise
收藏  |  浏览/下载：26/0  |  提交时间：2019/04/09
N-15 stable isotopes  global warming  grassland species  nitrogen cycling  plant uptake  pulse-chase  reallocation  resorption  semi-arid  
Fates of atmospheric deposited nitrogen in an Asian tropical primary forest 期刊论文
FOREST ECOLOGY AND MANAGEMENT, 2018, 411: 213-222
作者:  Wang, Ang;  Zhu, Weixing;  Gundersen, Per;  Phillips, Oliver L.;  Chen, Dexiang;  Fang, Yunting
收藏  |  浏览/下载：24/0  |  提交时间：2019/04/09
N-15 tracer  Nitrogen deposition  Nitrogen retention  Plant uptake  Carbon sequestration  Total ecosystem recovery  
Biomass production, nitrogen accumulation and symbiotic nitrogen fixation in a mixed-species plantation of eucalypt and acacia on a nutrient-poor tropical soil 期刊论文
FOREST ECOLOGY AND MANAGEMENT, 2017, 403
作者:  Tchichelle, Sogni Viviane;  Mareschal, Louis;  Koutika, Lydie-Stella;  Epron, Daniel
收藏  |  浏览/下载：9/0  |  提交时间：2019/04/09
N-15 isotope dilution  Competition  Facilitation  Ferralic arenosols  Biological nitrogen fixation  
Decomposition nitrogen is better retained than simulated deposition from mineral amendments in a temperate forest 期刊论文
GLOBAL CHANGE BIOLOGY, 2017, 23 (4)
作者:  Nair, Richard K. F.;  Perks, Michael P.;  Mencuccini, Maurizio
收藏  |  浏览/下载：22/0  |  提交时间：2019/04/09
N-15-nitrogen  forest  isotope trace  litter decomposition  litter nitrogen  nitrogen fertilization  
Multiyear fate of a N-15 tracer in a mixed deciduous forest: retention, redistribution, and differences by mycorrhizal association 期刊论文
GLOBAL CHANGE BIOLOGY, 2017, 23 (2)
作者:  Goodale, Christine L.
收藏  |  浏览/下载：19/0  |  提交时间：2019/04/09
N-15 tracer  arbuscular mycorrhizae  ectomycorrhizae  nitrogen deposition  nitrogen fate  nitrogen retention  nitrogen uptake