Variazione degli stock di carbonio in seguito ai processi di abbandono dei coltivi: il caso studio dell'isola di Pantelleria (Tp)

The recent abandonment of marginal agricultural areas in the Mediterranean has caused an increase ofthe surface occupied by pre-forest and forest formations. In order to study the carbon accumulation processeson Pantelleria Island was selected a North-facing area. This area includes 5 stages of succession (sds) thatcompose a chronosequence (from 0 to 30 years) to understand soil C accumulation processes after abandonment.These are abandoned vineyards or caperbushes, not disturbed (grazing, fire) since agricultural abandonment,and they are situated in thermomediterranean belt and on the same parent material and consequentlyconsidered in the same ecological conditions. Samples at 1 cm, 10 cm and 40 cm depth, respectively,were taken for every sds in three different soil relief areas. Litter samples were taken too. Organic carboncontent was determined for every sample. Carbon content increases from a sds to the next one. There is a duplicationof C from sds0 (cultivated field) to sd1 (abandoned since few years) and from sds4 (abandoned since16-30 years) to sds5 (abandoned since > 30 years). It seems that different types of vegetation play a keyrolein soil C dynamics and there are 85 t C ha-1 in the top 40 cm of the soil after 30 years from the abandonmentin the chronosequence and an annual C sequestration rate equal to 3.4 t ha-1. These results show that revegetationoffers good opportunities to sequestrate CO2 from the atmosphere and, therefore, to mitigate thegreenhouse effect as it is requested by international agreements.