Measuring Greenhouse Gases From Chambers: Relating Chamber Design to Microclimate and Flux.

The Kellogg Biological Station (KBS) Long-term Ecological Research (LTER) Program in SW Michigan studies the ecology of intensive field crop ecosystems as part of a national network of long-term ecological research sites.  The Department of Energy (DOE) Great Lakes Bioenergy Research Center (GLBRC) has also established a number of field–scale research sites at KBS to investigate the environmental sustainability of potential bioenergy cropping systems. The measurement of greenhouse gas (GHG) emissions is an essential component for evaluating the long-term impact of these agro-ecosystems on the environment. Intensive, year-round static and automated sampling is required to quantify the spatial and temporal variation of GHG emissions.

To ensure the integrity and compatibility of emissions data across the numerous treatments and management practices under investigation, robust and reproducible protocols for chamber construction and deployment, and sampling and analysis are essential. Our goal in this study was to investigate the microclimate conditions created by the deployment and presence of the various chamber types used in KBS field studies and relate these to GHG fluxes and concentrations. To do so we quantified the soil and air temperature, pressure, and moisture conditions that occurred over the 2012 growing season within and outside these chambers during closure and non-closure periods. Here we present data from these studies and relate differences in these parameters to the different chamber designs and environmental conditions encountered.