Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (5): 516-527.DOI: 10.17521/cjpe.2020.0169

• Research Articles • Previous Articles     Next Articles

Effect of soil organic matter chemical compositions on soil protease and urease activity in alpine grassland soils in Northern Xizang, China

MA Shu-Qin1, WANG Zi-Wei2,3, CHEN You-Chao4, LU Xu-Yang2,*()   

  1. 1College of Tourism, Henan Normal University, Xinxiang, Henan 453007, China
    2Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
    3University of Chinese Academy of Science, Beijing 100049, China
    4Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China
  • Received:2020-05-25 Accepted:2020-07-17 Online:2021-05-20 Published:2020-08-07
  • Contact: LU Xu-Yang
  • Supported by:
    the National Natural Science Foundation of China(41671262);the National Natural Science Foundation of China(41877338)

Abstract:

Aims Soil enzymes play an important role in the process of soil nutrient transformation. The main purpose of this study is to explore the chemical composition of soil organic matter and its effect on soil protease and urease activity in alpine grasslands in Northern Xizang, China.
Methods The pyrolysis Gas Chromatograph/Mass Spectrometer (Py-GC/MS) was used to obtain the chemical compositions of soil organic matter, and to analyze the relationships between soil chemical compositions and soil enzyme activity in five alpine grasslands, including alpine meadow, alpine steppe, alpine meadow steppe, alpine desert steppe and alpine desert ecosystems.
Important findings The results showed that the enzyme activities among five alpine grassland soils (0-15 cm) were different. Soil urease activity was significantly higher than soil protease activity in the alpine desert steppe, while the difference between the urease and protease activities was not significant in other types of alpine grasslands. Soil protease activity was significantly different among five alpine grassland types, but soil urease activity was not. The correlation analysis showed that soil protease activity was closely related to the relative abundance of alkanes, alkenes and aromatics in soil organic matter and the ratio of furfural to pyrrole. However, the correlation relationships between urease activity and soil organic matter chemical compositions were not significant. The results indicated that alpine grassland type and soil organic matter chemistry were the key factors affecting soil protease activity, but their effects on soil urease activity was non-significant, which calls for further study on the influencing factors on soil urease activity.

Key words: alpine meadow, alpine steppe, soil organic matter chemical composition, enzyme activity, Pyrolysis Gas Chromatograph/Mass Spectrometer (Py-GC/MS)