Time Consumption of Timber Harvesting and Forwarding from Pine Thinning Stands in Terrain with Linear Unevenness

Terrain roughness and local unevenness are included in the classifications of technological accessibility of stands, which are the starting point for functional classifications. The aim of research was to determine the impact exerted on the time consumption of timber harvesting and forwarding by linear terrain unevenness remaining after soil preparation for planting in the form of trenches and ridges with a depth ranging from 0.2 m to 0.6 m. The research was conducted in pine stands where early thinning was being carried out applying harvesters, forwarders and agricultural tractors with forestry trailers. The share of main work time and complementary work time for harvesters amounted to approx. 50%, of which delimbing and bucking accounted for 35%, and tree felling for 15%. The times of forwarding and unloaded journeys amounted to 28% for forwarders and were shorter by approx. 17% as compared to forest trailers. The share of loading and unloading times amounted to approx. 50%. Higher moving time was noted in the case of harvesting in stands with deeper linear unevenness of the terrain and when machines ran on skid trails perpendicular to unevenness. In the Eco Wood land accessibility classification applied in forest practice, we propose the use of a new factor, linear unevenness of terrain.