Soil CO2 efflux varies significantly in time and space in terrestrial ecosystems, obtaining a detailed understanding of what controls the dynamics of soil respiration (SR) can improve the estimation accuracy of forest
carbon budgets. We examined the effects of forest conversion (from primary forest to both secondary forest and
coniferous plantations) on the temporal dynamics of SR and its components (heterotrophic = RH, and
autotrophic = RA), at both seasonal and inter-annual time scales within four adjacent forest stands in northeastern China. Trenching method was used to partition RH and RA. The results showed that RH was the primary
contributor to the overall magnitude and variability of SR, which showed similar seasonal and inter-annual
variation, while RA displayed higher temporal variation compared to SR and RH. Generally, the between-year
seasonal variation of SR and RH varied significantly in both secondary forest and plantations. The secondary
forest exhibited a relatively higher seasonal change in RA compared to that in primary forest and coniferous
plantations, while there was no significant disparity in the seasonal and inter-annual variation of SR and RH
among forest stands. Soil temperature was the primary factor driving the temporal dynamics of RH and accounted for 63–91% and 22–64% of seasonal and inter-annual variations, respectively. However, RA was less
controlled by soil temperature. This study implies that forest conversion magnifies the responses of RH to the
minor variations in the between-year seasonal patterns of soil temperature and increases the seasonal variability
of RA.