Yang Qu, Gao Wei-Feng, Liu Feng-Qin, Wang Wen-Feng, Ma Jian-Hua, Xu Zhuo, Liang Hong, Gao Da-Wen
School of Forestry, Northeast Forestry University, Harbin 150040, China.
State Key Laboratory of Urban Water Resource and Water Environment, Harbin Institute of Technology, Harbin 150090, China.
Huan Jing Ke Xue. 2019 Feb 8;40(2):876-884. doi: 10.13227/j.hjkx.201806132.
Wetlands are important sources and sinks for NO. Exploring the role of NO emissions in saline-alkali wetlands has great significance in understanding the nitrification mechanism of NO production and assessing the role of saline-alkali wetlands in the greenhouse effect. The present study examined the NO fluxes and environmental factors of a typical Zhalong reed wetland during the growing season. The results suggested that the NO fluxes tended to decrease in volatility, with the highest value in mid-July. The mean flux of NO was (37.49±15.75) μg·(m·h), indicating that the typical Zhalong reed wetland was a source of NO. The NO fluxes exhibited a significantly positive correlation with soil temperature at different depths (<0.05), and the impact of the upper soil temperature on NO flux was higher than that of deep soil. In the flooding period, the relationship between NO fluxes and water table depth was negatively correlated (<0.05). Meanwhile, the TOC and TN contents were lower, and the NO flux was significantly positively correlated with the NH-N content in the 0-40 cm soil layer (<0.05), but it was not related to NO-N content. Nitrification was stronger than denitrification. There was a significant positive correlation between ammonia-oxidizing bacterial activity and soil temperature in 0-20 cm layer (<0.01). Additionally, the activity of ammonia-oxidizing bacteria also presented significantly positive linear correlation with the NO fluxes (<0.001), which indicated that the release of NO in saline-alkali wetlands was greatly affected by nitrification.
湿地是一氧化氮的重要源和汇。探究盐碱湿地中一氧化氮排放的作用，对于理解一氧化氮产生的硝化机制以及评估盐碱湿地在温室效应中的作用具有重要意义。本研究考察了典型的扎龙芦苇湿地在生长季的一氧化氮通量及环境因子。结果表明，一氧化氮通量波动呈下降趋势，7月中旬达到最高值。一氧化氮的平均通量为(37.49±15.75)μg·(m·h)，表明典型的扎龙芦苇湿地是一氧化氮的一个源。一氧化氮通量与不同深度的土壤温度呈显著正相关(<0.05)，上层土壤温度对一氧化氮通量的影响高于深层土壤。在淹水期，一氧化氮通量与地下水位深度呈负相关(<0.05)。同时，总有机碳和总氮含量较低，0至40厘米土层中一氧化氮通量与铵态氮含量呈显著正相关(<0.05)，但与硝态氮含量无关。硝化作用强于反硝化作用。0至20厘米土层中氨氧化细菌活性与土壤温度呈显著正相关(<0.01)。此外，氨氧化细菌活性与一氧化氮通量也呈显著正线性相关(<0.001)，这表明盐碱湿地中一氧化氮的释放受硝化作用影响很大。
