64-14 What about the uncertainty? Insights to soil organic carbon stocks in mangrove forest of the southwest Florida.

Session: Emerging Voices in Soil and Paleosol Science (Posters)

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To quantify soil organic carbon (SOC) in blue carbon ecosystems (BCEs), three variables need to be quantified: dry bulk density (DBD), percentage of organic carbon (%OC), and soil depth. Typically, measurements are made within one soil core. Depth of soil is either measured, estimated, or confined to a conventional definition. Despite normally extrapolating carbon stock estimates over the area of a particular site, researchers seldom account for the uncertainty of the depth of the organic soil layer in these systems. Here, we examine the influence of uncertainty of each of the measured variables on the final SOC calculation. Cores were collected in eight mangrove sites to obtain values of %OC and dry bulk density, and analytical uncertainty was determined in the laboratory. To constrain depth uncertainty, we performed random radial sampling with five soil probes around each core. Each probe was measured and the soil character described based on the presence of peat, mud, sand and shell material. We incorporated site and analytical uncertainty calculations in the organic soil layer depth and the quantification of the total soil OC stock respectively. We found that the main contributor of uncertainty is in the DBD with around 62.5% followed by the %OC (25%), and depth (12.5%). This order could change if different sources of uncertainty (like calculating %OC from loss on ignition data or calculating DBD from grayscale imagery data) are included or if a site has more variable peat depth. Improved understanding of uncertainty contributions to SOC stock estimations in BCEs not only helps pinpoint where experimentation can be improved, it also aids in comparative studies of carbon stock. This is particularly important for comparing natural and restored/created BCEs, where accurate and precise data are important in climate mitigation strategies. Uncertainty is also an important variable to consider in calculating emission reductions, or new carbon capture potential, especially when using restored and created BCEs as natural climate change mitigation solutions.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-10537

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