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| Main Authors: | , , , , , , , |
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| Format: | Artículo científico |
| Language: | en |
| Published: |
Water research
2025
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| Subjects: | |
| Online Access: | https://pubmed.ncbi.nlm.nih.gov/39813892/ |
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| _version_ | 1868266255325069313 |
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| author | Su, Rui Zhao, Dayong Zhang, Xiaomin Zhang, Hongjie Cheng, Junxiang Xu, Ligang Wu, Qinglong L Zeng, Jin |
| author_facet | Su, Rui Zhao, Dayong Zhang, Xiaomin Zhang, Hongjie Cheng, Junxiang Xu, Ligang Wu, Qinglong L Zeng, Jin Su, Rui Zhao, Dayong Zhang, Xiaomin Zhang, Hongjie Cheng, Junxiang Xu, Ligang Wu, Qinglong L Zeng, Jin |
| collection | PubMed - marine biology |
| contents | Dissimilatory nitrate reduction pathways drive high nitrous oxide emissions and nitrogen retention under the flash drought in the largest freshwater lake in China. Su, Rui Zhao, Dayong Zhang, Xiaomin Zhang, Hongjie Cheng, Junxiang Xu, Ligang Wu, Qinglong L Zeng, Jin Nitrous Oxide Droughts China Lakes Nitrogen Nitrates Denitrification Climate Change Wetlands Flash drought (FD) events induced by climate change may disrupt the normal hydrological regimes of floodplain lakes and affect the plant-microbe mediated dissimilatory nitrate reduction (DNR), i.e., denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA), thus having important consequences for nitrous oxide (NO) emissions and nitrogen (N) retention. However, the responses of the DNR pathways in the floodplain lake to the record-breaking FD in 2022 in Yangtze River of China, as well as the underlying microbial mechanisms and feedbacks to climate change remain poorly understood. Here, we collected exposed sediments and Carex cinerascens-associated soils in the littoral wetlands of Poyang Lake during 2022 FD and the dry seasons prior to and after this event. The potential DNR rates and the synergistic metabolism of microbial guilds involved in DNR were investigated using N isotope pairing technique, high-throughput and metagenomic sequencing. We found that the in situ NO fluxes in the littoral wetlands were highest during the flash drought, especially in the exposed sediments. The potential DNRA rates were highest under flash drought conditions, and DNRA dominated the DNR for both exposed sediments (80.4 %) and Carex cinerascens-associated soils (57.5 %). Nutrients (i.e., N and P) and DNRA bacterial communities played a key role in producing the extremely high NO fluxes from exposed sediments, which could be explained by the synergistic metabolism of DNRA bacteria and denitrifiers through the exchange of the key intermediates in DNR. Therefore, the climate change-induced flash drought promoted greater nitrous oxide emissions and N retention in the littoral wetlands of Poyang Lake, producing a greater flux of greenhouse gas emissions and elevating the risk of lake eutrophication. Hence, flash droughts reinforce a positive feedback between climate change and nitrous oxide emission from these aquatic ecosystems. |
| format | Artículo científico |
| id | pubmed_39813892 |
| institution | PubMed |
| language | en |
| publishDate | 2025 |
| publisher | Water research |
| record_format | pubmed |
| spellingShingle | Dissimilatory nitrate reduction pathways drive high nitrous oxide emissions and nitrogen retention under the flash drought in the largest freshwater lake in China. Su, Rui Zhao, Dayong Zhang, Xiaomin Zhang, Hongjie Cheng, Junxiang Xu, Ligang Wu, Qinglong L Zeng, Jin Nitrous Oxide Droughts China Lakes Nitrogen Nitrates Denitrification Climate Change Wetlands Dissimilatory nitrate reduction pathways drive high nitrous oxide emissions and nitrogen retention under the flash drought in the largest freshwater lake in China. Su, Rui Zhao, Dayong Zhang, Xiaomin Zhang, Hongjie Cheng, Junxiang Xu, Ligang Wu, Qinglong L Zeng, Jin Nitrous Oxide Droughts China Lakes Nitrogen Nitrates Denitrification Climate Change Wetlands Flash drought (FD) events induced by climate change may disrupt the normal hydrological regimes of floodplain lakes and affect the plant-microbe mediated dissimilatory nitrate reduction (DNR), i.e., denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA), thus having important consequences for nitrous oxide (NO) emissions and nitrogen (N) retention. However, the responses of the DNR pathways in the floodplain lake to the record-breaking FD in 2022 in Yangtze River of China, as well as the underlying microbial mechanisms and feedbacks to climate change remain poorly understood. Here, we collected exposed sediments and Carex cinerascens-associated soils in the littoral wetlands of Poyang Lake during 2022 FD and the dry seasons prior to and after this event. The potential DNR rates and the synergistic metabolism of microbial guilds involved in DNR were investigated using N isotope pairing technique, high-throughput and metagenomic sequencing. We found that the in situ NO fluxes in the littoral wetlands were highest during the flash drought, especially in the exposed sediments. The potential DNRA rates were highest under flash drought conditions, and DNRA dominated the DNR for both exposed sediments (80.4 %) and Carex cinerascens-associated soils (57.5 %). Nutrients (i.e., N and P) and DNRA bacterial communities played a key role in producing the extremely high NO fluxes from exposed sediments, which could be explained by the synergistic metabolism of DNRA bacteria and denitrifiers through the exchange of the key intermediates in DNR. Therefore, the climate change-induced flash drought promoted greater nitrous oxide emissions and N retention in the littoral wetlands of Poyang Lake, producing a greater flux of greenhouse gas emissions and elevating the risk of lake eutrophication. Hence, flash droughts reinforce a positive feedback between climate change and nitrous oxide emission from these aquatic ecosystems. |
| title | Dissimilatory nitrate reduction pathways drive high nitrous oxide emissions and nitrogen retention under the flash drought in the largest freshwater lake in China. |
| topic | Nitrous Oxide Droughts China Lakes Nitrogen Nitrates Denitrification Climate Change Wetlands |
| url | https://pubmed.ncbi.nlm.nih.gov/39813892/ |