1 دانشجوی کارشناسی ارشد جنگلداری، دانشکده منابع طبیعی، دانشگاه تربیت مدرس، ایران
2 استادیار دانشکده منابع طبیعی، دانشگاه تربیت مدرس، ایران
3 استادیار دانشکده منابع طبیعی، دانشگاه تهران، ایران
عنوان مقاله [English]
Having accurate information regarding to performance of skidding operations is essential to improve the economic status of a project for forest managers and contractors. The current study assessed the performance of farm tractor and mule logging systems to determine optimum combination of them. For this purpose continuous time study was used. The production model was developed using multiple regression model. Independent effective variables on farm tractor productivity were identified as skid trail slope and skidding distance and for animal system productivity the effect of skidding distance and interaction of distance and slope were significant. Productivity rate of farm tractor and animal skidding were 8.40 and 1.27 m3/hr, respectively. Costs of farm tractor and mule system were estimated 15,957 and 78,434 Rials per cubic meter, respectively. The results indicated that to reach best combination of two systems, timber must be transported as far as possible on skid trails by tractor, in this case total skidding cost will be reduced by 35%. Animal skidding system still must be limited in area where there is impossible to construct skid trail.