Productivity Linear Regression Models of Tree-Length Harvesting System in Natural Coastal Aleppo Pine (Pinus halepensis L.) Forests in the Chalkidiki Area of Greece

Time studies of harvesting and skidding tree-length logs in Aleppo pine (Pinus halepensis L.) natural coastal forests of Chalkidiki area in northern Greece were carried out to formulate linear regression models and to evaluate productivity. The harvesting system consisted of a feller with chainsaw for felling, delimbing and crosscutting, and a four wheel drive farm tractor, with a 74 kW engine, equipped with a special winch attached to the tractor three point hitch for the extraction of tree length logs. Operational factors such as distance, slope, volume and the time required for harvesting and extracting tree length logs were measured and recorded. The results illustrate that the calibrated linear regression models show strong correlation between the time needed for harvesting operations and the extraction distance from the stump to the forest road.