Soil CO2 Efflux of oil palm and rubber plantation in 6-year-old and 22-year-old chronosequence

SD = 0.17 g CO2 m?2 h?1) had significantly higher soil CO2 efflux than the 6-year-old stand (M = 0.54SD = 0.18 g CO2 m?2 h?1). Soil RH plays a significant role controlling soil CO2 efflux compared with soil temperature, especially at younger stands of tropical oil palm and rubber plantations spatially. Lower Q10 values were found to be caused by higher temperature that had reduced enzymatic and substrates activities for soil respiration. Non-discernible trends of temporal soil CO2 efflux, soil temperature, and RH indicated that other significant factors could be the catalyst, and thus further research is required to explain the relations between soil CO2 efflux and environmental factors. Research findings indicated that older stand age of oil palm and rubber plantations in Malaysia released higher soil CO2 efflux, but with no degrading effects towards the environment