Optimizing productivity on multistage timber harvesting systems. A case of Shume/Mkumbara system, Tanzania

The fact that most plantation forests are on mountainous areas further complicates harvesting operations and the need for a 'compatible' harvesting system to meet the harvesting objectives becomes more important. This study was carried out in Shume/Mkumbara to establish an optimum timber harvesting system. Data collection was classified into two categories; category one was data collection from the harvesting operations with the existing methods/equipments system at Shume/Mkumbara while the second category was data collection from all possible alternative method/equipments that could be employed to accomplish task at this system from SUA Training Forest and West Kilimanjaro plantation forests. Data were analysed by NETWORK 2000 program and LINDO. Results showed that timber harvesting in this system can be systematically be accomplished through four operational stages with a number of sub operations. Analysis for the optimum harvesting system showed that a new system needs to be introduced into the area. When comparing the existing system with a proposed one, it was found that productivity could be improved by 1.97m(3)/h with total production costs lowered by TShs 310 (about 3%). However, felling pertains should be improved as well as ensuring close supervisions and maintenance of the equipments.