Date of Award

Fall 2012

Project Type

Thesis

Program or Major

Earth Sciences: Geochemical Systems

Degree Name

Master of Science

First Advisor

Ruth K Varner

Abstract

Molecular hydrogen (H2) is produced and consumed through syntrophic organic matter decomposition in soil. The purpose of this study was to determine if organic-rich soils can become a temporary source of H2 to the atmosphere under anoxic conditions and the release of labile carbon.

H2 was generally consumed at the subarctic peatland, but the net H2 uptake decreased as site moisture increased from the dry palsa site to the wet Eriophorum site. The dissolved H 2 concentrations suggest that methanogenesis is the predominant decomposition pathway at depth and other decomposition processes or plant-mediated transport influence concentrations closer to the surface.

The incubation of boreal forest soils under a range of temperatures, soil moistures, and substrate availabilities indicated that warm, dry soils have the highest H2 emission to the headspace. However, it appeared that the incubations did not become anoxic during the incubation period.

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