N2O emission and its influencing factors in subtropical streams, China

Abstract Background Rivers and streams are one of the primary sources nitrous oxide (N 2 O) which is an important greenhouse gas with great global warming potential. Yet, over past century, human activities have dramatically increased reactive nitrogen loadings into consequently led to N O emission from river ecosystems. Here, we carried out a study in two subtropical rivers, i.e., Jinshui River Qi slight intense disturbance their respective catchments China. The intended explore spatial variability seasonality emissions, relative importance physicochemical variables, nitrification denitrification potentials, functional genes abundance influencing emissions. Results concentration, saturation, flux peaked high flow season. saturations, downstream were significantly higher than that other areas normal low seasons. concentration was positively correlated water temperature, NO 3 − , DOC, negatively NH 4 + DOC/NO (the ratio dissolved organic carbon water), potential rate season, but not abundance. Both rivers had lower saturation many freshwater systems, EFr-5 factor for river) recommended values IPCC. Conclusions While moderate emissions systems normally elevated summer, those disturbance. Physicochemical variables good indicators