Afforestation and reforestation: the Sicilian case study

In some regions of the world such as the Northern Hemisphere, theabandonment of agricultural land is one of the most widespread forms of land usechange. In general, abandonment is followed by colonization by herbaceous andwoody plants. Since the 1950s, wide areas of Southern Italy have been afforestedfor soil conservation improvement. In order to quantify the effects of agriculturalabandonment and artificial afforestation on soil organic carbon (SOC), a dataset of48 Sicilian sites has been analyzed. Because of their high environmental variability,these sites can be considered as representative of Southern Italy and in generalof the Mediterranean basin. Soil samples were taken throughout all bioclimates indifferent successional stages (cultivated areas: orchards, cereal crops, herb-dominatedplant communities, grasslands dominated by perennial grasses, garriguesand low shrublands, maquis, natural forests and in nearby artificially afforestedsites (Pine plantations)). The study confirmed that SOC accumulation after agriculturalabandonment depends on bioclimate: the highest SOC accumulation wasrecorded in the meso-mediterranean bioclimate, intermediate in the thermo-mediterranean,and the lowest in the supra-mediterranean bioclimate. Data showed thatfor C sequestration in the soil, artificial afforestation is not convenient in comparisonto natural afforestation by spontaneous secondary succession processes.