John Bargar
Title: A National Molecular Observation Network (MONet) for Regional Soil Function
Abstract: While carbon and essential nutrients are the currency of healthy ecosystems, we have poor mechanistic understandings of their chemical processing pathways through soils and natural waters, and of how these molecular processes aggregate across regions. The existing state of knowledge does not adequately support model development. Big data are needed at regional scales to sharpen this picture. To provide regional scale soil carbon. molecular data, EMSL is leading the development of a national Molecular Observation Network (MONet) of environmental sampling and sensing sites for interrogating molecular-level information on the composition and microstructure of soil, water, and resident microbial communities. EMSL users, partners, and citizen scientists from around the US will have access to a high-throughput analysis workflow that will produce high-resolution data on carbon molecular composition, soil pore network structure, hydraulic properties, and microbial metagenomes. High-resolution molecular and pore structural data will complement soil measurements performed by existing networks such as Ameriflux and NEON. This program will leverage samples, insights, and the scientific expertise of the EMSL user community. Data will be stored in a cutting-edge FAIR database that will be accessible with tools designed to facilitate access and modeling applications.
Short bio: John Bargar has more than 25 years experience in the field of biogeochemistry. He is currently the Science Area lead for the Environmental Transformations and Interactions group at the Environmental Molecular Sciences Laboratory. He earned his Ph.D. in Environmental Geology from Stanford University. His research interests are in biogeochemical transformations and transport of metal micronutrients in terrestrial ecosystems and their impacts on carbon fate and transport.
Tamas Varga
Title: Examples of EMSL Research with Synchrotron-Based Investigations of Plant and Soil Systems
Abstract: The Environmental Molecular Sciences Laboratory (EMSL) is a national scientific user facility at Pacific Northwest National Laboratory (PNNL). EMSL looks to extend its integrated suite of capabilities through collaboration with other national user facilities such as the APS. Structural and chemical imaging bio/geochemical systems seem to be a sweet spot for collaboration. Two projects will be highlighted where beamline capabilities provided unique insight.
In the first example, x-ray fluorescence spectromicroscopy at the APS and microtomography at the ALS were used to visualize and better understand phosphorous uptake in poplar trees. In the second example, scanning transmission x-ray microscopy combined with x-ray absorption near edge structure helped us investigate soil mineral – soil organic matter (SOM) interactions in an alkaline soil from Washington state. Ca mineral–organic matter bridges were found to play a critical role in the stabilization/degradation of SOM and mineral. Finally, a current project focused on connecting the pore structure of different soil types to the distribution and transport of SOM will be discussed and the opportunity for using the synchrotron will be pointed out.
Short bio: Tamas Varga is a materials scientist at the Environmental Molecular Sciences Laboratory. He earned his Ph.D. in Chemistry from Georgia Institute of Technology. His research focuses on the application of x-ray imaging and spectroscopy methods to the studies of biological, geological, and other materials and problems. His current focus is soil biogeochemical processes and their relation to soil porous structure.