Formulating Cost Efficient, Low Environmental Load Forestry Operations: Logging Residue Transportation and Infrastructure Provision for Broad-leaved Tree Harvesting

摘要

We propose a simple formulation to determine achieved improvements on investment level as a function of work in a commercial forestry operation. Two trial approaches are presented. The first attempts to formulate the relationship between unit costs and environmental loads such as CO_2 emissions and energy consumption as a function of logging residue transportation distance. In general, transportation efficiency increases with scale: modal transfer from small to large scale transportation can be achieved through enabling infrastructure investment, such as the provision of intermediate landings. In our case study, four transport capacities were considered (i.e. trucks with 0.35, 2, 4 and 10 t capacities), with loading by a grapple loader sited at an intermediate landing. The optimum formulation was then applied to the second trial, which focused on infrastructure development for broad-leaved species harvesting, namely the construction of forest road networks. Three modes of extraction were considered, grappling, winching and a simple cable system, with two levels of infrastructure provision: 2.5 m wide spur road networks using mini-forwarders and 3.0 m wide forest road networks using 0.45 m3 bucket class excavator machines. Application of the derived formulation indicated thresholds for when each of the modes or systems was most appropriate.