State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Environ Pollut. 2023 Oct 1;334:121848. doi: 10.1016/j.envpol.2023.121848. Epub 2023 May 25.
Increased nitrogen (N) deposition has a great impact on soil greenhouse gas (GHG) emissions, and numerous studies have revealed the individual effects of N addition on three major GHGs (CO, CH, and NO). Nevertheless, quantitative evaluation of the effects of N addition on the global warming potential (GWP) of GHGs based on simultaneous measurements is needed not only to better understand the comprehensive effect of N deposition on GHGs but also for precise estimation of ecosystem GHG fluxes in response to N deposition. Here, we conducted a meta-analysis using a dataset with 124 simultaneous measurements of the three major GHGs from 54 studies to assess the effects of N addition on the combined global warming potential (CGWP) of these soil GHGs. The results showed that the relative sensitivity of the CGWP to N addition was 0.43%/kg N ha yr, indicating an increase in the CGWP. Among the ecosystems studied, wetlands are considerable GHG sources with the highest relative sensitivity to N addition. Overall, CO contributed the most to the N addition-induced CGWP change (72.61%), followed by NO (27.02%) and CH (0.37%), but the contributions of the three GHGs varied across ecosystems. Moreover, the effect size of the CGWP had a positive relationship with N addition rate and mean annual temperature and a negative relationship with mean annual precipitation. Our findings suggest that N deposition may influence global warming from the perspective of the CGWP of CO, CH, and NO. Our results also provide reference values that may reduce uncertainties in future projections of the effects of N deposition on GHGs.
氮（N）沉降增加对土壤温室气体（GHG）排放有很大影响，许多研究已经揭示了 N 添加对三种主要 GHG（CO、CH 和 NO）的单独影响。然而，需要基于同时测量来定量评估 N 添加对 GHG 全球变暖潜势（GWP）的影响，不仅要更好地了解 N 沉降对 GHG 的综合影响，还要精确估计生态系统 GHG 通量对 N 沉降的响应。在这里，我们使用包含 54 项研究中 124 次三种主要 GHG 同时测量的数据集进行了荟萃分析，以评估 N 添加对这些土壤 GHG 的综合全球变暖潜势（CGWP）的影响。结果表明，CGWP 对 N 添加的相对敏感性为 0.43%/kg N ha yr-1，表明 CGWP 增加。在所研究的生态系统中，湿地是相当大的 GHG 源，对 N 添加的相对敏感性最高。总体而言，CO 对 N 添加引起的 CGWP 变化的贡献最大（72.61%），其次是 NO（27.02%）和 CH（0.37%），但三种 GHG 的贡献在不同的生态系统中有所不同。此外，CGWP 的效应大小与 N 添加率和年平均温度呈正相关，与年平均降水量呈负相关。我们的研究结果表明，从 CO、CH 和 NO 的 CGWP 角度来看，N 沉降可能会影响全球变暖。我们的结果还提供了参考值，可能会降低未来对 N 沉降对 GHG 影响预测的不确定性。
