Productivity and Fuel Consumption in Skidding Roundwood on Flat Terrains by a Zetor Farm Tractor in Group Shelterwood Cutting of Mixed Oak Forests

Productivity assessment studies are essential in forest operations, mainly because their results enable operational planning and rate setting, the development of equitable payment systems, environmental performance, improvements brought by technology development, optimization larger forest-based systems. This study examines productive performance fuel consumption farm-tractor based skidding operations implemented flat terrain oak harvesting developing detailed statistics predictive models on performance. Two felling areas were selected to monitor developed at two resolutions an end-to-end assessment. Based 56 observed work cycles, for average values number logs, payload volume, winching distance extraction 4.96, 1.81 m3, 14.43 m, 177.3 respectively, net efficiency productivity rates estimated 0.125 h/m3 8.03 m3/h, respectively. At resolution piece-by-piece winching, time depended only distance. overall logs a distances. The same predictors relevant explaining which accounted 3.72 L/h or 0.46 L/m3, while there was variation induced type operation. Both found be highly sensitive distances, as main factors affecting them. Nevertheless, significant efficiency, productivity, may achieved when dealing with fewer per turn higher volumes piece, since indicated no effects log size, technical limits used winched reached 8.5 tons.