Achievement

Over the past year, Rebecca Martin has completed an analysis of recent literature to assess the role of hydrologic pulse events, such as storms and snowmelt, in dissolved organic nitrogen (DON) export from rivers. Based on a working hypothesis that novel flowpaths through organic-rich landscape patches are active during pulse events, she predicted that pulse events enrich surface water with DON. Consequently, these events should be disproportionately important for annual DON flux. In general, this pattern appears to hold across a range of climates, and in systems with varying levels of human impact. This finding is significant, in that this pattern has not been previously established for a wide range of systems. Additionally, much focus has been on placed reducing N inputs to limit N-loading in surface water, but these results suggest that flowpaths may also play a key role in determining the form and magnitude of N that is exported.