Variation in N-2 fixation in subarctic tundra in relation to landscape position and nitrogen pools and fluxes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60076658%3A12310%2F16%3A43890903" target="_blank" >RIV/60076658:12310/16:43890903 - isvavai.cz</a>

Výsledek na webu

<a href="http://www.bioone.org/doi/10.1657/AAAR0014-064" target="_blank" >http://www.bioone.org/doi/10.1657/AAAR0014-064</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1657/AAAR0014-064" target="_blank" >10.1657/AAAR0014-064</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Variation in N-2 fixation in subarctic tundra in relation to landscape position and nitrogen pools and fluxes

Popis výsledku v původním jazyce

Biological N-2 fixation in high-latitude ecosystems usually exhibits low rates but can significantly contribute to the local N budget. We studied N-2 fixation in three habitats of East European subarctic tundra differing in soil N stocks and fluxes: N-limited vegetated peat plateau (PP), frost formations of bare peat called "peat circles" (PC) with high availability of soil N, and vegetated upland tundra (UT) with low to intermediate N-availability. Nitrogen fixation was measured at field conditions twice during summer 2011 by acetylene reduction assay, and N-2 fixation rates were verified by 15N(2) fixation assay. Response to variation in nutrients, carbon, and temperature was studied in complementary laboratory experiments. Further, we aimed to link N-2 fixation rates to N deposition and major N transformation rates (gross and net mineralization, plant N uptake) including high N2O emissions recently found from PC. We hypothesized that N2O emissions in PC were fueled partly by biologically fixed N. Contrary to that hypothesis, N-2 fixation was found solely in PP (0.01-0.76 mg N m(-2) d(-1)), where N-2 was fixed by moss-associated cyanobacteria and heterotrophic soil bacteria. The low N and high P availability corresponded with the occurrence of N-2 fixation in these soils. Nitrogen fixation represented only a small portion of plant N uptake in PP. Conversely, bare PC (as well as vegetated UT) lacked N-2 fixation and thus N2O efflux is most likely fueled by release of mineral N to the soil through internal nutrient cycling.

Název v anglickém jazyce

Variation in N-2 fixation in subarctic tundra in relation to landscape position and nitrogen pools and fluxes

Popis výsledku anglicky

Biological N-2 fixation in high-latitude ecosystems usually exhibits low rates but can significantly contribute to the local N budget. We studied N-2 fixation in three habitats of East European subarctic tundra differing in soil N stocks and fluxes: N-limited vegetated peat plateau (PP), frost formations of bare peat called "peat circles" (PC) with high availability of soil N, and vegetated upland tundra (UT) with low to intermediate N-availability. Nitrogen fixation was measured at field conditions twice during summer 2011 by acetylene reduction assay, and N-2 fixation rates were verified by 15N(2) fixation assay. Response to variation in nutrients, carbon, and temperature was studied in complementary laboratory experiments. Further, we aimed to link N-2 fixation rates to N deposition and major N transformation rates (gross and net mineralization, plant N uptake) including high N2O emissions recently found from PC. We hypothesized that N2O emissions in PC were fueled partly by biologically fixed N. Contrary to that hypothesis, N-2 fixation was found solely in PP (0.01-0.76 mg N m(-2) d(-1)), where N-2 was fixed by moss-associated cyanobacteria and heterotrophic soil bacteria. The low N and high P availability corresponded with the occurrence of N-2 fixation in these soils. Nitrogen fixation represented only a small portion of plant N uptake in PP. Conversely, bare PC (as well as vegetated UT) lacked N-2 fixation and thus N2O efflux is most likely fueled by release of mineral N to the soil through internal nutrient cycling.

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/7E10073" target="_blank" >7E10073: Long-term Carbon Storage in Cryoturbeated Arctic Soils</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Arctic, Antarctic and Alpine Research

ISSN

1523-0430

e-ISSN

—

Svazek periodika

48

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

111-125

Kód UT WoS článku

000371322100008

EID výsledku v databázi Scopus

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