On-site performance tests of a new forest biomass harvesting system termed “Integrated Wood Logging System” were conducted in order to improve logging efficiency and cost-effectiveness. In the integrated harvesting system, the wood logs are loaded and transported without separating butt logs from stem butts during the log bucking process. The loading efficiency, operation speed, productivity, and harvesting costs of this system were evaluated. Two types of forest hauling vehicles and two types of trucks were used in combination with the “conventional” or the “integrated” system. The “non-self-loader” system was composed of an excavator with grapple, a forest hauling vehicle, and a truck. The “self-loader” system was composed of a forwarder (with grapple crane) and a grapple truck. Logging costs were calculated considering a distance of 500 m from logging site to the road, transport distance of 50 km, and 200 operating days/year. For the “non-self-loader” system, the total cost reached 1,978 yen/m³ when stem butts and logs were separately transported. However, the total cost decreased to 1,765 yen/m³ when the logs were not separated. For the “self loader” system, the total cost reached 2,367 yen/m³ when stem butts and logs were conventionally separately. In this case, the total cost of the integrated system (2,394 yen/m³ integrated transport system) did not vary much from that of the “conventional” system. Therefore, although the cost of logging did not vary significantly between the “conventional” and the “integrated” harvesting systems when using the “self-loader” machinery, it was reduced by approximately 11% when the integrated system was combined with the “non-self-loader” machinery. Notably, when using open-top trucks for transport of only stem butts, the annual working days decreased to 14%–16%. Therefore, in this case, the use of the “integrated” system resulted in a cost reduction of 20%–26% compared with that of the “conventional” system for both “self-loader” and “non-self-loader” machinery. We conclude that the integrated system is advantageous even for small-scale businesses, as it allows for cost reductions even without the use of open-top trucks.

This study aimed to assess lumbar burden caused by using implements when planting containerized seedlings. This study included eight individuals using three different implements (hoe, dibble, and spade) for planting containerized seedlings on land located on two slopes (steep and gentle). Lumbar moment was measured, and results revealed that lumbar moment associated with using a hoe was larger than that associated with using other implements. Lumbar moments associated with using all implements decreased when planting seedlings on a steep slope, and thus tasks performed on a steep slope were classified as “medium heavy” tasks, which were accompanied with a low risk of lumbar disorders. However, the lumbar moment associated with using a hoe on a gentle slope was larger than that associated with using a hoe on a steep slope, and thus tasks performed using a hoe on a gentle slope were classified as “heavy” tasks and were accompanied with a high risk of lumbar disorders. The lumbar moments associated with using other implements on a gentle slope were lower than those associated with using a hoe on a gentle slope, and thus tasks performed using a dibble or spade on a gentle slope were classified as “medium heavy” tasks. We concluded that there is no difference among lumbar moments associated with using implements on steep slopes. However, the lumbar burden associated with using a dibble and spade is smaller than that associated with using a hoe on a gentle slope.