Are Mangroves More Effective Carbon Sinks than Previously Thought? A Comparison of Sediment Ages Versus Radiocarbon Ages Seems to Suggest So.
Abstract
Over the last decade, coastal marine ecosystems have gained considerable attention for their ability to sequester large amounts of carbon dioxide from the atmosphere. These "blue carbon" sinks include mangrove forests, which cover only 0.5% of coastal land area across the globe, yet account for 15% of total carbon sequestration along coasts. However, the mechanisms controlling soil organic carbon (SOC) dynamics in these ecosystems have only recently been investigated. A combination of 210Pb and 14C chronologies allows for insight into SOC cycling. Whereas 210Pb dating allows for the determination of sediment accumulation rates, tracking the penetration of "bomb radiocarbon" gives insight into carbon cycling within the soil. Sediment cores from Ten Thousand Islands, Florida show the penetration of bomb radiocarbon into deeper sediment strata and 14C ages all with post-modern values (Fm> 1). These findings indicate mangroves are moving young, labile carbon from the atmosphere into older sediment strata and stabilizing it as POC for longer periods of time. If these results represent mangroves worldwide, the carbon sink associated with these ecosystems may be much more effective than previously thought.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.B23G2581S
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCESDE: 0428 Carbon cycling;
- BIOGEOSCIENCESDE: 0486 Soils/pedology;
- BIOGEOSCIENCESDE: 1630 Impacts of global change;
- GLOBAL CHANGE