The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific
<p>The availability of iron (Fe) and phosphorus (P) has been shown to be a key factor regulating rates of nitrogen fixation in the western subtropical Pacific. However, the relative importance of Fe and P at finer spatial scales between the northern South China Sea (NSCS) and the western bound...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-11-01
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| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/19/5237/2022/bg-19-5237-2022.pdf |
| _version_ | 1811308034414084096 |
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| author | Z. Wen Z. Wen T. J. Browning R. Dai W. Wu W. Li W. Li X. Hu W. Lin L. Wang X. Liu Z. Cao H. Hong D. Shi |
| author_facet | Z. Wen Z. Wen T. J. Browning R. Dai W. Wu W. Li W. Li X. Hu W. Lin L. Wang X. Liu Z. Cao H. Hong D. Shi |
| author_sort | Z. Wen |
| collection | DOAJ |
| description | <p>The availability of iron (Fe) and phosphorus (P) has been shown
to be a key factor regulating rates of nitrogen fixation in the western
subtropical Pacific. However, the relative importance of Fe and P at finer spatial
scales between the northern South China Sea (NSCS) and the western boundary
of the North Pacific is poorly constrained. Furthermore, nutrient limitation
of specific diazotroph types has not yet been assessed. Here we investigated
these unknowns by (i) carrying out measurements of finer-scale spatial
variabilities in N<span class="inline-formula"><sub>2</sub></span> fixation rates and diazotroph <i>nifH</i> gene abundances
throughout these regions and (ii) conducting eight additional Fe and
phosphate addition bioassay experiments where both changes in N<span class="inline-formula"><sub>2</sub></span>
fixation rates and the <i>nifH</i> gene abundances of specific diazotrophs were
measured. Overall, nitrogen fixation rates and <i>nifH</i> gene abundances were lower
in the NSCS than around the Luzon Strait and the western North Pacific. The
nutrient addition bioassay experiments demonstrated that N<span class="inline-formula"><sub>2</sub></span> fixation
rates in the central NSCS were co-limited by Fe and P, whereas at the
western boundary of the North Pacific they were P-limited. Changes in the
abundances of <i>nifH</i> in response to nutrient addition varied in how well they
correlated with changes in N<span class="inline-formula"><sub>2</sub></span> fixation rates, and in six out of eight
experiments the largest responses in <i>nifH</i> gene abundances were dominated by
either <i>Trichodesmium</i> or UCYN-B (unicellular diazotrophic cyanobacteria group B). In general, nutrient addition had a relatively restricted
impact on the composition of the six phylotypes that we surveyed apart from
on UCYN-B. This unicellular cyanobacterium group showed increased
contribution to the total <i>nifH</i> gene abundance following P addition at sites
where N<span class="inline-formula"><sub>2</sub></span> fixation rates were P-limited. Our study provides
comprehensive evidence of nutrient controls on N<span class="inline-formula"><sub>2</sub></span> fixation biogeography
in the margin of the western North Pacific. Future research that more
accurately constrains nutrient supply rates to this region would be
beneficial for resolving what controls diazotroph community structure.</p> |
| first_indexed | 2024-04-13T09:15:57Z |
| format | Article |
| id | doaj.art-c302a85cddf24cc79d7cac2b62fcc82b |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-04-13T09:15:57Z |
| publishDate | 2022-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-c302a85cddf24cc79d7cac2b62fcc82b2022-12-22T02:52:45ZengCopernicus PublicationsBiogeosciences1726-41701726-41892022-11-01195237525010.5194/bg-19-5237-2022The response of diazotrophs to nutrient amendment in the South China Sea and western North PacificZ. Wen0Z. Wen1T. J. Browning2R. Dai3W. Wu4W. Li5W. Li6X. Hu7W. Lin8L. Wang9X. Liu10Z. Cao11H. Hong12D. Shi13State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR ChinaMarine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, GermanyMarine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, GermanyState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR ChinaState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR ChinaState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR Chinapresent address: Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, Zhejiang, PR ChinaState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR ChinaState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR ChinaState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR ChinaState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR ChinaState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR ChinaState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR ChinaState Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, PR China<p>The availability of iron (Fe) and phosphorus (P) has been shown to be a key factor regulating rates of nitrogen fixation in the western subtropical Pacific. However, the relative importance of Fe and P at finer spatial scales between the northern South China Sea (NSCS) and the western boundary of the North Pacific is poorly constrained. Furthermore, nutrient limitation of specific diazotroph types has not yet been assessed. Here we investigated these unknowns by (i) carrying out measurements of finer-scale spatial variabilities in N<span class="inline-formula"><sub>2</sub></span> fixation rates and diazotroph <i>nifH</i> gene abundances throughout these regions and (ii) conducting eight additional Fe and phosphate addition bioassay experiments where both changes in N<span class="inline-formula"><sub>2</sub></span> fixation rates and the <i>nifH</i> gene abundances of specific diazotrophs were measured. Overall, nitrogen fixation rates and <i>nifH</i> gene abundances were lower in the NSCS than around the Luzon Strait and the western North Pacific. The nutrient addition bioassay experiments demonstrated that N<span class="inline-formula"><sub>2</sub></span> fixation rates in the central NSCS were co-limited by Fe and P, whereas at the western boundary of the North Pacific they were P-limited. Changes in the abundances of <i>nifH</i> in response to nutrient addition varied in how well they correlated with changes in N<span class="inline-formula"><sub>2</sub></span> fixation rates, and in six out of eight experiments the largest responses in <i>nifH</i> gene abundances were dominated by either <i>Trichodesmium</i> or UCYN-B (unicellular diazotrophic cyanobacteria group B). In general, nutrient addition had a relatively restricted impact on the composition of the six phylotypes that we surveyed apart from on UCYN-B. This unicellular cyanobacterium group showed increased contribution to the total <i>nifH</i> gene abundance following P addition at sites where N<span class="inline-formula"><sub>2</sub></span> fixation rates were P-limited. Our study provides comprehensive evidence of nutrient controls on N<span class="inline-formula"><sub>2</sub></span> fixation biogeography in the margin of the western North Pacific. Future research that more accurately constrains nutrient supply rates to this region would be beneficial for resolving what controls diazotroph community structure.</p>https://bg.copernicus.org/articles/19/5237/2022/bg-19-5237-2022.pdf |
| spellingShingle | Z. Wen Z. Wen T. J. Browning R. Dai W. Wu W. Li W. Li X. Hu W. Lin L. Wang X. Liu Z. Cao H. Hong D. Shi The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific Biogeosciences |
| title | The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific |
| title_full | The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific |
| title_fullStr | The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific |
| title_full_unstemmed | The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific |
| title_short | The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific |
| title_sort | response of diazotrophs to nutrient amendment in the south china sea and western north pacific |
| url | https://bg.copernicus.org/articles/19/5237/2022/bg-19-5237-2022.pdf |
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