College of Geographic Science and Tourism, Jilin Normal University, Siping, 136000, China.
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China.
Environ Sci Pollut Res Int. 2024 Sep;31(43):55774-55787. doi: 10.1007/s11356-024-34877-4. Epub 2024 Sep 7.
Nitrogen is the most limiting nutrient in wetland ecosystems. Changing in nitrogen nutrient status has a great effect on wetland carbon and nitrogen cycling. However, there is much uncertainty as to wetland greenhouse gas emissions response to nitrogen inputs in China. In this study, we synthesized 177 paired observations from 27 studies of greenhouse gases emissions related to nitrogen additions across wetland in China. The results showed nitrogen inputs significantly contributed to wetland carbon dioxide (CO) and nitrous oxide (NO) emissions but had no significant effect on methane (CH). We further analyze the relationship between greenhouse gases emissions and soil properties, climate factors under nitrogen inputs. Regression analyses introducing explanatory variables showed that high nitrogen inputs (12 g N m yr-24 g N m yr) contributed more significantly to wetland CO and NO emissions. Compared to other wetland types, alpine peatlands have a greater impact on CO and NO emissions following nitrogen input. In addition, high altitude (> 1500 m and ≤ 3500 m) could promote wetland CO and NO emissions more significantly after nitrogen input, but ultra-high altitude (> 3500 m) reduced CO emissions. CO and NO emissions were more significantly promoted when mean annual temperature (MAT) was positive, and CO emissions increased with increasing mean annual precipitation (MAP). Wetland CO emissions can be significantly promoted when soil is acidic, while NO emissions can be significantly promoted when soil is alkaline. NO emissions increased with increasing of soil total nitrogen (TN) and soil organic carbon (SOC) contents. These findings highlight the characteristics of wetland greenhouse gas emissions following nitrogen input, and improve our ability to predict greenhouse gas emissions and help meet carbon neutrality targets.
氮是湿地生态系统中最受限制的养分。氮养分状况的变化对湿地碳氮循环有很大影响。然而，中国湿地温室气体排放对氮输入的响应存在很大的不确定性。在这项研究中，我们综合了 27 项研究中涉及中国湿地氮添加的温室气体排放的 177 对观测结果。结果表明，氮输入显著促进了湿地二氧化碳（CO）和氧化亚氮（NO）的排放，但对甲烷（CH）没有显著影响。我们进一步分析了氮输入下温室气体排放与土壤性质、气候因素之间的关系。引入解释变量的回归分析表明，高氮输入（12 g N m-2~24 g N m-2）对湿地 CO 和 NO 排放的贡献更大。与其他湿地类型相比，高山泥炭地在氮输入后对 CO 和 NO 排放的影响更大。此外，高海拔（> 1500 m 且≤ 3500 m）在氮输入后更能显著促进湿地 CO 和 NO 排放，但超高海拔（> 3500 m）降低了 CO 排放。氮输入后，当年平均气温（MAT）为正，CO 排放随着年平均降水量（MAP）的增加而增加。当土壤呈酸性时，湿地 CO 排放可以显著增加，而当土壤呈碱性时，NO 排放可以显著增加。NO 排放随着土壤全氮（TN）和土壤有机碳（SOC）含量的增加而增加。这些发现突出了氮输入后湿地温室气体排放的特点，提高了我们预测温室气体排放的能力，有助于实现碳中和目标。
