Chin J Plant Ecol ›› 2023, Vol. 47 ›› Issue (11): 1483-1492.DOI: 10.17521/cjpe.2023.0011

• Research Articles • Previous Articles     Next Articles

Nonlinear response of greenhouse gases emission to nitrogen addition in a meadow steppe

GE Ping1,2, LI Ang2, WANG Yin-Liu2, JIANG Liang-Chao2, NIU Guo-Xiang2, HASI Muqi’er2, WANG Yan-Bing2, XUE Jian-Guo2, ZHAO Wei1,*(), HUANG Jian-Hui2,*()   

  1. 1College of Agriculture, Henan University of Science and Technology, Luoyang, Henan 471023, China
    2State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
  • Received:2023-01-12 Accepted:2023-05-12 Online:2023-11-20 Published:2023-12-22
  • Contact: (Zhao W,; Huang JH,
  • Supported by:
    National Natural Science Foundation of China(32071562)


Aims How nitrogen (N) addition impacts the emission of greenhouse gases (GHGs) is now becoming a hot issue in the study of global change. We aim to delineate the effects of N addition on the emission of major greenhouse gases (CO2, CH4and N2O).

Methods In order to achieve this goal, the flux of the three major GHGs was measured using static chamber gas chromatography during the growing seasons (May through September) of 2020 and 2021 in a meadow steppe of Hulun Buir in Nei Mongol. The experiment was conducted by applying NH4NO3 to simulate the atmospheric N deposition, which involved six N addition levels (i.e., 0, 2, 5, 10, 20, 50 g·m-2·a-1) and two grassland utilization levels (i.e., mown and unmown).

Important findings The results showed that the response of the three GHGs to N addition showed clear nonlinear patterns, but there was a remarkable difference in the patterns among the three GHGs. The emission of CO2 was increased with increasing N addition but saturated at around 10 g·m-2·a-1. The uptake of CH4 was promoted with increasing N addition when N addition was low (0-5 g·m-2·a-1), but this promotion effect was diminished with further increase in N addition (5-10 g·m-2·a-1), and the uptake of CH4 was inhibited when N addition reached 50 g·m-2·a-1. The emission of N2O increased significantly with the increase of N addition rates, but the response patterns and amplitude showed remarkable difference between the two years. With the data in the two years pooled, the CO2 flux had a significant positive correlation with precipitation and nitrate nitrogen (NO- 3-N) content, and a significant negative correlation with pH; CH4 absorption flux was significantly positively correlated with precipitation and ammonium nitrogen (NH+ 4-N) content, while negatively correlated with pH; N2O flux was significantly positively correlated with soil temperature and NH+ 4-N content, while significantly negatively correlated with NO- 3-N content. Our findings demonstrated that the response of the three GHGs to increasing atmospheric N deposition was largely nonlinear, and the response patterns were remarkably different among the three GHGs. These findings may be of great importance for controlling N fertilizer use, selecting appropriate grassland use, and evaluating grassland ecosystem warming potential under increasing atmospheric N deposition.

Key words: meadow steppe, nitrogen addition, mowing, greenhouse gas emission, Hulun Buir, nonlinear response, nitrate nitrogen, ammonium nitrogen