Carbon dioxide and methane efflux in burned versus unburned soils of western and central South Dakota

Carbon dioxide (CO₂) and methane (CH₄) are two greenhouse gases of concern in the Earth's atmosphere. Anthropogenic actions are projected to have aided the increase of both gases to the atmosphere over the past century, causing their sources to become greater than their sinks. Because soil is the largest terrestrial source of carbon dioxide to the atmosphere and the only biological sink of methane, it is important to know how land management practices are affecting natural cycles of each gas. This study focuses on prescribed burning practices in the Black Hills of South Dakota, a Ponderosa Pine dominated forest ecosystem, as well as surrounding grassland regions in western and central South Dakota. At each site, soil samples and gas flux measurements using a static chamber method were taken in both burned and unburned environments at weekly intervals over a period of several months. Soil flux of both CO2 and CH4 were analyzed using gas chromatography; additional soil measurements obtained from sampling included temperature, moisture, and biomass. Results from the measured variables were compared between the burned and unburned environment at each selected site.