Carbon storage in soils

Key points• Carbon occurs in different forms in soils: in living organisms, dead organic matter with particulate organic matter, organicmolecules, and as inorganic carbon• Soil carbon stock and soil carbon storage are different concepts: a carbon stock is quantified at a given date while its storageis quantified over a period of time• The carbon stock distribution across the planet is heterogeneous, and complex biotic and abiotic processes underlie itsdynamics• For a given soil and climate, the largest stocks are found in forests and grasslands. In comparison, cultivated soils are carbondepleted• Land-use changes and agricultural practices have a major impact on soil carbon stocks: they may have negative, positive ordiverse effects on carbon storage, depending on climate and soil conditions• Soil carbon storage provides socioeconomic benefits as targeted by five Sustainable Development Goal