Please consider submitting to this excellent session on redox dynamics at the Goldschmidt 2017 conference in Paris, France (August 13th-18th).
Abstract submission deadline is April 1st, 2017 (23:59 EST).
11e: How Spatial and Temporal Redox Dynamics Shape Biogeochemistry in Soils and Sediments Across Scales
Keynote Speaker: Professor Philippe Van Cappellen (University of Waterloo, Canada)
Dynamic redox conditions and redox interfaces are a major determinant of microbial activity and mineral reactivity in sediments and soils, but are poorly described by biogeochemical models of contaminant degradation, nutrient dynamics, or carbon cycling. In near-shore, wetland and upland systems, redox conditions may change rapidly (daily, weekly or seasonally), due to high biological oxygen production and demand, changing moisture content or water table levels, and the availability of reductants and oxidants, creating ‘hot moments’ of redox disequilibrium. The temporal dynamics of hydrologic flow conditions intersect with soil and sediment structure to create a heterogeneous matrix (e.g., hot spots) of spatiotemporal redox gradients in subsurface environments. These dynamic redox conditions set the stage for rapid C, Fe, S, P, N cycling and can alter mineral reactivity and the physiochemical habitat, metabolic pathways and nutrients available to microorganisms. These dynamics promote discontinuous or ‘non-linear’ responses that may hinge on novel mechanisms in redox transformations. We invite contributions addressing these issues and questions of how shifts in redox dynamics, including natural organic matter redox transformations, affect mineral reactivity, microbial abundance and activity in space and time, specifically focusing on the implications for the fate of nutrients (N, S, and P), metals (e.g., Fe and Mn), pollutants (e.g., As and Cr), and greenhouse gases (CO2, CH4, N2O, etc.). This session seeks to bring together scholars exploring questions from a range of disciplines using observational, experimental, and theoretical approaches