Contrasting potential for biological N 2 fixation at three polluted central European Sphagnum peat bogs: combining the 15 N 2 -tracer and natural-abundance isotope approaches

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F23%3A10488932" target="_blank" >RIV/00216208:11320/23:10488932 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=G.4~sKHihl" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=G.4~sKHihl</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.5194/soil-9-623-2023" target="_blank" >10.5194/soil-9-623-2023</a>

Result language

angličtina

Original language name

Contrasting potential for biological N 2 fixation at three polluted central European Sphagnum peat bogs: combining the 15 N 2 -tracer and natural-abundance isotope approaches

Original language description

Availability of reactive nitrogen (N-r) is a key control on carbon (C) sequestration in wetlands. To complement the metabolic demands of Sphagnumin pristine rain-fed bogs, diazotrophs supply additional Nrvia biological nitrogen fixation (BNF). As breaking the triple bond of atmospheric N(2 )is energy-intensive, it is reasonable to assume that increasing inputs of pollutant N-r will lead to BNF downregulation. However, recent studies have also documented measurable BNF rates in Sphagnum-dominated bogs in polluted regions, indicating the adaptation of N2fixers to changing N deposition. Our aim was to quantify BNF in high-elevation peatlandslocated in industrialized central Europe. A(15)N(2)-tracer experiment was combined with a natural-abundance N-isotope study at three Sphagnum-dominated peat bogs in the northern Czech Republic in an attempt to assessthe roles of individual BNF drivers. High short-term BNF rates (8.2 +/- 4.6 g N m(2)d(-1)) were observed at Mal &amp; eacute;mechov &amp; eacute; jez &amp; iacute;rko, which receives similar to 17 kg Nrha(-1)yr(-1). The remaining two peat bogs, whose recent atmospheric Nrinputs differed from Mal &amp; eacute; mechov &amp; eacute; jez &amp; iacute;rko by only 1-2 kg ha(-1)yr(-1)(Uhl &amp; iacute;rsk &amp; aacute; and Brumi &amp; scaron;te), showed zeroBNF. The following parameters were investigated to elucidate the BNF difference: the NH+4-N/NO3--N ratio, temperature, wetness, Sphagnumspecies, organic-N availability, possible P limitation, possible molybdenum(Mo) limitation, SO(4)(2-)deposition, and pH. At Malmechov &amp; eacute; jez &amp; iacute;rko and Uhl &amp; iacute;rsk &amp; aacute;, the same moss species (S.girgensohnii) was used for the (15)N(2 )experiment; therefore, the host identity could not explain the difference in BNF at these sites. Temperature and moisture were also identical in all incubations and could not explainthe between-site differences in BNF. The N : P stoichiometry in peat and bog water indicated that Brumi &amp; scaron;emay have lacked BNF due to P limitation, whereas non-detectable BNF at Uhl &amp; iacute;rsk &amp; aacute; may have been related tothe 70-fold higher SO2-4concentration in bog water. Across the sites, the mean natural-abundance delta 15N valuesincreased in the following order: atmospheric deposition (-5.3 +/- 0.3 parts per thousand)&lt;Sphagnum(-4.3 +/- 0.1 parts per thousand)&lt;bog water (-3.9 +/- 0.4 parts per thousand)&lt;atmospheric N2(0.0 parts per thousand). Only at Brumi &amp; scaron;te was N in Sphagnum significantly isotopically heavier than in atmospheric deposition, possibly indicating a longer-term BNF effect. Collectively, our data highlight spatial heterogeneity in BNF rates under high N(r )inputs as well as the importance of environmental parameters other than atmospheric N-r pollution in regulating BNF

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10505 - Geology

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

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

Name of the periodical

SOIL

ISSN

2199-3971

e-ISSN

2199-398X

Volume of the periodical

9

Issue of the periodical within the volume

2

Country of publishing house

DE - GERMANY

Number of pages

18

Pages from-to

623-640

UT code for WoS article

001170599600001

EID of the result in the Scopus database

2-s2.0-85182993350