Contrasting potential for biological N<sub>2</sub> fixation at three polluted central European <i>Sphagnum</i> peat bogs: combining the <sup>15</sup>N<sub>2</sub>-tracer and natural-abundance isotope approaches
<p>Availability of reactive nitrogen (N<span class="inline-formula"><sub>r</sub></span>) is a key control on carbon (C) sequestration in wetlands. To complement the metabolic demands of <i>Sphagnum</i> in pristine rain-fed bogs, diazotrophs supply...
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-12-01
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| Series: | SOIL |
| Online Access: | https://soil.copernicus.org/articles/9/623/2023/soil-9-623-2023.pdf |
| _version_ | 1797382634117005312 |
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| author | M. Stepanova M. Novak B. Cejkova I. Jackova F. Buzek F. Veselovsky J. Curik E. Prechova A. Komarek L. Bohdalkova |
| author_facet | M. Stepanova M. Novak B. Cejkova I. Jackova F. Buzek F. Veselovsky J. Curik E. Prechova A. Komarek L. Bohdalkova |
| author_sort | M. Stepanova |
| collection | DOAJ |
| description | <p>Availability of reactive nitrogen (N<span class="inline-formula"><sub>r</sub></span>) is a key control on carbon (C) sequestration in wetlands. To complement the metabolic demands of <i>Sphagnum</i> in pristine rain-fed bogs, diazotrophs supply additional N<span class="inline-formula"><sub>r</sub></span> via biological nitrogen fixation (BNF). As breaking the triple bond of atmospheric N<span class="inline-formula"><sub>2</sub></span> is energy-intensive, it is reasonable to assume that increasing inputs of pollutant N<span class="inline-formula"><sub>r</sub></span> will lead to BNF downregulation. However, recent studies have also documented measurable BNF rates in <i>Sphagnum</i>-dominated bogs in polluted regions, indicating the adaptation of N<span class="inline-formula"><sub>2</sub></span> fixers to changing N deposition. Our aim was to quantify BNF in high-elevation peatlands located in industrialized central Europe. A <span class="inline-formula"><sup>15</sup></span>N<span class="inline-formula"><sub>2</sub></span>-tracer experiment was combined with a natural-abundance N-isotope study at three <i>Sphagnum</i>-dominated peat bogs in the northern Czech Republic in an attempt to assess the roles of individual BNF drivers. High short-term BNF rates (8.2 <span class="inline-formula">±</span> 4.6 g N m<span class="inline-formula"><sup>2</sup></span> d<span class="inline-formula"><sup>−1</sup></span>) were observed at Malé mechové jezírko, which receives <span class="inline-formula">∼</span> 17 kg N<span class="inline-formula"><sub>r</sub></span> ha<span class="inline-formula"><sup>−1</sup></span> yr<span class="inline-formula"><sup>−1</sup></span>. The remaining two peat bogs, whose recent atmospheric N<span class="inline-formula"><sub>r</sub></span> inputs differed from Malé mechové jezírko by only 1–2 kg ha<span class="inline-formula"><sup>−1</sup></span> yr<span class="inline-formula"><sup>−1</sup></span> (Uhlír̆ská and Brumiště), showed zero BNF. The following parameters were investigated to elucidate the BNF difference: the NH<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M22" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="51ca01690260423140b5b0de9583232a"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00001.svg" width="8pt" height="15pt" src="soil-9-623-2023-ie00001.png"/></svg:svg></span></span>-N <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M23" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="265e2a7d42d09da6c1e252e5649f9787"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00002.svg" width="8pt" height="14pt" src="soil-9-623-2023-ie00002.png"/></svg:svg></span></span> NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M24" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">3</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="d615913ec88b34ee0c05b0f0374db64d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00003.svg" width="9pt" height="16pt" src="soil-9-623-2023-ie00003.png"/></svg:svg></span></span>-N ratio, temperature, wetness, <i>Sphagnum</i> species, organic-N availability, possible P limitation, possible molybdenum (Mo) limitation, SO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M25" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="820c2a883eb6831c3f3dfbf9fe5018ac"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00004.svg" width="13pt" height="17pt" src="soil-9-623-2023-ie00004.png"/></svg:svg></span></span> deposition, and pH. At Malé mechové jezírko and Uhlír̆ská, the same moss species (<i>S. girgensohnii</i>) was used for the <span class="inline-formula"><sup>15</sup></span>N<span class="inline-formula"><sub>2</sub></span> 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 explain the between-site differences in BNF. The N : P stoichiometry in peat and bog water indicated that Brumiště may have lacked BNF due to P limitation, whereas non-detectable BNF at Uhlír̆ská may have been related to the 70-fold higher SO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M28" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="af7843922aebc745671236cec92f9569"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00005.svg" width="13pt" height="17pt" src="soil-9-623-2023-ie00005.png"/></svg:svg></span></span> concentration in bog water. Across the sites, the mean natural-abundance <span class="inline-formula"><i>δ</i><sup>15</sup></span>N values increased in the following order: atmospheric deposition (<span class="inline-formula">−</span>5.3 <span class="inline-formula">±</span> 0.3 ‰) <span class="inline-formula"><i><</i></span> <i>Sphagnum</i> (<span class="inline-formula">−</span>4.3 <span class="inline-formula">±</span> 0.1 ‰) <span class="inline-formula"><i><</i></span> bog water (<span class="inline-formula">−</span>3.9 <span class="inline-formula">±</span> 0.4 ‰) <span class="inline-formula"><i><</i></span> atmospheric N<span class="inline-formula"><sub>2</sub></span> (0.0 ‰). Only at Brumiště was N in <i>Sphagnum</i> 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<span class="inline-formula"><sub>r</sub></span> inputs as well as the importance of environmental parameters other than atmospheric N<span class="inline-formula"><sub>r</sub></span> pollution in regulating BNF.</p> |
| first_indexed | 2024-03-08T21:09:15Z |
| format | Article |
| id | doaj.art-3612c07cd55c4207891129a0c561d62f |
| institution | Directory Open Access Journal |
| issn | 2199-3971 2199-398X |
| language | English |
| last_indexed | 2024-03-08T21:09:15Z |
| publishDate | 2023-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | SOIL |
| spelling | doaj.art-3612c07cd55c4207891129a0c561d62f2023-12-22T10:23:09ZengCopernicus PublicationsSOIL2199-39712199-398X2023-12-01962364010.5194/soil-9-623-2023Contrasting potential for biological N<sub>2</sub> fixation at three polluted central European <i>Sphagnum</i> peat bogs: combining the <sup>15</sup>N<sub>2</sub>-tracer and natural-abundance isotope approachesM. Stepanova0M. Novak1B. Cejkova2I. Jackova3F. Buzek4F. Veselovsky5J. Curik6E. Prechova7A. Komarek8L. Bohdalkova9Department of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech RepublicDepartment of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech RepublicDepartment of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech RepublicDepartment of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech RepublicDepartment of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech RepublicDepartment of Rock Geochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech RepublicDepartment of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech RepublicDepartment of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech RepublicDepartment of Probability and Mathematic Statistics, Faculty of Mathematics and Physics, Charles University, Sokolovska 83, 186 75 Prague 8, Czech RepublicDepartment of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic<p>Availability of reactive nitrogen (N<span class="inline-formula"><sub>r</sub></span>) is a key control on carbon (C) sequestration in wetlands. To complement the metabolic demands of <i>Sphagnum</i> in pristine rain-fed bogs, diazotrophs supply additional N<span class="inline-formula"><sub>r</sub></span> via biological nitrogen fixation (BNF). As breaking the triple bond of atmospheric N<span class="inline-formula"><sub>2</sub></span> is energy-intensive, it is reasonable to assume that increasing inputs of pollutant N<span class="inline-formula"><sub>r</sub></span> will lead to BNF downregulation. However, recent studies have also documented measurable BNF rates in <i>Sphagnum</i>-dominated bogs in polluted regions, indicating the adaptation of N<span class="inline-formula"><sub>2</sub></span> fixers to changing N deposition. Our aim was to quantify BNF in high-elevation peatlands located in industrialized central Europe. A <span class="inline-formula"><sup>15</sup></span>N<span class="inline-formula"><sub>2</sub></span>-tracer experiment was combined with a natural-abundance N-isotope study at three <i>Sphagnum</i>-dominated peat bogs in the northern Czech Republic in an attempt to assess the roles of individual BNF drivers. High short-term BNF rates (8.2 <span class="inline-formula">±</span> 4.6 g N m<span class="inline-formula"><sup>2</sup></span> d<span class="inline-formula"><sup>−1</sup></span>) were observed at Malé mechové jezírko, which receives <span class="inline-formula">∼</span> 17 kg N<span class="inline-formula"><sub>r</sub></span> ha<span class="inline-formula"><sup>−1</sup></span> yr<span class="inline-formula"><sup>−1</sup></span>. The remaining two peat bogs, whose recent atmospheric N<span class="inline-formula"><sub>r</sub></span> inputs differed from Malé mechové jezírko by only 1–2 kg ha<span class="inline-formula"><sup>−1</sup></span> yr<span class="inline-formula"><sup>−1</sup></span> (Uhlír̆ská and Brumiště), showed zero BNF. The following parameters were investigated to elucidate the BNF difference: the NH<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M22" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="51ca01690260423140b5b0de9583232a"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00001.svg" width="8pt" height="15pt" src="soil-9-623-2023-ie00001.png"/></svg:svg></span></span>-N <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M23" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="265e2a7d42d09da6c1e252e5649f9787"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00002.svg" width="8pt" height="14pt" src="soil-9-623-2023-ie00002.png"/></svg:svg></span></span> NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M24" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">3</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="d615913ec88b34ee0c05b0f0374db64d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00003.svg" width="9pt" height="16pt" src="soil-9-623-2023-ie00003.png"/></svg:svg></span></span>-N ratio, temperature, wetness, <i>Sphagnum</i> species, organic-N availability, possible P limitation, possible molybdenum (Mo) limitation, SO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M25" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="820c2a883eb6831c3f3dfbf9fe5018ac"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00004.svg" width="13pt" height="17pt" src="soil-9-623-2023-ie00004.png"/></svg:svg></span></span> deposition, and pH. At Malé mechové jezírko and Uhlír̆ská, the same moss species (<i>S. girgensohnii</i>) was used for the <span class="inline-formula"><sup>15</sup></span>N<span class="inline-formula"><sub>2</sub></span> 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 explain the between-site differences in BNF. The N : P stoichiometry in peat and bog water indicated that Brumiště may have lacked BNF due to P limitation, whereas non-detectable BNF at Uhlír̆ská may have been related to the 70-fold higher SO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M28" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="af7843922aebc745671236cec92f9569"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="soil-9-623-2023-ie00005.svg" width="13pt" height="17pt" src="soil-9-623-2023-ie00005.png"/></svg:svg></span></span> concentration in bog water. Across the sites, the mean natural-abundance <span class="inline-formula"><i>δ</i><sup>15</sup></span>N values increased in the following order: atmospheric deposition (<span class="inline-formula">−</span>5.3 <span class="inline-formula">±</span> 0.3 ‰) <span class="inline-formula"><i><</i></span> <i>Sphagnum</i> (<span class="inline-formula">−</span>4.3 <span class="inline-formula">±</span> 0.1 ‰) <span class="inline-formula"><i><</i></span> bog water (<span class="inline-formula">−</span>3.9 <span class="inline-formula">±</span> 0.4 ‰) <span class="inline-formula"><i><</i></span> atmospheric N<span class="inline-formula"><sub>2</sub></span> (0.0 ‰). Only at Brumiště was N in <i>Sphagnum</i> 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<span class="inline-formula"><sub>r</sub></span> inputs as well as the importance of environmental parameters other than atmospheric N<span class="inline-formula"><sub>r</sub></span> pollution in regulating BNF.</p>https://soil.copernicus.org/articles/9/623/2023/soil-9-623-2023.pdf |
| spellingShingle | M. Stepanova M. Novak B. Cejkova I. Jackova F. Buzek F. Veselovsky J. Curik E. Prechova A. Komarek L. Bohdalkova Contrasting potential for biological N<sub>2</sub> fixation at three polluted central European <i>Sphagnum</i> peat bogs: combining the <sup>15</sup>N<sub>2</sub>-tracer and natural-abundance isotope approaches SOIL |
| title | Contrasting potential for biological N<sub>2</sub> fixation at three polluted central European <i>Sphagnum</i> peat bogs: combining the <sup>15</sup>N<sub>2</sub>-tracer and natural-abundance isotope approaches |
| title_full | Contrasting potential for biological N<sub>2</sub> fixation at three polluted central European <i>Sphagnum</i> peat bogs: combining the <sup>15</sup>N<sub>2</sub>-tracer and natural-abundance isotope approaches |
| title_fullStr | Contrasting potential for biological N<sub>2</sub> fixation at three polluted central European <i>Sphagnum</i> peat bogs: combining the <sup>15</sup>N<sub>2</sub>-tracer and natural-abundance isotope approaches |
| title_full_unstemmed | Contrasting potential for biological N<sub>2</sub> fixation at three polluted central European <i>Sphagnum</i> peat bogs: combining the <sup>15</sup>N<sub>2</sub>-tracer and natural-abundance isotope approaches |
| title_short | Contrasting potential for biological N<sub>2</sub> fixation at three polluted central European <i>Sphagnum</i> peat bogs: combining the <sup>15</sup>N<sub>2</sub>-tracer and natural-abundance isotope approaches |
| title_sort | contrasting potential for biological n sub 2 sub fixation at three polluted central european i sphagnum i peat bogs combining the sup 15 sup n sub 2 sub tracer and natural abundance isotope approaches |
| url | https://soil.copernicus.org/articles/9/623/2023/soil-9-623-2023.pdf |
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