Chin J Plant Ecol ›› 2024, Vol. 48 ›› Issue (4): 0-0.DOI: 10.17521/cjpe.2022.0346

   

Temperature sensibility of soil net nitrogen mineralization rates in different types of grassland

Wang Ge1,Hu Shuya2,Yang LI3,Chen Xiaopeng4,Hong-Yu Li5,Kuan-Hu DONG5,Nianpeng He6,Chang-Hui Wang6,6   

  1. 1. College of grassland science, Shanxi Agricultural University
    2. Institute of botany,the Chinese academy of sciences
    3. Institute of Botany
    4. Pratacultural College of Shanxi Agricultural University
    5. Shanxi Agricultural University
    6.
  • Received:2022-08-25 Revised:2023-02-15 Online:2024-04-20 Published:2024-05-11
  • Contact: Chang-Hui Wang

Abstract: Aims Soil available nitrogen (N), generated from a series of soil mineralization processes, is a major limiting factor of terrestrial ecosystem productivity. Soil N availability depends on soil microorganisms, vegetation types and soil physical and chemical properties. Soil microorganisms are very sensitive to environmental changes, especially the temperature changes are closely related with microbial growth and reproduction. Therefore, it is important to understand the temperature sensitivity (Q10) of microbial regulation of nitrogen mineralization in a large spatial scale to predict the impacts of global climate changes on terrestrial ecosystem productivity. Methods We selected three types of grasslands (namely meadow steppe, typical steppe, and desert steppe) respectively in Nei Mongol Plateau, Loess Plateau, and Qingzang Plateau, measured soil N mineralization rates at different temperatures in the laboratory, and calculated Q10 with mineralization results at different temperatures. Soil microbial indexes and soil physical and chemical properties were also analyzed. Important findings The highest Q10 of soil net N mineralization was found in Loess Plateau among three grassland types, compared with grassland types of other two plateaus. The Q10 values of soil net N mineralization in meadow steppe and typical steppe on the Loess Plateau and Nei Mongol Plateau were significantly higher than that in desert steppe while on the Qingzang Plateau, the values in alpine meadow were significantly lower than that in alpine typical steppe and alpine desert steppe. (3) The soil microbial biomass carbon was significantly correlated with temperature sensitivity of soil net nitrogen mineralization rate. (4) The spatial pattern of Q10 is jointly regulated by microorganisms, soil texture and substrate. The results of this study provide important data for the study of the response of grassland soil nitrogen cycle to global change in northern China, which has important scientific value for the calibration of N cycle models in terrestrial ecosystems in the future.

Key words: ammonia-oxidizing microorganisms, microbial biomass carbon and nitrogen, net nitrogen mineralization rate, temperature sensibility (Q10)