Substantial nitrous oxide (N2O) emissions from permafrost-affected regions could accelerate climate warming, given that N2O exhibits approximately 300 times greater radiative forcing potential than carbon dioxide. Pronounced differences exist in N2O emissions between freeze and thaw periods (FP and TP), but the mechanisms by which environmental factors regulate the production and emission of N2O during these two periods have not been thoroughly examined. We therefore combined static chamber gas chromatography, in-situ soil temperature (ST) and moisture (SM) monitoring, and 16S rRNA sequencing to investigate seasonal N2O variations in the Qinghai-Tibet Plateau (QTP) alpine meadow ecosystem, and assess the relative contributions of environmental and microbial drivers. Our findings indicate that N2O fluxes (-3.15 to 6.10 mu g m-2 h-1) fluctuated between weak sources and sinks, peaking during FP, particularly at its late stage with initial surface soil thawing. Soil properties affect N2O emissions by regulating denitrification processes and altering microbial community diversity. During the FP, ST fluctuations control N2O release by modifying mineral nutrient availability. During TP, soil texture modulates denitrification-driven N2O production through its effect on SM. Spring N2O pulses likely originate from microbial reactivation in thawed soil. N2O accumulated in frozen soil may gradually release during vertical profile thawing. On the QTP, a warmer and wetter climate scenario may alter N2O emissions by modifying the duration of the FP and TP and phase-specific hydrothermal allocation. This study provides mechanistic insights for predicting climate change impacts on N2O flux in fragile alpine meadow ecosystems.

来源平台：ATMOSPHERIC ENVIRONMENT