As a consequence of the recognition that colluvial soil stores large amounts of soil organic carbon (SOC), the SOC cycle in colluvial soils has received increasing attention. The aim of this thesis was to evaluate and understand the SOC dynamics and controlling factors in colluvial soils in the context of climate change. This was done for two specific colluvial environments: eroded and terraced agricultural systems. For the eroded colluvial soils, soil deposition rate is identified as the most important independent control on SOC stability and this is independent of climate zone. In addition, the rate of deposition also indirectly affects SOC stability by changing the average weathering status and mineral matrix of colluvial (sub)soil settings which affects mineral–dependent SOC physico-chemical protection mechanisms. The remaining part of this thesis focused on the colluvial SOC dynamics in terraced systems. Firstly, we demonstrate that the soil infrared spectroscopy, combined with the compositional data analysis enables efficient and reliable ‘large–scale’ assessment of terracing soil properties relevant to SOC biogeochemical cycles. Furthermore, we confirm that the terraced landforms store more SOC than non-terracing landforms, mainly due to the preservation of SOC by topsoil burial in colluvial settings. Finally, we demonstrate that the terrace soil age is a key factor in controlling soil heterotrophic respiration of subsoils (e.g., burial layers), through driving the mineral weathering and thus determining the availability of reactive mineral surfaces that stabilize SOC. In addition, the terrace soil age is also a fundamental regulator of SOC temperature sensitivity (Q10) to decomposition by governing the temporal evolution of SOC fractions and soil C:N ratio (C quality). This thesis demonstrates the need to consider the specific mechanisms of SOC stabilization and temperature sensitivity to fully understand future C cycling of colluvial soils in the light of climate, land use and land management change