关键词: 冻融作用, 氮水平, 氮形态, N₂O, 微生物机制

Abstract: N₂O is one of the three most important greenhouse gases, which could destroy the ozone layer. The N₂O loss from soil determines the status of soil nitrogen stock. In recent years, the response of soil N₂O emission to glo-bal change factors such as nitrogen deposition has attracted extensive attention. However, most studies are concentrated in the growing season, and less focuses on the non-growing season, especially in the freezing-thawing period. By reviewing the existing literature, we summarized the impacts of nitrogen deposition on soil N₂O emission in non-growing season, and discussed the possible mechanisms underlying the impacts of nitrogen deposition on soil N₂O emission in freezing-thawing period from the aspects of soil physical and chemical properties and soil microbiological characteristics. We pointed out the shortcomings of previous researches, and put forward to research direction, aiming at providing a reference for in-depth understanding of emission characteristics of soil N₂O and its driving mechanism under the background of global change, and for further taking effective measures to control soil N₂O emission.

Key words: freezing-thawing effect, nitrogen deposition level, nitrogen form, N₂O, microbial mechanism.