Nitrous Oxide Emissions from Drying Streams and Rivers

Streams and rivers are suffering more extreme and prolonged low flows than those naturally occurring without human intervention with potential relevant worldwide effects on the production of nitrous oxide (N2O), a greenhouse gas 300 times more potent than carbon dioxide. Here, we address the question of whether droughts and management-induced low flows increase riverine N2O emissions causing positive feedback in response to climate change. Supported by field data, we model riverine N2O emissions for decreasing mean summer flows in a forested and agricultural watershed under chemostatic and chemodynamic dissolved inorganic reactive nitrogen (DIN) concentrations. Our results demonstrate that total N2O emissions decrease with increasing low flow severity in both watersheds regardless of DIN scenario; which imparts a form of climate resilience.