Feng Yisong, Song Yanyu, Zhu Mengyuan, Li Mengting, Gong Chao, Luo Shouyang, Mei Wenkai, Feng Huanhuan, Tan Wenwen, Song Changchun
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; College of Geographical Science and Tourism, Jilin Normal University, Siping, 136000, China.
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China.
Water Res. 2025 Mar 15;272:122942. doi: 10.1016/j.watres.2024.122942. Epub 2024 Dec 9.
Wetlands are frequently regarded as weak carbon dioxide (CO) sinks, the largest natural sources of methane (CH), and weak sources of nitrous oxide (NO). Anthropogenic activities and climate change-induced nitrogen (N) enrichment may affect wetland carbon (C) and N cycling via soil microbes, consequently modifying the original greenhouse gas (GHG) emissions. However, the effects and mechanisms of the duration and rate of N inputs on wetland GHG emissions remain uncertain and controversial. Therefore, this study conducted an in situ field experiment to investigate the effects and driving mechanisms of long-term N enrichment on wetland GHG emissions throughout the 2023 growing season by using the static opaque chambers method. Soil microbial composition and function were also analyzed through metagenomic sequencing. The results showed that N enrichment significantly increased wetland CO emissions, which were associated with the abundance of microbial C-fixing functional genes and the soil C content. Although nitrogen enrichment tended to suppress CH emissions, the effect was not significant. High N enrichment created a powerful wetland NO source driven by the abundance of microbial nitrification function genes and microbial species. Vegetation influenced wetland GHG emissions by altering soil carbon content. This study elucidates the response mechanism of wetland GHG emissions to long-term nitrogen enrichment, thereby furnishing a theoretical basis for wetland conservation and nitrogen management.
湿地通常被视为较弱的二氧化碳（CO）汇、最大的甲烷（CH）天然源以及较弱的一氧化二氮（NO）源。人为活动和气候变化导致的氮（N）富集可能通过土壤微生物影响湿地碳（C）和氮循环，从而改变原始的温室气体（GHG）排放。然而，氮输入的持续时间和速率对湿地温室气体排放的影响及机制仍不确定且存在争议。因此，本研究通过静态不透明箱法进行了一项原位田间试验，以探究2023年生长季长期氮富集对湿地温室气体排放的影响及驱动机制。还通过宏基因组测序分析了土壤微生物组成和功能。结果表明，氮富集显著增加了湿地CO排放，这与微生物碳固定功能基因的丰度和土壤碳含量有关。虽然氮富集倾向于抑制CH排放，但其效果并不显著。高氮富集通过微生物硝化功能基因和微生物物种的丰度形成了强大的湿地NO源。植被通过改变土壤碳含量影响湿地温室气体排放。本研究阐明了湿地温室气体排放对长期氮富集的响应机制，从而为湿地保护和氮管理提供了理论依据。
