Concepts

Human-induced nitrogen input that has doubled biologically-available nitrogen on Earth

Organic carbon derived from sedimentary rocks that is often poorly quantified and influences soil organic carbon composition, age, and stability

Spatial variability in biogeochemical processes and solute sources within watersheds, particularly between shallow soil zones and deeper groundwater zones

Areas of disproportionately high biogeochemical activity or export relative to surrounding landscape

Spatial variations in oxidation-reduction conditions within floodplain environments that can form within microsites, along textural transitions, or along the capillary fringe

The association of uranium with different solid-phase mineral forms that influences uranium mobility between solid and water phases

Zone of active mineral dissolution and precipitation reactions that advances through bedrock over time