Estimation of soil carbon pools in the forests of Khyber Pakhtunkhwa Province,Pakistan

Forest soils have high carbon densities compared to other land-uses.Soil carbon sequestration is important to reduce CO;concentrations in the atmosphere.An effective climate change mitigation strategy involves limiting the emissions of greenhouse gases from soils.Khyber Pakhtunkhwa is the most forested province of Pakistan,hosting about one-third of the country’s 4.5 × 10;ha forest area.Soil organic carbon in the province’s forests was estimated through a field-based study carried out during 2014-17 covering the whole province.Data was collected from 373 sample plots laid out in different forest types using a stratified cluster sampling technique.The total quantity of soil organic carbon was estimated at 59.4 × 10;t with an average of 52.4±5.3 t/ha.About 69% of the total soil carbon is present in temperate forests.Subtropical broad-leaved and subtropical pine forests constitute 11.4% and 8.8% of the soil carbon stock respectively.Similarly,subalpine and oak forests have respective shares of 5.1% and 5.7% in the soil carbon pool.The lowest carbon stock（0.1 %） was found in dry-tropical thorn forests.The highest soil carbon density was found in subalpine forests（69.5±7.2 t/ha） followed by moist temperate forests（68.5±6.7 t/ha） and dry temperate forests（60.7±6.5 t/ha）.Oak forests have carbon density of43.4±7.1 t/ha.Subtropical pine,subtropical bro ad-leaved and dry tropical thorn forests have soil carbon densities of 36.3±3.7,32.8±6.2 and 31.5±3.5 t/ha,respectively.The forests of the Khyber Pakhtunkhwa province have substantial amounts of soil carbon which must be conserved for climate change mitigation and maintenance of sound forest health.