Coupling effect of temperature and ammonia on N2O emission in surface water

The increase of nitrous oxide emission has become a worldwide problem. The emission of nitrous oxide from water body increased with the increase of N inputs. Our study analyzed the roles of temperature and ammonia in N2O emission through quantification of nitrogen transformation and related functional genes. The results showed that the abundance of ammonia oxidizing archaea and denitrifiers positively correlated to N2O emission in water. Structural equation model revealed ammonia content had no direct effect on N2O emission, however, high temperature and nitrification directly accelerated the release of N2O. In addition, nitrification process also increased the release of N2O indirectly through promoting abundance of denitrifiers and nitrite content. © 2019, Editorial Board of China Environmental Science. All right reserved.