Organic carbon characterization in a warming coastal wetland
EMSL Project ID
50205
Abstract
Coastal wetlands are global hotspots of carbon storage, but the future carbon stock stability of coastal wetlands is uncertain as data are lacking on responses to factors such as warming and elevated carbon dioxide that perturb the complex feedbacks that drive soil carbon sequestration. Although we know that wetland plant activity regulates soil redox potential, carbon cycling, and methane emissions, surprisingly few data exist that mechanistically couple plant responses to changes in microbial electron donors and acceptors. Such interactions are particularly complex in coastal wetlands, due to abundant supplies of the alternative electron acceptor sulfate. Through collaboration with EMSL, we will be able to gain a molecular-level understanding of the poorly-characterized belowground carbon processes that feedback to the climate system, with a focus on the coupled plant and microbial responses to warming and elevated carbon dioxide that regulate carbon preservation.The Salt Marsh Accretion Response to Temperature eXperiment (SMARTX) was established with DOE funding and is dedicated to understanding the ecosystem-scale consequences of elevated carbon dioxide and warming in tidal wetlands at the coastal terrestrial-aquatic interface. To date, warming is increasing belowground growth, a response that is amplified by elevated carbon dioxide. These vegetation effects will likely alter microbial metabolism, but we have not yet been able to link plant and microbial processes to soil organic matter decomposition. We hypothesize that warming and elevated carbon dioxide are simultaneously increasing both aerobic respiration through increased belowground molecular oxygen (O2) input, and anaerobic microbial respiration through increased carbon inputs from root exudates. At EMSL, we propose to use FTICR-MS to calculate the nominal oxidation state of carbon , which will reflect aerobic respiration rates, and to use NMR and GC-MS to identify metabolites, which will reflect changes in microbial metabolism.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2018-10-01
End Date
2021-06-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members