Emissions of CO 2 , CH 4 , and N 2 O Fluxes from Forest Soil in Permafrost Region of Daxing’an Mountains, Northeast China

With global warming, the large amount of greenhouse gas emissions released by permafrost degradation is important in the global carbon and nitrogen cycle. To study the feedback effect of greenhouse gases on climate change in permafrost regions, emissions of CO 2 , CH 4 , and N 2 O were continuously measured by using the static chamber-gas chromatograph method, in three forest soil ecosystems ( Larix gmelinii , Pinus sylvestris var. mongolica , and Betula platyphylla ) of the Daxing’an Mountains, northeast China, from May 2016 to April 2018. Their dynamic characteristics, as well as the key environmental affecting factors, were also analyzed. The results showed that the flux variation ranges of CO 2 , CH 4 , and N 2 O were 7.92 ± 1.30~650.93 ± 28.12 mg·m −2 ·h −1 , −57.71 ± 4.65~32.51 ± 13.03 ug·m −2 ·h −1 , and −3.87 ± 1.35~31.1 ± 2.92 ug·m −2 ·h −1 , respectively. The three greenhouse gas fluxes showed significant seasonal variations, and differences in soil CO 2 and CH 4 fluxes between different forest types were significant. The calculation fluxes indicated that the permafrost soil of the Daxing’an Mountains may be a potential source of CO 2 and N 2 O, and a sink of CH 4 . Each greenhouse gas was controlled using different key environmental factors. Based on the analysis of Q 10 values and global warming potential, the obtained results demonstrated that greenhouse gas emissions from forest soil ecosystems in the permafrost region of the Daxing’an Mountains, northeast China, promote the global greenhouse effect.