Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài: Productivity and cost of manual felling with a chainsaw in Caspian forests. | JOURNAL OF FOREST SCIENCE 55 2009 2 96-100 Productivity and cost of manual felling with a chainsaw in Caspian forests F. K. Behjou1 B. Majnounian1 J. Dvorak2 M. Namiranian1 a. Saeed1 J. Feghhi1 1Faculty of Natural Resources Teheran University Teheran Iran Faculty of Forestry and Wood Sciences Czech University of Life Sciences in Prague Prague Czech Republic ABSTRACT A field production study was conducted for a manual harvesting system using a chainsaw in a Caspian hardwood forest site. A selective cut was performed on a 42-hectare tract with an average slope of 30 percent. Felling time per tree was most affected by diameter at breast height and by the distance among harvested trees. The gross and net production rate was m3 and m3 per hour one person respectively. The unit cost considering the gross and net production rate was USD m3 and USD m3 respectively. The significant variables included diameter at breast height D and distance among harvested trees L for the time expenditure model. This regression function is statistically significant at a . Keywords chainsaw working efficiency unit cost felling The area of natural forests in Iran is approximately million hectares equal to of the total area of Iran. Approximately million ha are commercial forests called Caspian forests Hyrcanian or Northern forests Limaei Lohmander 2007 . The commercial forests are located in the northern part of Iran between north of the Alborz Mountains and south of the Caspian Sea. These forests are unevenaged structures of varying species composition such as beech Fagus orientalis hornbeam Carpinus sp. maple Acer sp. oak Quercus sp. Limaei Loh-mander 2007 . In Iran industrial logging is carried only in the Caspian forests. High-quality hardwood sawn timber is being harvested in these forests. Information on the productivity cost and application of harvesting machines is a key component in the evaluation of management plans for the rehabilitation and .
