Assessing organic carbon stock at scale profile in forest soils of Calabria (Southern Italy)

Understanding the amount of carbon content stored in forest soils may help to quantifytheir contribution in climate change mitigation.The main objective of the study was assessing soil organic carbon (SOC) stock at profilescale in a forest area of Calabria region and analysing the relationship between SOCstock and soil texture, soil type and landscape position. Twenty-eight soil pedons werecollected in all physiographic units of the study area and were described and classifiedaccording to USDA classification. All mineral horizons were sampled and analysed forSOC, bulk density and soil texture. Moreover, the organic horizon (O) was sampledand SOC concentration was determined. Finally, the SOC stock along the soil profileswas calculated. The results showed that the soils belonged to Inceptisol and Entisolorders and were from shallow to moderately deep. SOC values of O horizon rangedfrom 217.0 g kg-1 to 369.8 g kg-1 with a mean value of 284.9 g kg-1. In the mineral horizons,SOC ranged from 1.0 to 132.2 g kg-1 with a mean value of 39.8 gkg-1. The meanvalue of total SOC stock for all the profiles was 160.9 Mg ha-1. The mean SOC stockwas 4.8 Mg ha-1 for the organic horizons and 156.2 Mg ha-1 for the mineral horizons.Soil texture, soil types and landscape features controlled SOC stock with higher valuesrecorded in flat areas than on steep slopes. SOC stock was typically lower for Entisolsthan Inceptisols and for loamy sand soils than loamy soils.