中国江河氧化亚氮的排放及其影响因素

Nitrous oxide (N₂O) is a potent greenhouse gas with a long residence time, and it is deemed as one of the foremost destroyers of stratospheric ozone in the 21^st century. Climate predictions necessitate a full and robust account of natural and anthropogenic greenhouse gas emissions including N₂O. Inland waters are important sources for N₂O emissions, and N₂O emissions from streams and rivers may increase gradually year by year due to the increased anthropogenic input of reactive nitrogen. In this review, we summarized available data of dissolved concentrations and fluxes of N₂O from ten watersheds in diverse climate zones in China. The results showed that the dissolved N₂O concentrations ranged from 0.3 to 1591 nmol•L^-1 and the fluxes ranged from -12.2 to 2262.1 μmol•m^-2•d^-1, which were generally comparable to those of other lotic settings around the world. We also analyzed the mechanisms regarding the fluvial production and emission of N₂O, and discussed the controlling factors including dissolved inorganic nitrogen, dissolved oxygen, organic carbon as well as hydrological, topographic and meteorological conditions. Furthermore, N₂O emissions from streams and rivers under a changing environment have been discussed.