| Summary: | Using a static chamber-gas chromatography method, we investigate the characteristics of soil CO<sub>2</sub>, CH<sub>4</sub>, and N<sub>2</sub>O fluxes and their relationships with environmental factors during the growing season in four typical <i>Larix gmelinii</i> forests (moss–<i>Larix gmelinii</i> forest, <i>Ledum palustre</i>–<i>Larix gmelinii</i> forest, herbage–<i>Larix gmelinii</i> forest, and <i>Rhododendron dauricum</i>–<i>Larix gmelinii</i> forest) in the Greater Khingan Mountains. Our results show that all four forest types are sources of CO<sub>2</sub> emissions, with similar average emission fluxes (146.71 mg·m<sup>−2</sup> h<sup>−1</sup>–211.81 mg·m<sup>−2</sup> h<sup>−1</sup>) and no significant differences. The soil in the moss–<i>Larix gmelinii</i> forest emitted CH<sub>4</sub> (43.78 μg·m<sup>−2</sup> h<sup>−1</sup>), while all other forest types acted as CH<sub>4</sub> sinks (−56.02 μg·m<sup>−2</sup> h<sup>−1</sup>–−28.07 μg·m<sup>−2</sup> h<sup>−1</sup>). Although all forest types showed N<sub>2</sub>O uptake at the beginning of the growing season, the N<sub>2</sub>O fluxes (4.03 μg·m<sup>−2</sup> h<sup>−1</sup>–5.74 μg·m<sup>−2</sup> h<sup>−1</sup>) did not differ significantly among the four forest types for the entire growing season, and all acted as sources of N<sub>2</sub>O emissions. The fluxes of CO<sub>2</sub>, CH<sub>4</sub>, and N<sub>2</sub>O were significantly correlated with soil temperature and soil pH for all four forest types. Multiple regression analysis shows that considering the interactive effects of soil temperature and moisture could better explain the changes in greenhouse gas emissions among different forest types. The average <i>Q</i><sub>10</sub> value (8.81) of the moss–<i>Larix gmelinii</i> forest is significantly higher than that of the other three forest types (3.16–3.54) (<i>p</i> < 0.05), indicating that the soil respiration in this forest type is more sensitive to temperature changes.
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