Results 31 to 40 of about 128,824 (253)

Nitrogen Isotopes in Deep Time [PDF]

, 2021
Nitrogen is an essential nutrient for life, and its sources and cycling have varied over earth history. Stable isotope ratios of nitrogen compounds (expressed as δ15N, in ‰) are preserved in the sedimentary record and track these changes, providing important insights into associated biogeochemical feedbacks.
Mettam, Colin, Zerkle, Aubrey L.
openaire   +2 more sources

Evapotranspiration and water use efficiency in relation to climate and canopy nitrogen in U.S. forests [PDF]

, 2016
Understanding relations among forest carbon (C) uptake and water use is critical for predicting forest-climate interactions. Although the basic properties of tree-water relations have long been known, our understanding of broader-scale patterns is ...
Anav, Atkin, Badeck, Baldocchi, Baldocchi, Baldocchi, Baldocchi, Baldocchi, Barbour, Barbour, Barbour, Barnard, Beer, Belmecheri, Berry, Betts, Bolster, Bonan, Bonan, Bright, Brugnoli, Buckley, Canadell, Carnicer, Catovsky, Cernusak, Chen, Clark, Craig, Davin, Desai, Dickinson, Dongmann, Donovan, Dore, Evans, Ewers, Farquhar, Farquhar, Farquhar, Farquhar, Farquhar, Federer, Fernández-Martínez, Fernández-Martínez, Flanagan, Flexas, Gessler, Gessler, Grams, Grassi, Guerrieri, Heimann, Jennings, Keenan, Keitel, Kergoat, Kunert, Law, Lee, Leonelli, Lepine, Liang, Loescher, Luyssaert, Lévesque, Magnani, Martin, Martínez-Vilalta, Meinzer, Meir, Michelot, Moffat, Monson, Moreno-Gutiérrez, Niinemets, Niu, Ollinger, Ollinger, Pan, Pan, Papale, Paquette, Ponton, Post, Potter, Powell, Reichstein, Reichstein, Renninger, Richardson, Ripullone, Roden, Roden, Roden, Roman, Sage, Scartazza, Scheidegger, Schulze, Seibt, Siegwolf, Smith, Smith, Song, Sullivan, Tang, Tang, Tardieu, Valentini, Valentini, Wang, Warren, Wehr, Wright, Xiao, Xiao, Xu, Zhang, Zhu   +119 more
core   +3 more sources

Elementary Isotopic Analysis: Determination of Nitrogen [PDF]

Nature, 1947
We have recently described an isotopic method for the determination of oxygen1 and carbon2 in organic compounds by using heavy oxygen (O18) and carbon (C13) respectively in conjunction with a mass spectrometer. Using the same method, higher precision is possible in the determination of nitrogen and hydrogen, since N15 and H2 (deuterium) are available ...
A D, KIRSHENBAUM, S G, HINDIN, A V, GROSSE   +2 more
openaire   +2 more sources

Different Responses in Root Water Uptake of Summer Maize to Planting Density and Nitrogen Fertilization

Frontiers in Plant Science, 2022
Modifying farming practices combined with breeding has the potential to improve water and nutrient use efficiency by regulating root growth, but achieving this goal requires phenotyping the roots, including their architecture and ability to take up water
Yang Gao, Jinsai Chen, Guangshuai Wang, Zhandong Liu, Weihao Sun, Yingying Zhang, Xiaoxian Zhang   +6 more
doaj   +1 more source

Reactive and mixing processes governing ammonium and nitrate coexistence in a polluted coastal aquifer [PDF]

, 2018
A comprehensive hydrochemical, stable isotope and microbial analyses characterisation has been performed to evaluate the sources of groundwater, nitrogen pollution and degradation processes occurring in an industrial polluted coastal aquifer in the ...
Aravena, Ramon, Colombani, Nicolò, Mastrocicco, Micòl, Petitta, Marco, Sbarbati, Chiara   +4 more
core   +2 more sources

The transition zone as a host for recycled volatiles: Evidence from nitrogen and carbon isotopes in ultra-deep diamonds from Monastery and Jagersfontein (South Africa) [PDF]

, 2017
Sublithospheric (ultra-deep) diamonds provide a unique window into the deepest parts of Earth's mantle, which otherwise remain inaccessible. Here, we report the first combined C- and N-isotopic data for diamonds from the Monastery and Jagersfontein ...
Gurney, J.J., Harris, J.W., Le Pioufle, A., Palot, M., Pearson, D.G., Stachel, T., Stern, R.A.   +6 more
core   +1 more source

The fate of nitrogen in the Zarin-Gol River receiving trout farm effluent

Scientific Reports, 2023
This study investigated the Zarrin-Gol River ecosystem in Iran to trace organic matter in the food web and evaluate the impact of aquaculture farm effluent using stable isotopes of nitrogen (δ15N) and carbon (δ13C).
Altin Ghojoghi, Rasoul Ghorbani, Rahman Patimar, Abdolrassoul Salmanmahiny, Rahmat Naddafi, Abdolazim Fazel, Timothy D. Jardine   +6 more
doaj   +1 more source

Nitrogen isotopic analyses by isotope-ratio-monitoring gas chromatography / mass spectrometry [PDF]

Journal of the American Society for Mass Spectrometry, 1994
Amino acids containing natural-abundance levels of 15N were derivatized and analyzed isotopically using a technique in which individual compounds are separated by gas chromatography, combusted on-line, and the product stream sent directly to an isotope-ratio mass spectrometer. For samples of N2 gas, standard deviations of ratio measurement were better
Merritt, Dawn A., Hayes, J.M.
openaire   +3 more sources

Tree growth acceleration and expansion of alpine forests: The synergistic effect of atmospheric and edaphic change. [PDF]

, 2016
Many forest ecosystems have experienced recent declines in productivity; however, in some alpine regions, tree growth and forest expansion are increasing at marked rates.
Horwath, William R, Liang, Qianlong, Silva, Lucas CR, Sun, Geng, Wu, Ning, Zhu-Barker, Xia   +5 more
core   +2 more sources

Tooth enamel nitrogen isotope composition records trophic position: a tool for reconstructing food webs

Communications Biology, 2023
Enamel-bound nitrogen isotopes in modern and fossil mammal teeth preserve dietary and trophic level information. This novel geochemical archive can be used to reconstruct trophic niche in ancient ecosystems.
Jennifer N. Leichliter, Tina Lüdecke, Alan D. Foreman, Nicolas Bourgon, Nicolas N. Duprey, Hubert Vonhof, Viengkeo Souksavatdy, Anne-Marie Bacon, Daniel M. Sigman, Thomas Tütken, Alfredo Martínez-García   +10 more
doaj   +1 more source