Comparative Time Study of Conventional Cut-to-Length and Integrated Harvesting Method - A Case Study

Abstract

This study compares two harvesting methods i.e., conventional cut-to-length (CTL) followed by harvesting residuall extraction for energy and integrated harvesting method combining CTL with harvesting residual pre-pilling by harvester followed by extraction of both timber and logging residual for energy. The study was carried out in spruce stands (Picea abies) in South Moravia (Czech Republic) at the PozoA™ice and KuniAky locations. Two methods conducted by harvesters and forwarders were compared. The first case was a conventional CTL method when trees are felled, delimbed, and cross-cut by harvester. The resulting logs are pre-pilled and then transported by forwarder. In this case, the harvesting residual remains in the stand. It was not about using harvesting residual as brash mat on the strip roads, but extracting them independently of harvesting later for energy. In the second case, the resulting harvesting residual were piled up by harvester, later to be extracted by forwarder. Such extracted harvesting residual are stored at the roadside for seasoning and future comminution. The aim was to obtain input data for internal analysis of a private entity contracting in logging operation. The client demanded measuring the increase in time needed to produce one timber unit with simultaneous harvesting residual preparation. In our case integrated harvesting was 33% more time demanding of harvesters and 16% less time demanding of forwarders during harvesting residual extraction, which might result in about 8% higher total operational time of complete operation.