Calibrated Parameters More Important than Two Dimensions for Phosphorus Modeling

The team found that CO2 carbon isotopic composition can be used to identify distinct natural and LLRW CO2 sources, the influence of root-zone moisture changes on shallow CO2 and CH4 dynamics, and how pore water interactions explain differences in CO2 and CH4 in the deep unsaturated zone. The results highlight the utility of using CH4 and CO2 as tracers of contaminant gases and to understand distributions of contaminants at the site, which include radiocarbon and volatile organic compounds. The role of the root zone and soil moisture in CO2 and CH4 biogeochemistry has substantial transfer value to similar arid sites.