Climate change resulting from combustion of fossil fuels represents one of the great environmental challenges of the 21st century. Natural organic matter (NOM) is a major intermediary that links terrestrial and marine biomass to inorganic carbon in the atmosphere. Advances in analytical chemistry have greatly enhanced our understanding of the processes that control NOM reactivity and fate, but there has been little attention paid to the implications of these processes in the context of climate change. In this presentation we contrast the composition and optical properties of dissolved natural organic matter (DOM) in fens and bogs in a Northern Minnesota peatland using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and excitation emission matrix fluorescence spectroscopy with parallel factor analysis (EEM-PARAFAC). We identified a lipid-like, microbially-derived humic component that was abundant in fen porewater but much less so in bog porewater DOM (Fig. 1), suggesting that more CO2 and CH4 will be released from fens compared to bogs in response to global warming. FT-ICR MS data further suggested that oxygen-rich less aromatic molecules are selectively biodegraded. One important conclusion from this study is that EEM data coupled with ultrahigh resolution FT-ICR mass spectrometry has the potential to provide significant molecular-based information on DOM composition that will support efforts to better understand the diagenetic status of DOM in peatlands, particularly in response to climate change.

Molecular composition and fluorescence properties of natural organic matter in a northern peatland: Implications for climate change

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.