Abstract
Forest harvesting is a system and the most expensive part of forest management. The main objective of the harvesting engineer is to minimize harvesting costs and damages. To manage such operations properly, it is necessary to understand the components of the harvesting system. Felling is one of the components of the harvesting system, which is carried out by means of power saw in Iran. Tree felling by power saw was studied in Patom Section (113, 116 and 118 compartments) of Kehyroudkenar Forest Research Station using elemental time study method, and felling model was examined. The results of the study indicated that the DBH is the most effective factor on felling time and consequently the cost of felling. Felling time or cost has a positive linear relation with DBH. The chainsaw working team, including one feller and two workers, fells 7 trees per hour in average with cost of 309,785 Rials per day.