Tracking Past Methane Dynamics from Sphagnum Peatlands

Speaker: Dr. Tim Daley, University of Plymouth
Series: Quaternary Discussion Group (QDG)

Peat archives are widely used to reconstruct past hydroclimate, but they may also preserve evidence of past methane cycling and ecosystem carbon processing. This talk explores how combining palaeoecological, biomarker and isotope approaches can reveal past methane dynamics in a late-Holocene peat sequence from northern England. During a ~100-year interval of very wet conditions, Sphagnum δ¹³C departs markedly from its expected relationship with hydrology, coinciding with increased abundance and strongly depleted δ¹³C of a biomarker consistent with methanotrophic activity. Together, these signals support episodic recycling of methane-derived carbon into Sphagnum biomass. Placed within a broader relationship between Sphagnum δ¹³C and water-table depth, the results provide a framework for distinguishing hydrological isotope effects from changes in carbon source, offering a new way to reconstruct how carbon is processed and recycled within peatlands through time.