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FOREST RESOURCES WANAGEMENT ›› 2023›› Issue (2): 88-95.doi: 10.13466/j.cnki.lyzygl.2023.02.012

• Scientific Research • Previous Articles     Next Articles

Diurnal Variation of Soil N2O Emission Fluxes and Its Influencing Factors in Pinus tabulaeformis Plantation

LI Xiaoyang1(), MA Xiuzhi1(), YANG Yupei1, LI Changsheng2   

  1. 1. College of Forestry,Inner Mongolia Agricultural University,Hohhot 010019,China
    2. Hohhot Meteorological Bureau,Hohhot 010051,China
  • Received:2023-02-01 Revised:2023-04-23 Online:2023-04-28 Published:2023-06-26

Abstract:

In the context of global warming,the diurnal variation of annual soil N2O emission flux in Pinus tabulaeformis plantation was revealed,and the optimal daily sampling period was determined based on the daily dynamic data of N2O emission flux observation,which provided basic data for accurate assessment of regional soil N2O flux.The N2O emission fluxes in the growing season and freezing-thawing period of Pinus tabulaeformis plantation in 2020—2021 were measured by static box gas chromatography (GC).The results showed as follows:1) During the growing season (June-September 2020),the average N2O emission flux of the observation days all appeared during 15:00—17:00 of the same day;During freeze-thaw period (November 2020 to March next year),the observed values from 8:00 to 12:00 on the observation day were close to the daily mean value of N2O flux.2) In 2021,the average N2O emission flux of observation days appeared in the period of 7:00—9:00 on July days and 15:00—17:00from June days to September days.According to the results,the best sampling time of N2O in Pinus tabulaeformis plantation in Daqing Mountain was 9:00 AM or 15:00 PM in the growing season and 8:00 am in the freezing-thawing period.The obtained flux value could represent the average N2O flux of the day after correction.According to the analysis results,temperature in the growing season and the freeze-thaw period and the N2O emission flux effect value,it can be determined that temperature is an important factor for the N2O emission of Pinus tabulaeformis plantation in Daqing Mountain.

Key words: Pinus tabulaeformis plantation, N2O emission flux, soil temperature, diurnal variation, monthly variation

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