Gloria M. S. Reithmaier, Damien T. Maher, Ceylena Holloway, Rogger E. Correa, Isaac R. Santos
{"title":"小型湿地河口向海洋排放的碳负荷过大","authors":"Gloria M. S. Reithmaier, Damien T. Maher, Ceylena Holloway, Rogger E. Correa, Isaac R. Santos","doi":"10.1002/lno.12660","DOIUrl":null,"url":null,"abstract":"<p>Previous estimates of dissolved carbon export from estuaries focused on larger systems in the Northern Hemisphere, with little data for smaller tropical estuaries often fringed by intertidal wetlands. We investigated lateral export (outwelling) and transformation rates of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and total alkalinity (TA) as well as CO<sub>2</sub> emissions from 18 diverse Australian estuaries. Most estuaries acted as net sources for DOC (72%), DIC (83%), and TA (50%). On average, estuaries exported 120 ± 55 and 344 ± 150 mmol m<sup>−2</sup> catchment yr<sup>−1</sup> DOC and DIC, respectively. Estuarine CO<sub>2</sub> emissions (33 ± 20 mmol m<sup>−2</sup> estuary d<sup>−1</sup>) equalled 13% ± 16% of the dissolved lateral carbon export. Carbon export positively correlated with runoff, rain, and intertidal wetland cover, and negatively correlated with estuary and catchment area. Mangroves and saltmarshes cover < 1% of all catchments but can contribute 46% ± 11% of the DOC and 67% ± 13% of the DIC exported to the ocean. Upscaling our observations, Australian estuaries export 2.8 ± 2.2 TgC yr<sup>−1</sup> DOC, 8.1 ± 6.2 TgC yr<sup>−1</sup> DIC, and 0.7 ± 0.6 Tmol yr<sup>−1</sup> TA. Small catchments (< 10 ha) making up 70% of all estuaries and accounting for 18% of the total freshwater flow provided 27% to the total dissolved carbon export. Overall, small tropical estuaries fringed by highly productive intertidal wetlands are hotspots of carbon exports and should be considered in marine carbon budgets.</p>","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":null,"pages":null},"PeriodicalIF":3.8000,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.12660","citationCount":"0","resultStr":"{\"title\":\"Small wetland-fringed estuaries deliver disproportionately large carbon loads to the ocean\",\"authors\":\"Gloria M. S. Reithmaier, Damien T. Maher, Ceylena Holloway, Rogger E. Correa, Isaac R. Santos\",\"doi\":\"10.1002/lno.12660\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Previous estimates of dissolved carbon export from estuaries focused on larger systems in the Northern Hemisphere, with little data for smaller tropical estuaries often fringed by intertidal wetlands. We investigated lateral export (outwelling) and transformation rates of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and total alkalinity (TA) as well as CO<sub>2</sub> emissions from 18 diverse Australian estuaries. Most estuaries acted as net sources for DOC (72%), DIC (83%), and TA (50%). On average, estuaries exported 120 ± 55 and 344 ± 150 mmol m<sup>−2</sup> catchment yr<sup>−1</sup> DOC and DIC, respectively. Estuarine CO<sub>2</sub> emissions (33 ± 20 mmol m<sup>−2</sup> estuary d<sup>−1</sup>) equalled 13% ± 16% of the dissolved lateral carbon export. Carbon export positively correlated with runoff, rain, and intertidal wetland cover, and negatively correlated with estuary and catchment area. Mangroves and saltmarshes cover < 1% of all catchments but can contribute 46% ± 11% of the DOC and 67% ± 13% of the DIC exported to the ocean. Upscaling our observations, Australian estuaries export 2.8 ± 2.2 TgC yr<sup>−1</sup> DOC, 8.1 ± 6.2 TgC yr<sup>−1</sup> DIC, and 0.7 ± 0.6 Tmol yr<sup>−1</sup> TA. Small catchments (< 10 ha) making up 70% of all estuaries and accounting for 18% of the total freshwater flow provided 27% to the total dissolved carbon export. Overall, small tropical estuaries fringed by highly productive intertidal wetlands are hotspots of carbon exports and should be considered in marine carbon budgets.</p>\",\"PeriodicalId\":18143,\"journal\":{\"name\":\"Limnology and Oceanography\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.8000,\"publicationDate\":\"2024-08-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.12660\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Limnology and Oceanography\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/lno.12660\",\"RegionNum\":1,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"LIMNOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Limnology and Oceanography","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/lno.12660","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"LIMNOLOGY","Score":null,"Total":0}
Small wetland-fringed estuaries deliver disproportionately large carbon loads to the ocean
Previous estimates of dissolved carbon export from estuaries focused on larger systems in the Northern Hemisphere, with little data for smaller tropical estuaries often fringed by intertidal wetlands. We investigated lateral export (outwelling) and transformation rates of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and total alkalinity (TA) as well as CO2 emissions from 18 diverse Australian estuaries. Most estuaries acted as net sources for DOC (72%), DIC (83%), and TA (50%). On average, estuaries exported 120 ± 55 and 344 ± 150 mmol m−2 catchment yr−1 DOC and DIC, respectively. Estuarine CO2 emissions (33 ± 20 mmol m−2 estuary d−1) equalled 13% ± 16% of the dissolved lateral carbon export. Carbon export positively correlated with runoff, rain, and intertidal wetland cover, and negatively correlated with estuary and catchment area. Mangroves and saltmarshes cover < 1% of all catchments but can contribute 46% ± 11% of the DOC and 67% ± 13% of the DIC exported to the ocean. Upscaling our observations, Australian estuaries export 2.8 ± 2.2 TgC yr−1 DOC, 8.1 ± 6.2 TgC yr−1 DIC, and 0.7 ± 0.6 Tmol yr−1 TA. Small catchments (< 10 ha) making up 70% of all estuaries and accounting for 18% of the total freshwater flow provided 27% to the total dissolved carbon export. Overall, small tropical estuaries fringed by highly productive intertidal wetlands are hotspots of carbon exports and should be considered in marine carbon budgets.
期刊介绍:
Limnology and Oceanography (L&O; print ISSN 0024-3590, online ISSN 1939-5590) publishes original articles, including scholarly reviews, about all aspects of limnology and oceanography. The journal''s unifying theme is the understanding of aquatic systems. Submissions are judged on the originality of their data, interpretations, and ideas, and on the degree to which they can be generalized beyond the particular aquatic system examined. Laboratory and modeling studies must demonstrate relevance to field environments; typically this means that they are bolstered by substantial "real-world" data. Few purely theoretical or purely empirical papers are accepted for review.