Chapter Five - Measurement of Carbon Dioxide, Methane, Nitrous oxide, and Water Potential in Soil Ecosystems

Abstract

New technologies in trace gas detection are revolutionizing our ability to study soil microbiological ecosystems. Field-deployable infrared-spectroscopy detectors capable of rapidly measuring multiple analyte gases simultaneously allow estimates of soil:atmosphere gas exchange and below-ground gas concentrations, and production dynamics across divergent ecosystems, creating opportunities to study interactions between microorganisms, soils, atmospheres, and global cycling, as well as interactions between different gases. The greenhouse gases CO₂, CH₄, and N₂O can be measured in the field and compared to each other to uncover links between the biochemical pathways responsible for the production and consumption of these gases. We have developed techniques using a nondestructive, Fourier-transform infrared detector under remote field conditions in three campaigns in the Canadian High Arctic to measure highly variable gas processes in soils.