Abstract

We have used a portable, battery-powered quadrupole mass spectrometer to measure the relative concentrations of carbon dioxide (CO₂), methane (CH₄), and water vapor in soils of the Coconino National Forest. In particular, we have compared the soil gas levels in regions of the forest that have been untouched with regions that have suffered wildfire damage. With some exceptions, our results tend to indicate that both the soil CO₂ concentration and the soil CH₄ concentrations decrease somewhat as the severity of the forest damage increases through the timing of the fire and subsequent forest regrowth. In some cases, soil water vapor content appears to have played a significant role in the concentrations of these gases as well. Further measurements over longer periods of time are required to more exactly quantify the role played by many different variables in the local concentrations of important forest soil gases.