Grant: Research Tools and Instruments - Category 1 (<$150,000)

Field studies are sorely needed to establish the actual, rather than theoretical, in-situ response of soil carbon stocks to climate change.  The major challenge in this area of research is resolution and/or control of variables to hold parameters (e.g. moisture) constant for accurate assessments of driving and limiting factors that contribute to loss or storage of soil organic matter.  Another in-situ challenge in the area of soil carbon research lies in the quantification of decomposition rates among different carbon pools, which is critical since deeper, recalcitrant soil organic matter is thought to hold the majority of long-term sequestration capacity. By using a subsurface, high-temporal resolution monitoring methodology in conjunction with microclimatic manipulation techniques borrowed from contaminant bioremediation studies, it is possible to test new questions in soil carbon stability, namely the effect of the numerous physical parameters other than temperature on soil carbon loss in natural settings.  To date, an in-situ experimental approach has not been used to explicitely test the significance of these physical factors, but it is known that they act in many areas (especially high latitudes) to stabilize soil carbon and protect it from decomposition.  I propose to construct four one-off systems for automated control and high frequency monitoring of soil decomposition rates in response to manipulations of soil physical factors, in particular moisture, oxygenation, and temperature.  In effect, each of these systems constitutes a "field laboratory".  I am requesting four systems to perform manipulative experiments in each of Atlantic Canada's major forest biomes - Boreal, Sub-Boreal, Acadian Forest and Great-Lakes St. Lawrence.