Tropical deforestation and land conversion has been an environmental challenge over time and this is likely to have wide-reaching consequences for soil CO₂ efflux. Such soil-carbon dynamic disturbances are critical in light of climate change, as tropical forests store almost 30% of global forest carbon. Soil CO₂ efflux and environmental factors were determined in four different forest ecosystems of primary Dipterocarp forest, a 50-year-old recovering Dipterocarp forest, and a 5-year-old rubber and oil palm plantation using an automated soil CO₂ chamber technique (Li-Cor 8100) with an in-built infrared gas analyzer. The forest sections are located within 1,800 m of each other while the plantation is 1,500 m away in the tropical lowland forest of Pasoh, Peninsular Malaysia. The aim was to determine the influence of environmental factors influencing soil CO₂ efflux in relation to different forest ages and stand densities as a result of forest disturbance. Multiple regression analysis has been conducted on the relationship between soil CO₂ and environmental factors. Soil CO₂ efflux rate was found to range from 1.47-13.22 μmolCO₂ m^-2·s^-1 (5.37 μmolCO₂ m^-2·s^-1), 1.18-10 μmolCO₂ m^-2·s^-1 (5.107 μmolCO₂ m^-2·s^-1), 0.88-12.07 μmolCO₂ m^-2·s^-1 (3.260 μmolCO₂ m^-2·s^-1), and 2.33-7.89 μmolCO₂ m^-2·s^-1 (4.678 μmolCO₂ m^-2·s^-1) in the 50-year-old recovering forest, primary forest, oil palm plantation, and rubber plantation, respectively. Likewise, the highest forest biomass occurred in the primary forest and was followed by the 50-year-old recovering forest, rubber and oil palm plantation. Although the mean soil CO₂ efflux rate did not differ significantly, differences were evident in the environmental factors such as soil temperature and moisture occurring at a range of 23 to 32°C and 15 to 35.56%, respectively, to influence soil CO₂ efflux. The highest CO₂ efflux rate was recorded in the 50-year-old recovering forest and followed by the primary forest, and rubber and oil palm plantation. The finding revealed a significant and strong correlation between soil CO₂ efflux and soil temperature, moisture, and forest carbon input. Furthermore, the spatial variation in soil CO₂ efflux was attributed to total above-ground biomass, below ground biomass, and forest carbon stock. We can conclude that the spatial variation in Soil CO₂ efflux across the four different forest ecosystems is as a result of forest disturbance and land conversion triggering changes in environmental factors as well as forest carbon, thereby increasing microbial activity to emit soil CO₂.