Timber extraction with mules: A case study in the Hyrcanian Forest

The Hyrcanian (Caspian) forest in northern Iran has a richness of biological diversity, with endemic and endangered species, and a diverse range of economic and social conditions. With a focus on low impact timber extraction and small scale tree harvesting, the proportion of mule logging has recently increased. The objective of this study is to assess the efficiency of mule logging operations in the Hyrcanian forests through a comprehensive time study, and further to attempt to identify opportunities for improvement. The research was carried out in the Namkhaneh district of the Kheyroud Forest. Four type mule logging crews were selected for this study, carrying either sawlog or pulpwood sized material, in either uphill or downhill directions. Mule extraction time was recorded, and independent variables expected to affect mule hauling productivity were documented. Average turn time for hauling sawlogs uphill and downhill was 8 and 8.6 min respectively. Turn time for hauling of pulpwood uphill and downhill was 8.24 and 8.06 min respectively. Approximately 20% of the total time was delay. Regression models were developed for production-related elements. Productions of lumbers hauling were more than pulpwoods. The average hourly cost of a mule hauling system in this area was $6.44 per productive mule hour. Overall, the results suggest that mule hauling operation in the Hyrcanian Forest can meet economic, silvicultural, environmental, and social objectives.