The role of priming effects on the conversion of blue carbon to CO2 in the coastal zone
EMSL Project ID
49505
Abstract
"Blue carbon," or organic carbon (OC) derived from and stored in coastal and marine environments, is recognized as an important OC sink within the global carbon cycle, particularly in mangrove, salt marsh, and seagrass settings. However, as sea level continues to rise, these blue carbon reserves will become increasingly sensitive to wetland erosion/loss, particularly in low relief coastlines such as the Florida coast where blue carbon is abundant. Although blue carbon can be stored in sediments for hundreds to thousands of years with little alteration, it is unclear how its reactivity will respond to remobilization into the marine environment. For example, in controlled laboratory experiments, the presence of highly reactive substrates (e.g. simple sugars and algal leachates) has been shown to cause the breakdown of terrestrially-derived dissolved organic carbon (TDOC) to occur ~4 times faster over a several week period and up to 75 times faster during the first 24 hours. This phenomenon is known as the "priming effect," and although it has been well-studied in soils, priming has been largely ignored by aquatic and marine communities until recently.
We propose to examine the influence of priming effects on the conversion of remobilized blue carbon to CO2 and unravel the underlying biological mechanisms for priming to occur based on controlled lab experiments using several types of blue carbon (e.g. peat and mangrove wood collected in FL) as a sole carbon source and with the co-addition of 13C-labeled priming substrates (e.g. sugars and algal biomass). We will track the rate of CO2 production and its stable and radio isotopic signature in order to determine the rate of blue carbon and priming substrate breakdown and collect samples to assess microbial community composition and the expression of targeted genes.
We plan to utilize the high-resolution spectrometry capabilities of EMSL to measure the net consumption/production of all detectable molecular formulae, evaluate changes in the abundance of proteins related to the community gene expression, and determine which metabolic pathways incorporate the 13C-labeled priming substrate. We propose to utilize the high-resolution spectrometry capabilities of EMSL to measure the net consumption/production of all detectable molecular formulae, evaluate changes in the abundance of proteins related to metagenomic/transcriptomic signatures, and determine which metabolic pathways incorporate the 13C-labeled priming substrate. Utilizing EMSL facilities is essential to advancing our understanding of the mechanisms driving priming effects and the potential positive feedback of sea level rise on blue carbon storage. This self-funded work will produce one or more high impact articles that will serve as the basis for a proposal to NSF Division of Environmental Biology to integrate results into a modeling framework and expanded field efforts to determine the large-scale implications of wetland erosion on global carbon cycling.
Project Details
Project type
FICUS Research
Start Date
2016-10-01
End Date
2018-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
Morrison E., M. Shields, T.S. Bianchi, Y. Liu, S. Newman, N. Tolic, and R.K. Chu. 2020. "Multiple biomarkers highlight the importance of water column processes in treatment wetland organic matter cycling." Water Research 168. PNNL-SA-146989. doi:10.1016/j.watres.2019.115153
Morrison E., N.D. Ward, A. Arellano, A. Ogram, T. Osborne, D. Vaughn, and Y. Liu, et al. 12/15/2017. "The role of priming effects on the conversion of blue carbon to CO2 in the coastal zone." Presented by Elise Morrison at AGU Fall Meeting, New Orleans, Louisiana. PNNL-SA-131167.
Morrison E., T.S. Bianchi, Y. Liu, A. Rivas-Ubach, N.D. Ward, and T. Osborne. 07/16/2019. "Do priming effects influence microbial turnover of blue carbon in the coastal zone?." Presented by E. Morrison at Gordon Research Conference: Chemical Oceanography, Holderness, New Hampshire. PNNL-SA-145272.
Ward N.D., E. Morrison, Y. Liu, A. Rivas-Ubach, T. Osborne, A. Ogram, and T.S. Bianchi. 2019. "Marine microbial community responses related to wetland carbon mobilization in the coastal zone." Limnology and Oceanography: Letters. PNNL-SA-134462. doi:10.1002/lol2.10101