Conifer afforestations in Italy: an opportunity for wood energy and forest restoration

Abstract

The restoration of conifer plantations into stands with a more complex structure and composition is a current challenge for the Italian silviculture and an opportunity to provide wood energy. A silvicultural system aiming to the natural regeneration by means of canopy gaps (gap-based approach) has been applied in an experimental site in the Calabrian pine (Pinus nigra Arn. ssp. laricio Poiret var. Calabrica Delamare) stands in the Calabrian Apennine initiated in 2003: small (380 m²), medium (855 m²) and  large gaps (1520 m²) were compared.

The main results after 7 years show that the most appropriate gap sizes for regeneration of Calabrian pine (shade-intolerant species) are those of 1500 m2 with a d/h of 2.0. While for late-successional species (silver fir and beech) gaps of 380 m2 with a d/h of 1.0 or slightly larger are recommended. This allows the forest manager to choose whether to maintain the pine or initiate a restoration action with native forest vegetation. The interval between cuttings is 7 years. Whereas any intervention removes the 30% of the forest, the cycle is complete in about 20 years. In this case (stands normally thinned) at the time of the first cutting from 15 up to 70 m3 per gap, or 140 m3 per hectare can be obtained. This gap-based approach is a sustainable silvicultural treatment because of low environmental and aesthetic impact and also meets objectives for timber production