Generally Reduced Sink Capacity of Upland Soils for Atmospheric Methane Over the Past Three Decades (1993–2022)

作者：Zhaoxin Li, Yanmeng Shang, Chao Wang, Jinyang Wang, Xiao-Bo Liu, Fadong Li, Gang Chen, Hefa Cheng, Jianwen Zou, Shuwei Liu · 发表于：Global Change Biology · 年份：2025 · DOI：10.1111/gcb.70248 · 被引用次数：6 · 研究领域：Atmospheric and Environmental Gas Dynamics、Climate change and permafrost、Peatlands and Wetlands Ecology

ABSTRACT Upland soils act as the second largest and the only manageable sink of atmospheric methane (CH 4 ). Quantifying spatiotemporal patterns of the net CH 4 exchange between upland soils and atmosphere is critical for refining global CH 4 budget estimates and developing climate mitigation strategies. However, the global CH 4 budget in upland soils remains highly uncertain due to incomplete understanding of the shifts in the source or sink role of upland soils for CH 4 under climate change. In this study, we generated high‐resolution global maps of CH 4 fluxes from upland soils by integrating field CH 4 flux measurement data spanning over the period of 1993–2022 using machine learning models. Collectively, upland soils exhibited a generally reduced sink capacity for atmospheric methane over the past three decades. Cropping uplands presented a shift from a weak sink to a source, and grassland soils changed from a sink to a strong source of CH 4 . The sink capacity of forest soils for CH 4 sharply decreased by 68.8% over the past three decades, while tundra upland soils acted as a consistent source of CH 4 , with a decrease of 55.3% since 1993. The combined effects of changes in precipitation and temperature can explain more than 70% of spatiotemporal variations of CH 4 fluxes in upland soils. Our findings provide a new perspective on the spatiotemporal patterns of CH 4 fluxes in global upland soils, which update the role of upland soils in the global CH 4 budget, particular...