Modelling the productivity and economic feasibility for bioenergy production in a Mediterranean oak coppice

Abstract

The possibility of further exploiting the national bioenergy supply chain in Italy is hindered by a lack of economically sustainable mechanization. Large enterprises can rely on brand-new and advanced machinery to improve productivity and maximize revenue. On the other hand, small enterprises often resort to custom-built machinery to accomplish the same tasks. The performance of an excavator equipped with forest shears was used to model its productivity and economic feasibility in an oak coppice in central Italy. The oak coppice harvesting operations required 29, 19, 22, 20 and 10% of total time respectively for clearing, moving, felling, bunching and delay. The linear model highlighted a strong influence of diameter at breast height (DBH) on the total productivity, with a p value lower than 0.001 and an adjusted R2 of 0.64. Felling and bunching operation costs ranged from 10.89 to 31.45 EUR t-1, the latter one corresponding to a DBH value of 9 cm. Hence, our findings indicate the minimum stand requirements necessary to ensure the economic sustainability of excavator-based harvesting in these specific conditions.