Contrasting δ15N Values of Atmospheric Deposition and Sphagnum Peat Bogs: N Fixation as a Possible Cause

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F16%3A00000259" target="_blank" >RIV/00025798:_____/16:00000259 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/16:10328913

Výsledek na webu

<a href="http://link.springer.com/article/10.1007/s10021-016-9985-y?wt_mc=Internal.Event.1.SEM.ArticleAuthorAssignedToIssue" target="_blank" >http://link.springer.com/article/10.1007/s10021-016-9985-y?wt_mc=Internal.Event.1.SEM.ArticleAuthorAssignedToIssue</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s10021-016-9985-y" target="_blank" >10.1007/s10021-016-9985-y</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Contrasting δ15N Values of Atmospheric Deposition and Sphagnum Peat Bogs: N Fixation as a Possible Cause

Popis výsledku v původním jazyce

Nitrogen (N) isotope systematics were investigated at two high-elevation ombrotrophic peat bogs polluted by farming and heavy industry. Our objective was to identify N sources and sinks for isotope mass balance considerations. For the first time, we present a time-series of d15N values of atmospheric input at the same locations as d15N values of living Sphagnum and peat. The mean d15N values systematically increased in the order: input NH4+ (-10.0 per mil) < input NO3- (-7.9 per mil) < peat porewater (-5.6 per mil) < Sphagnum (-5.0 per mil) < shallow peat (-4.2 per mil) < deep peat (-2.2 per mil) < runoff (-1.4 per mil) < porewater N2O (1.4 per mil). Surprisingly, N of Sphagnum was isotopically heavier than N of the atmospheric input (P < 0.001). If partial incorporation of reactive N from the atmosphere into Sphagnum was isotopically selective, the residual N would have to be isotopically extremely light. Such N, however, was not identified anywhere in the ecosystem. Alternatively, Sphagnum may have contained an admixture of isotopically heavier N. Ambient air contains such N in the form of N2 (d15N-N2 = 0 per mil). Because high energy is required to break the triple bond, microbial N fixation is likely to proceed only under limited availability of pollutant N. Also for the first time, a d15N comparison is presented between anoxic deeper peat and porewater N2O. Isotopically light N is removed from anoxic substrate by denitrification, whose final product, N2, escapes into the atmosphere. Porewater N2O is an isotopically heavy residuum following partial N2O reduction to N2.

Název v anglickém jazyce

Contrasting δ15N Values of Atmospheric Deposition and Sphagnum Peat Bogs: N Fixation as a Possible Cause

Popis výsledku anglicky

Nitrogen (N) isotope systematics were investigated at two high-elevation ombrotrophic peat bogs polluted by farming and heavy industry. Our objective was to identify N sources and sinks for isotope mass balance considerations. For the first time, we present a time-series of d15N values of atmospheric input at the same locations as d15N values of living Sphagnum and peat. The mean d15N values systematically increased in the order: input NH4+ (-10.0 per mil) < input NO3- (-7.9 per mil) < peat porewater (-5.6 per mil) < Sphagnum (-5.0 per mil) < shallow peat (-4.2 per mil) < deep peat (-2.2 per mil) < runoff (-1.4 per mil) < porewater N2O (1.4 per mil). Surprisingly, N of Sphagnum was isotopically heavier than N of the atmospheric input (P < 0.001). If partial incorporation of reactive N from the atmosphere into Sphagnum was isotopically selective, the residual N would have to be isotopically extremely light. Such N, however, was not identified anywhere in the ecosystem. Alternatively, Sphagnum may have contained an admixture of isotopically heavier N. Ambient air contains such N in the form of N2 (d15N-N2 = 0 per mil). Because high energy is required to break the triple bond, microbial N fixation is likely to proceed only under limited availability of pollutant N. Also for the first time, a d15N comparison is presented between anoxic deeper peat and porewater N2O. Isotopically light N is removed from anoxic substrate by denitrification, whose final product, N2, escapes into the atmosphere. Porewater N2O is an isotopically heavy residuum following partial N2O reduction to N2.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

DD - Geochemie

OECD FORD obor

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Projekt

<a href="/cs/project/GA16-18079S" target="_blank" >GA16-18079S: Izotopové doklady mikrobiální fixace dusíku v ombrotrofních mokřadech</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Ecosystems

ISSN

1432-9840

e-ISSN

—

Svazek periodika

19

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

16

Strana od-do

1037-1050

Kód UT WoS článku

000386710000007

EID výsledku v databázi Scopus

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