Riparian forests are known as hot spots of nitrogen cycling in landscapes. Climate warming speeds up the cycle. Here we present results from a multi-annual high temporal-frequency study of soil, stem, and ecosystem (eddy covariance) fluxes of N₂O from a typical riparian forest in Europe. Hot moments (extreme events of N₂O emission) lasted a quarter of the study period but contributed more than half of soil fluxes. We demonstrate that high soil emissions of N₂O do not escape the ecosystem but are processed in the canopy. Rapid water content change across intermediate soil moisture was a major determinant of elevated soil emissions in spring. The freeze-thaw period is another hot moment. However, according to the eddy covariance measurements, the riparian forest is a modest source of N₂O. We propose photochemical reactions and dissolution in canopy-space water as reduction mechanisms.

河岸森林被称为景观中氮循环的热点。气候变暖加速了这个循环。在这里，我们展示了来自欧洲典型河岸森林的 N ₂ O的土壤、茎和生态系统（涡流协方差）通量的多年高时频研究结果。热时刻（N ₂ O 排放的极端事件）持续了研究期间的四分之一，但贡献了一半以上的土壤通量。我们证明了 N _{2 的}高土壤排放O 不会逃离生态系统，而是在树冠中进行处理。中等土壤水分的快速含水量变化是春季土壤排放量增加的主要决定因素。冻融期是另一个热点。然而，根据涡度协方差测量，河岸森林是 N ₂ O的适度来源。我们建议将光化学反应和树冠空间水中的溶解作为还原机制。