Groundwater Carbon Exports Exceed Sediment Carbon Burial in a Salt Marsh

Correa, Rogger E.1,2,3; Xiao, Kai4; Conrad, Stephen R.1; Wadnerkar, Praktan D.1; Wilson, Alicia M.5; Sanders, Christian J.1; Santos, Isaac R.1,6

2021-12-01

10.1007/s12237-021-01021-1

Estuaries and Coasts   影响因子和分区

1559-2723

1559-2731

Salt marshes can sequester large amounts of carbon in sediments, but the relation between carbon storage and exportation remains poorly understood. Groundwater exchange can flush sediment carbon to surface waters and potentially reduce storage. In this study, we estimated groundwater fluxes and associated carbon fluxes using a radon (Rn-222) mass balance and sediment carbon burial rates using lead (Pb-210) in a pristine salt marsh (North Inlet, SC, USA). We used delta C-13 to trace carbon origins. We found that groundwater releases large amounts of carbon to the open ocean. These groundwater fluxes have the potential to export 7.2 +/- 5.5 g m(-2) of dissolved inorganic carbon (DIC), 0.2 +/- 0.2 g m(-2) of dissolved organic carbon (DOC) and 0.7 +/- 0.5 g m(-2) of carbon dioxide (CO2) per day. The fluxes exceed the average surface water CO2 emissions (0.6 +/- 0.2 g m(-2) day(-1)) and the average sediment carbon burial rates (0.17 +/- 0.09 g m(-2) day(-1)). The delta C-13 results suggest that groundwater carbon originated from salt marsh soils, while the sediment carbon source is derived from salt marsh vegetation. We propose that the impact of salt marshes in carbon cycling depends not only on their capacity to bury carbon in sediments, but also on their high potential to export carbon to the ocean via groundwater pathways.

Submarine groundwater discharge Blue carbon Coastal carbon Radioactive tracers Coastal wetland

SCI

英语

其他

Australian Research Council[FT170100327] ; Swedish Research Council[2020-00457] ; National Natural Science Foundation of China[41907162]

Environmental Sciences & Ecology ; Marine & Freshwater Biology

Environmental Sciences ; Marine & Freshwater Biology

WOS:000725455700001

SPRINGER

Web of Science

1.Southern Cross Univ, Natl Marine Sci Ctr, POB 4321, Coffs Harbour, NSW 2450, Australia
2.Merceditas Corp, Medellin 050021, Colombia
3.Forestry Corp New South Wales, Coffs Harbour, NSW 2450, Australia
4.Southern Univ Sci & Technol, Sch Environm Sci & Engn, Guangdong Prov Key Lab Soil & Groundwater Pollut, Shenzhen 518055, Peoples R China
5.Univ South Carolina, Sch Earth Ocean & Environm, Columbia, SC 29208 USA
6.Univ Gothenburg, Dept Marine Sci, Gothenburg, Sweden

Correa, Rogger E.,Xiao, Kai,Conrad, Stephen R.,et al. Groundwater Carbon Exports Exceed Sediment Carbon Burial in a Salt Marsh[J]. Estuaries and Coasts,2021.

Correa, Rogger E..,Xiao, Kai.,Conrad, Stephen R..,Wadnerkar, Praktan D..,Wilson, Alicia M..,...&Santos, Isaac R..(2021).Groundwater Carbon Exports Exceed Sediment Carbon Burial in a Salt Marsh.Estuaries and Coasts.

Correa, Rogger E.,et al."Groundwater Carbon Exports Exceed Sediment Carbon Burial in a Salt Marsh".Estuaries and Coasts (2021).