Novel stable isotope and biomarker approaches to measuring methane emission in peat bogs (Ref IAP-17-48)

Methane (CH4) is a greenhouse gas that is 25-times more potent than CO2 at trapping heat at the Earth's surface. Methane emissions from peatlands represent {approximately equal to}10% of the total methane flux to the atmosphere. Under projected climate change scenarios, peats are expected to increase their contribution to atmospheric CH4. Methane is produced by methanogenic microorganisms in the permanently saturated lower layers of peat while it is consumed by methanotrophic microorganisms primarily in the upper aerobic layers. An understanding of the mechanisms for the mediation between methanogenic and methanotrophic activities is crucial to fully comprehend the processes that abate CH4 emissions from peatland. Diploptene is a methanotroph membrane lipid, whose concentration linearly increases with methane emission. This project aims to develop and assess a unique and novel stable isotope tool to elucidate how the carbon isotopic signature of this methanotroph biomarker is associated to methane availability as a carbon source in peat.