Soil carbon projections in a Mediterranean area using RothC model

Soil organic carbon (SOC) plays a vital role in ecosystem function determining soil fertility, water holding capacity and susceptibility to land degradation. In addition, SOC is related to atmospheric CO2 levels with soils having the potential for C release or sequestration, depending on land use, land management, and climate. Estimates of soil organic carbon stocks and changes under different climate scenario and land use systems can help determine vulnerability to land degradation. In this work an assessment of changes in soil organic carbon for Sardinia, the second largest island of the Mediterranean Basin, is presented. Soil carbon dynamics were estimated for the whole island using the Rothamsted Carbon model and the A1b emission scenario provided by the Euro-Mediterranean Centre for Climate Change (CMCC). The RothC model was previously calibrated for several land use typologies. Almost 170 soil analysis data, coming from several land use typologies, were used for calibration and results comparison. After the calibration, a good agreement between soil C estimated from the model with the current climate and real data was found. Preliminary results show a general reduction in the soil C content with the A1b scenario projection. Results also show that not only climate change, but also changes in land use, and in the net primary production, should be evaluated in soil C stock predictions.