Afforestation is a good mitigation activity to climate change because it causes sequestration of CO2
from the atmosphere and stores it as the living biomass and the dead
organic matter. However, the response of soil organic carbon (SOC) to
afforestation in deep soil layers is still poorly understood. This article
surveys 56 previously published studies for changes in deep SOC after
afforestation of both croplands and grasslands. It concludes that converting cropland to forestry has a highly positive impact on SOC (1.3-1.6 times greater), converting grassland to forestry much less so.