GCE IV - Key Finding in 2023

Advancing C synthesis

There is considerable interest in the role that coastal ecosystems play in the global C cycle, given their rates of primary production and potential for long-term soil C storage. However, ascertaining the net effect of wetlands on coastal carbon dynamics requires accurate accounting of stocks and fluxes of dissolved and particulate organic and inorganic forms of carbon. To address this, GCE investigators are involved in several efforts to catalogue and synthesize estuarine and wetland C data. GCE investigator P. Medeiros was part of a group compiling a global database of dissolved organic matter measurements in coastal waters (Lonborg et al.in review); C. Craft contributed to a global dataset of soil organic C in tidal marshes (Maxwell et al. 2023); W-J. Cai was part of a synthesis paper that used data from 738 studies to estimate greenhouse gas fluxes from both estuaries and coastal wetlands that resulted in downward revisions of both C-fixation in wetlands and greenhouse gas emissions in estuaries (Rosentreter et al. 2023). Finally, A. Spivak is part of the soil carbon working group facilitated by the NSF-supported coastal Carbon Research Coordination Network, which has created a centralized, standardized database that can be used for C stock assessments (Holmquist et al, in review). One example of the benefits of these efforts is the ability of Sharma et al. (2023) to retrieve 261 measurements of soil organic C (SOC) as input for a remote sensing (Fig. 2). They are using these observations as ground-truth in the development of a machine learning model that can be used to predict subsurface (depth) SOC in tidal wetlands.




Fig. 2 Distribution of 261 point locations of SOC measurements in the southeastern coastal United States. These points, collected between 2007 and 2018, were retrieved from the Coastal Blue Carbon Network database. (Source: Sharma et al. 2023)