Testing an Ebullition Model Shows the Importance of Peat Structure in The Florida Everglades

In this study, we tested a computer model for gas ebullition and storage in peat soils that simulates peat structure against a suite of field measurements in peat soils of the Florida Everglades. Physical properties of peat (porosity, thickness, and humification) and estimated methane gas production values were measured in the field and used as model input. Ebullition events from the model were compared to those observed in the field using time-lapse cameras and gas traps, with both field and modeled patterns showing similar behavior in terms of: 1) frequency distribution of number of ebullition events per time; and 2) the magnitude of ebullition events. Gas storage values in the model compared well with those measured in the field in the laboratory using ground penetrating radar (GPR) methods. The model also compared well to gas storage values with depth in a peat monolith studied in the lab. These results suggest that the internal structure of the peat matrix is a primary control on ebullition in peat soils from the Everglades.