1,2,3,6,7,1,8- 1Peking University, College of Urban and Environmental Sciences, China (2301112206@stu.pku.edu.cn)
- 2Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, P.R. China
- 3Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Aas, Norway
- 4Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, School of Life Sciences, Fudan University, Shanghai 200438, China.
- 5Institute of Eco-Chongming (IEC), East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China.
- 6Earth Systems Research Center, University of New Hampshire, Durham, NH, 03824 USA
- 7CAS Key Laboratory of Forest Ecology and Silviculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, P.R. China
- 8National Key Laboratory of Water Disaster Prevention, Jiangsu Key Laboratory of Soil and Water Processes in Watershed, College of Geography and Remote Sensing, Hohai University, Nanjing, P.R. China
Temperature sensitivities (Q10) of nitric oxide (NO) and nitrous oxide (N2O) emissions are the core parameters to project future trajectories of soil nitrogen (N) cycling and climate feedback. However, spatial variations in Q10 and their underlying microbial processes are unknown, hindering accurate projection. We sampled 21 upland soils across a 4000-km transect in China and conducted incubations at 5 to 40°C with 15N tracer to quantify Q10 of NO and N2O emissions, alongside process-specific emissions from nitrification, denitrification and co-denitrification. Optimal temperatures (Topt) for these processes exceeded 30°C and increased with mean annual site temperature. Q10 ranged widely from 1.3 to 5.7 (averaged 3.3) and 1.0 to 5.9 (averaged 3.5) for NO and N2O emissions, respectively, showing higher values observed in lower mid-latitudes and high-pH croplands. The Q10 values were governed by shifts in the ratios between nitrifier and denitrifier functional genes, which are in turn regulated by edaphic and climatic factors. Our observed Q10 values are significantly higher than the default of 2 set in Earth System Models (ESMs). Integrating the experiment-derived Q10 values into model projections reveals that current ESMs underestimate future NO and N2O emissions by 17.5–26.6% across the Shared Socioeconomic Pathways (SSP3-7.0 and SSP5-8.5) by 2100. This suggests a substantial underestimation of future gaseous N losses from global croplands under warming.
How to cite: Ba, W., Yu, H., Yu, L., Dörsch, P., Nie, M., Han, P., Hobbie, E., Fang, Y., and Zhou, F.: Substantial underestimation of soil nitrogen gaseous losses from global croplands under warming, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8694, https://doi.org/10.5194/egusphere-egu26-8694, 2026.
