Collaborative Research: Why Does the Efficiency of Methane Production Vary Dramatically Among Wetlands?

University Of Oregon Eugene, Eugene OR

Investigators

Abstract

The objective of this research is to understand the factors that control the production of the greenhouse gases carbon dioxide and methane in wetland soils under anaerobic (i.e., waterlogged with oxygen depletion) conditions in current and future climates. These two gases are the end products of a complicated, interlinked set of microbial processes during the anaerobic decomposition of soil organic matter, and the goal of this project is to understand the relative ratio at which these two gases are produced within the context of the larger anaerobic carbon cycle. Both field and laboratory experiments will be used to examine the chemical, environmental, and biological factors (including microbial community structure) that control the ratio at which these important greenhouse gases are produced in six wetlands in northern Michigan. These wetlands represent a broad range of conditions in terms of hydrology, chemistry, and plant community composition. The proportion of soil carbon that ends up as carbon dioxide and methane during anaerobic decomposition varies by several orders of magnitude among different types of wetlands, and the factors that control this variation are not well understood. Because methane is a much more potent greenhouse gas than carbon dioxide, the ratio at which these two gases are produced can have a substantial impact on the Earth?s climate system. Also, methane emissions from wetlands have been sensitive to climate change in the past and may have strong feedbacks to future human-induced climate change.