Glaser 9652692 Chemical and Physical Controls on Transport Processes in Large Peatlands Northern peatlands represent an important source and sink for greenhouse gases. Attempts to estimate these fluxes of greenhouse gases between the atmosphere and biosphere and relate them to global change, however, are limited by uncertainties regarding the material properties of peat. These parameters are difficult to quantify by traditional methods, which alter the delicate fabric of peat and are incapable of resolving the three dimensional (3D) structure of peat pores. Current estimates for the porosity of peat deposits and their release of greenhouse gases may therefore have errors in excess of several orders of magnitude. A new approach for determining the fine structure of porous materials is Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI). The investigators will use these techniques in conjunction with visualization software to quantify 1) the 3D pore structure, 2) structural changes produced by laboratory experiments, and 3) production of greenhouse gases in peat cores. These values can then be used to model the role of peatlands in global change.