Forest soils have a steep carbon gradient from the forest floor to the mineral soil, indicating that carbon is prevented from entry into the soil. Wild boar are effective in mixing the soil when searching for food. In a 6–year field study, we found no significant changes in soil organic carbon stocks in the wild boar treatment plots. However, around 50 % of forest floor carbon was transferred with mixing into mineral soil carbon and increased the stabilised fraction of soil organic carbon.