Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data
<p>The urgent need to mitigate climate change has evoked a broad interest in better understanding and estimating nitrous oxide (<span class="inline-formula">N<sub>2</sub>O</span>) emissions from different ecosystems. Part of the uncertainty in <span class=&...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2024-04-01
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| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/21/1867/2024/bg-21-1867-2024.pdf |
| _version_ | 1797202807173939200 |
|---|---|
| author | H. Rautakoski M. Korkiakoski J. Mäkelä M. Koskinen K. Minkkinen M. Aurela P. Ojanen P. Ojanen A. Lohila A. Lohila |
| author_facet | H. Rautakoski M. Korkiakoski J. Mäkelä M. Koskinen K. Minkkinen M. Aurela P. Ojanen P. Ojanen A. Lohila A. Lohila |
| author_sort | H. Rautakoski |
| collection | DOAJ |
| description | <p>The urgent need to mitigate climate change has evoked a broad interest in better understanding and estimating nitrous oxide (<span class="inline-formula">N<sub>2</sub>O</span>) emissions from different ecosystems. Part of the uncertainty in <span class="inline-formula">N<sub>2</sub>O</span> emission estimates still comes from an inadequate understanding of the temporal and small-scale spatial variability of <span class="inline-formula">N<sub>2</sub>O</span> fluxes. Using 4.5 years of <span class="inline-formula">N<sub>2</sub>O</span> flux data collected in a drained peatland forest with six automated chambers, we explored temporal and small-scale spatial variability of <span class="inline-formula">N<sub>2</sub>O</span> fluxes. A random forest with conditional inference trees was used to find immediate and delayed relationships between <span class="inline-formula">N<sub>2</sub>O</span> flux and environmental conditions across seasons and years.</p>
<p>The spatiotemporal variation of the <span class="inline-formula">N<sub>2</sub>O</span> flux was large, with daily mean <span class="inline-formula">N<sub>2</sub>O</span> flux varying between <span class="inline-formula">−</span>10 and <span class="inline-formula">+</span>1760 <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">µ</mi><mi mathvariant="normal">g</mi><mspace linebreak="nobreak" width="0.125em"/><msub><mi mathvariant="normal">N</mi><mn mathvariant="normal">2</mn></msub><mi mathvariant="normal">O</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">2</mn></mrow></msup><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">h</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="75pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="ff12e5abe417d719b0b51e378e662455"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-1867-2024-ie00001.svg" width="75pt" height="16pt" src="bg-21-1867-2024-ie00001.png"/></svg:svg></span></span> and annual <span class="inline-formula">N<sub>2</sub>O</span> budgets of different chambers between <span class="inline-formula">+</span>60 and <span class="inline-formula">+</span>2110 <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M15" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">mg</mi><mspace width="0.125em" linebreak="nobreak"/><msub><mi mathvariant="normal">N</mi><mn mathvariant="normal">2</mn></msub><mi mathvariant="normal">O</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">2</mn></mrow></msup><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">yr</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="82pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="1af2bfe9f0c99bbb75e0d465edd45405"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-1867-2024-ie00002.svg" width="82pt" height="16pt" src="bg-21-1867-2024-ie00002.png"/></svg:svg></span></span>. Spatial differences in fluxes persisted through years of different environmental conditions. Soil moisture, water table level, and air temperature were the most important variables explaining the temporal variation of <span class="inline-formula">N<sub>2</sub>O</span> fluxes. <span class="inline-formula">N<sub>2</sub>O</span> fluxes responded to precipitation events with peak fluxes measured on average 4 d after peaks in soil moisture and water table level. The length of the time lags varied in space and between seasons indicating possible interactions with temperature and other soil conditions.</p>
<p>The high temporal variation in <span class="inline-formula">N<sub>2</sub>O</span> flux was related to (a) temporal variation in environmental conditions, with the highest <span class="inline-formula">N<sub>2</sub>O</span> fluxes measured after summer precipitation events and winter soil freezing, and (b) to annually varying seasonal weather conditions, with the highest <span class="inline-formula">N<sub>2</sub>O</span> emissions measured during wet summers and winters with discontinuous snow cover. Climate change may thus increase winter <span class="inline-formula">N<sub>2</sub>O</span> emissions, which may be offset by lower summer <span class="inline-formula">N<sub>2</sub>O</span> emissions in dry years. The high sensitivity of <span class="inline-formula">N<sub>2</sub>O</span> fluxes to seasonal weather conditions suggests increasing variability in annual peatland forest <span class="inline-formula">N<sub>2</sub>O</span> budgets as the frequency of extreme weather events, such as droughts, is predicted to increase.</p> |
| first_indexed | 2024-04-24T08:09:18Z |
| format | Article |
| id | doaj.art-4f1b322f36ea43ff82038a1d4780c2ea |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-04-24T08:09:18Z |
| publishDate | 2024-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-4f1b322f36ea43ff82038a1d4780c2ea2024-04-17T07:14:17ZengCopernicus PublicationsBiogeosciences1726-41701726-41892024-04-01211867188610.5194/bg-21-1867-2024Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber dataH. Rautakoski0M. Korkiakoski1J. Mäkelä2M. Koskinen3K. Minkkinen4M. Aurela5P. Ojanen6P. Ojanen7A. Lohila8A. Lohila9Climate System Research, Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, FinlandClimate System Research, Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, FinlandAdvanced Computing Facility, CSC – IT Center for Science Ltd, P.O. Box 405, 02101 Espoo, FinlandDepartment of Agriculture, University of Helsinki, Viikinkaari 9, 00790 Helsinki, FinlandDepartment of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, FinlandClimate System Research, Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, FinlandDepartment of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, FinlandNatural Resources Institute Finland, Viikinkaari 4, 00790 Helsinki, FinlandClimate System Research, Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, FinlandInstitute for Atmospheric and Earth System Research, University of Helsinki, Gustaf Hällströmin katu 2, P.O. Box 64, 00014 Helsinki, Finland<p>The urgent need to mitigate climate change has evoked a broad interest in better understanding and estimating nitrous oxide (<span class="inline-formula">N<sub>2</sub>O</span>) emissions from different ecosystems. Part of the uncertainty in <span class="inline-formula">N<sub>2</sub>O</span> emission estimates still comes from an inadequate understanding of the temporal and small-scale spatial variability of <span class="inline-formula">N<sub>2</sub>O</span> fluxes. Using 4.5 years of <span class="inline-formula">N<sub>2</sub>O</span> flux data collected in a drained peatland forest with six automated chambers, we explored temporal and small-scale spatial variability of <span class="inline-formula">N<sub>2</sub>O</span> fluxes. A random forest with conditional inference trees was used to find immediate and delayed relationships between <span class="inline-formula">N<sub>2</sub>O</span> flux and environmental conditions across seasons and years.</p> <p>The spatiotemporal variation of the <span class="inline-formula">N<sub>2</sub>O</span> flux was large, with daily mean <span class="inline-formula">N<sub>2</sub>O</span> flux varying between <span class="inline-formula">−</span>10 and <span class="inline-formula">+</span>1760 <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">µ</mi><mi mathvariant="normal">g</mi><mspace linebreak="nobreak" width="0.125em"/><msub><mi mathvariant="normal">N</mi><mn mathvariant="normal">2</mn></msub><mi mathvariant="normal">O</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">2</mn></mrow></msup><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">h</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="75pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="ff12e5abe417d719b0b51e378e662455"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-1867-2024-ie00001.svg" width="75pt" height="16pt" src="bg-21-1867-2024-ie00001.png"/></svg:svg></span></span> and annual <span class="inline-formula">N<sub>2</sub>O</span> budgets of different chambers between <span class="inline-formula">+</span>60 and <span class="inline-formula">+</span>2110 <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M15" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">mg</mi><mspace width="0.125em" linebreak="nobreak"/><msub><mi mathvariant="normal">N</mi><mn mathvariant="normal">2</mn></msub><mi mathvariant="normal">O</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">2</mn></mrow></msup><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">yr</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="82pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="1af2bfe9f0c99bbb75e0d465edd45405"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-1867-2024-ie00002.svg" width="82pt" height="16pt" src="bg-21-1867-2024-ie00002.png"/></svg:svg></span></span>. Spatial differences in fluxes persisted through years of different environmental conditions. Soil moisture, water table level, and air temperature were the most important variables explaining the temporal variation of <span class="inline-formula">N<sub>2</sub>O</span> fluxes. <span class="inline-formula">N<sub>2</sub>O</span> fluxes responded to precipitation events with peak fluxes measured on average 4 d after peaks in soil moisture and water table level. The length of the time lags varied in space and between seasons indicating possible interactions with temperature and other soil conditions.</p> <p>The high temporal variation in <span class="inline-formula">N<sub>2</sub>O</span> flux was related to (a) temporal variation in environmental conditions, with the highest <span class="inline-formula">N<sub>2</sub>O</span> fluxes measured after summer precipitation events and winter soil freezing, and (b) to annually varying seasonal weather conditions, with the highest <span class="inline-formula">N<sub>2</sub>O</span> emissions measured during wet summers and winters with discontinuous snow cover. Climate change may thus increase winter <span class="inline-formula">N<sub>2</sub>O</span> emissions, which may be offset by lower summer <span class="inline-formula">N<sub>2</sub>O</span> emissions in dry years. The high sensitivity of <span class="inline-formula">N<sub>2</sub>O</span> fluxes to seasonal weather conditions suggests increasing variability in annual peatland forest <span class="inline-formula">N<sub>2</sub>O</span> budgets as the frequency of extreme weather events, such as droughts, is predicted to increase.</p>https://bg.copernicus.org/articles/21/1867/2024/bg-21-1867-2024.pdf |
| spellingShingle | H. Rautakoski M. Korkiakoski J. Mäkelä M. Koskinen K. Minkkinen M. Aurela P. Ojanen P. Ojanen A. Lohila A. Lohila Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data Biogeosciences |
| title | Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data |
| title_full | Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data |
| title_fullStr | Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data |
| title_full_unstemmed | Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data |
| title_short | Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data |
| title_sort | exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data |
| url | https://bg.copernicus.org/articles/21/1867/2024/bg-21-1867-2024.pdf |
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