Conference presentation
Blue carbon oxidation revealed by radiogenic and stable isotopes in a mangrove system
ASLO Aquatic Sciences Meeting (Honolulu, USA, 26/02/2017 - 03/03/2017)
02/03/2017
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Abstract
Mangroves are among the most carbon-rich ecosystems on Earth. Most of the carbon is sequestered in sediments and assumed to be stable over long time scales. Here we assess whether century-old buried carbon may be remineralized and exported by measuring Δ14C in the exported dissolved inorganic carbon (DIC) as well as sediment Δ14C profiles in a subtropical mangrove. Porewater exchange released isotopically depleted, old DIC to surface waters. Keeling plots revealed the surface water DIC source had a δ13C-DIC value of -29.4 ±1.9‰ and Δ14C-DIC value of -73±9‰ (~555 years BP). The respired and exported carbon comes from an average depth of ~38 cm, equivalent to ~ 100 years of sediment accumulation. Therefore century-old buried carbon is still susceptible to remineralization and tidal export via porewater exchange from mangroves. We suggest that the time scales over which blue carbon sequestration is assessed should consider carbon losses via porewater exchange.
Details
- Title
- Blue carbon oxidation revealed by radiogenic and stable isotopes in a mangrove system
- Creators
- Damien T Maher - Southern Cross UniversityIsaac R Santos - Southern Cross UniversityKai Schulz - Southern Cross UniversityMitchell Call - Southern Cross UniversityGeraldine E JacobsenChristian J Sanders - Southern Cross University
- Conference
- ASLO Aquatic Sciences Meeting (Honolulu, USA, 26/02/2017 - 03/03/2017)
- Identifiers
- 991012845997802368
- Academic Unit
- Faculty of Science and Engineering; Centre for Coastal Biogeochemistry; National Marine Science Centre; School of Environment, Science and Engineering; Science
- Resource Type
- Conference presentation