Greenhouse Gas Emission Fluxes from Hummocky and Hollow in the Peat Bog of Arak Lake Basin in 2020

Abstract

The peat bogs on the Tibetan Plateau are an important source of carbon dioxide (CO2) and methane (CH4) in Chinese atmosphere. In order to study the effects of different micro-topography of peat bogs on CO2 and CH4 emission fluxes, the static box-meteorological chromatography method was used to determine the CO2 and CH4 emission fluxes of hummocky and hollow in the peat bogs in Arak Lake Basin from May to September in 2020. Our results showed that the peaks of CO2 and CH4 emission fluxes from hummocky and hollow all appeared in July, and the lowest values all appeared in May. The maximum CO2 emission fluxes of hummocky and hollow are 440.44 mg•m-2•h-1 and 198.20 mg•m-2•h-1, respectively, and the maximum CH4 emission fluxes are 2.62 mg•m-2•h-1 and 3.21 mg•m-2•h-1, respectively. The average CO2 emission flux during the growing season of hummocky (368.79±54.70 mg•m-2•h-1) was significantly higher than that of hollow (165.96±20.19 mg•m-2•h-1) (n=5, p=0.001), while the average CH4 emission flux of hummocky (1.78±0.27 mg•m-2•h-1) is significantly lower than that of hollow (2.24±0.27 mg•m-2•h-1) (n=5, p=0.007). The CO2 emission flux of hummocky and hollow during the growing season is mainly affected by the 5 cm soil temperature, and the CH4 emission flux is mainly affected by the 5~20 cm soil temperature.