An analysis of whole tree harvesting in North Italian cable logging operations

Five cable logging operations were selected in the Como Lake area - in Northern Italy - with the purpose of exploring the effects of introducing whole tree harvesting as a replacement of traditional full-length stem harvesting. For each operation, two adjacent and parallel lines were set up, with the same length and removal intensity. On one line harvesting proceeded as usual and trees were motor-manually felled and delimbed, yarded as full length stems, and finally crosscut and stacked at the landing using a chainsaw and an excavator. On the other line, trees were motor-manually felled, yarded whole and mechanically processed at the landing. All work time was recorded, separately for different activities. Output was also measured and allocated to different assortments. All fuel consumption was recorded, which allowed estimating financial and energy cost. After harvesting, a complete assessment of the amount of residues left in the stand was also conducted, using a standardized sampling method. Time consumption per unit product was 20 to 40% lower for the whole tree system, compared with the traditional full length stem system. Fuel consumption per unit product was also 20 to 30% lower for the whole tree system. The whole tree system did not result in the complete removal of all residue biomass. In fact, whole tree harvesting resulted in a reduction of the residue load between 30% and 65%. Even after whole tree harvesting, at least one third of the logging residues was left in the forest.