Journal of Resources and Ecology ›› 2019, Vol. 10 ›› Issue (2): 155-162.DOI: 10.5814/j.issn.1674-764X.2019.02.006

• Grassland Ecosystem • Previous Articles     Next Articles

Soil Respiration Dynamics and Influencing Factors in Typical Steppe of Inner Mongolia under Long-term Nitrogen Addition

DU Wei1, WU Shanmei1, NIE Cheng1, LI Yue1, SHAO Rui2, LIU Yinghui1,*(), SUN Nan3,*()   

  1. 1. State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
    2. Department of Geography, Ghent University, Ghent 9000, Belgium
    3. Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/National Engineering Laboratory for Improving Quality of Arable Land, Beijing 100081, China
  • Received:2018-10-17 Accepted:2018-12-29 Online:2019-03-30 Published:2019-03-30
  • Contact: LIU Yinghui,SUN Nan
  • Supported by:
    National Key Research and Development Program of China (2017YFC0503805);National Natural Science Foundation of China (31770519).

Abstract:

We investigated soil respiration (Rs) dynamics and influencing factors under different nitrogen (N) addition levels (0, 2, 4, 8, 16, 32 g m-2 yr-1) on typical grassland plots in Inner Mongolia. We measured soil respiration, temperature, moisture and nutrients. We found that N addition did not change dynamic characteristics of Rs; daily and seasonal dynamics followed a single peak curve. N addition reduced Rs during the growing season. Rs under N2, N4, N8, N16 and N32 treatments decreased by 24.00%, 21.93%, 23.49%, 30.78% and 28.20% in the growing season, respectively, compared to the N0 treatment. However, Rs in the non-growing season was not different across treatments. Rs was significantly positively correlated with soil temperature and moisture and these two factors accounted for 72%-97% and 74%-82% of variation in Rs, respectively. The soil respiration temperature sensitivity (Q10) was between 2.27 and 4.16 and N addition reduced Q10 except in the N8 treatment.

Key words: soil respiration, nitrogen addition, soil temperature and moisture, soil nutrients, typical grassland