Context is everything: what controls nitrogen concentrations in U.S. streams

• Understanding the controls on nutrient concentrations is important for managing aquatic
  ecosystems. Our work focuses on understanding the biologically important summer N
  concentrations of rivers and streams across the US.
• Two national USEPA datasets are key to understanding the changes in stream water
  quality over time and how land management can affect stream total N concentration (TN)
  in the contiguous US.