Abstract: By using static chamber and gas chromatography methods, this paper studied the effects of clear cutting and selective cutting on the CO₂, CH₄, and N₂O emissions from Larix gmelini-Sphagnum swamp in Lesser Xing’an Mountains. Dramatic changes in the seasonal dynamics of CH₄ and N₂O emissions were detected in different treatment sites. Control site absorbed CH₄ in summer and emitted CH₄ in autumn, and absorbed N₂O in both summer and autumn; selective cutting site emitted CH₄ and N₂O mainly in summer; and clear cutting site emitted CH₄ in summer and autumn, and absorbed N₂O in summer but emitted it in autumn. Cutting pattern had less effects on the seasonal dynamics of CO₂ emission. Both on the clear cutting site and on the selective cutting site, the CO₂ emission was in order of summer>spring>autumn. Forest cutting altered the source and sink functions of the sites. Control site functioned as a source of CO₂ and a weak sink of CH₄ or N₂O, while forest cutting sites had a decrease of CO₂ emission by 25%, and became a weak source of N₂O and a weak or strong source of CH₄. Compared with that of control site, the Global Warming Potential (GWP) of selective cutting site and clear cutting site was reduced by 24.5% and increased by 3.2%, respectively.

Key words: Lesser Xing’an Mountains, Larix gmelini-Sphagnum swamp, greenhouse gas, emission, cutting, water ecological carrying capacity, water ecological footprint, ecosystemservicebased ecological footprint (ESEF), Taihu Lake Basin.