Increased delivery of nitrogen due to land use change has led to increased eutrophication, habitat loss in estuaries, and contamination of drinking water supplies. Dr. Kaushal will discuss changes in the fate and transport of nitrogen in streams and rivers in response to a changing landscape in the Chesapeake Bay watershed. He will also show how increasing land-use change and climate variability can interact to amplify watershed nitrogen exports and implications for forecasting nitrogen exports across human-dominated landscapes. For development of decision support tools, he will show how sources of nonpoint nitrogen pollution (atmospheric, fertilizer, septic, wastewater) can be traced from headwaters to large rivers using stable isotope tracers. In order to manage the nitrogen cycle, he will describe research investigating strategies for increasing the adaptive capacity of watersheds to climate via stormwater management, stream and floodplain restoration, and advanced wastewater treatment. Finally, he will briefly discuss future challenges for forecasting nitrogen dynamics in response to rising temperatures, long-term hydrologic variability, and comparisons with other emerging contaminants.