As potential sources of carbon and nitrogen release, arid saline lakes have undergone drastic ecological changes over the past decades due to soil freeze-thaw processes. These changes have inevitably altered the soil carbon and nitrogen release and sequestration. However, the mechanistic processes governing carbon and nitrogen dynamics in response to ecological changes across the biogeomorphic succession of salt lakes remain poorly understood. This study used the static chamber gas chromatography method and partial least squares structural equation modelling to analyse fluctuations in CO2, CH4, and N2O fluxes in surface soil layer along a biogeomorphic succession comprising lake wetland (LW), marsh wetland (MW), salt marsh wetland (SW), and nonwetland (NW) areas. Freeze-thaw cycles considerably increased the soil carbon and nitrogen release in LW and MW. As the biogeomorphic transition progressed to SW and NW, CO2 release decreased by 32.46 % and 66.99 %, CH4 by 90.28 % and 107.31 %, and N2O by 46.24 % and 86.20 %, suggesting a transition toward a carbon sink. The MW acted as the strongest emission source, with annual average emissions of CO2, CH4, and N2O of 1463.895 x 109 mg center dot m- 2 center dot h- 1, 460.935 x 106 mg center dot m- 2 center dot h- 1, and 722.355 x 106 mg center dot m- 2 center dot h- 1, respectively, mainly driven by the synergistic changes in soil temperature (ST) and soil water content (SWC). During the thawing and melting periods, the emission from MW was higher, but it changed to a carbon sink during the freezing period, associated with the suppression of carbon emissions by low temperatures and the physical sequestration of some carbon. Further evidence showed that the synergistic increase of SWC and ST during the melting period enhanced oxygen permeability, activating methane-oxidising bacteria activity, allowing LW and SW to act as methane sinks (-0.142 mg center dot m- 2 center dot h- 1 and - 0.081 mg center dot m- 2 center dot h- 1, respectively). Compared to subtropical monsoon and subfreezing climate zones, CH4 emissions from MW of arid Lake Ebinur responded rapidly to freeze-thaw cycles, with a peak release during the thawing period mainly due to the intense fluctuations in SWC and the combined action of soil content (SC). This study establishes a dual-focused framework that elucidates seasonal dynamics of carbon and nitrogen release in arid regions while providing scalable solutions for global GHG modelling.