Quantifying Methane Ebullition from a Rewetted Fen at South Julius, Manitoba

Natural peatlands significantly contribute to atmospheric methane (CH4). While restoration of drained peatlands from horticultural peat extraction effectively increases their carbon sink potential, CH4 emissions ultimately increase. Rewetting practices create waterlogged and anaerobic conditions that foster increased methanogenesis. However, approximations of this increased methane production lack a comprehensive analysis. Traditional estimates of CH4 emissions often focus on diffusive and plant-mediated flux pathways, while limited research is available about the role of methane ebullition (bubbling) in post-extracted sites. Based on a rewetted fen at South Julius, Manitoba, my research focuses on quantifying the role of ebullition in methane emissions, given its highly variable nature and underestimation as a flux pathway. The data was collected from a restored peatland that is now permanently inundated and resembles a marsh-like plant community dominated by Typha species. Weekly methane fluxes were recorded from June to August 2025, using two complementary methods to estimate CH4 emissions. Closed chambers over varied vegetated collars and a floating chamber deployed on open water were used to capture both steady (diffusive and steady ebullitive) fluxes, as well as episodic ebullitive events. Using a LICOR LI-7810 field-portable greenhouse gas analyzer, methane fluxes were captured over approximately three-minute periods across several replicate plots throughout the wet site. Hydrological conditions, soil measurements and temperature readings were recorded to support the flux dynamics. Preliminary findings reveal the presence of steady and episodic ebullitive events from both the vegetated collars and open water, reinforcing the importance of recognizing ebullition as a relevant flux pathway. Further analysis of this data will contribute to the limited research on ebullition in restored peatlands and provide more accurate estimates of their overall contributions to atmospheric methane.