To increase the efficiency of production of containerized seedlings of Chamaecyparis obtusa, it is desirable to sow one seed with a high germination rate per cavity. Therefore, we tested the possibility for improvement of germination rate of C. obtusa seeds by screening in water supplemented with a surfactant. The treatment which provided high rate of mature seeds, germination rate and recovery rate involved immersing the seeds in water supplemented with 0.1% surfactant for 3 to 6 hours. Seeds of 9 lines of C. obtusa were, thus, screened. Results showed that in all strains except one with initially mature seed rate as low as 2% before screening, mature seed rates was effectively increased from 17–71% to 83– 99%. Additionally, in 5 of the 9 lines evaluated, germination rates increased from 7–54% to 74–96%. Therefore, we demonstrated the effectiveness of the immersion screening method to significantly increase the mature seed rate and gain the seeds with high germination rate.

This study showed the current conditions of family forest owners with a questionnaire sent to all households in Chizu town, Tottori prefecture where was a traditional forestry area. Particularly, we paid attention to the small scale forest owners that it became impossible to grasp in the recent census of agricultural and forestry in Japan. Results are as follows. More than half of households were the family forest owners. It indicated that the forest and the forestry were important issues in Chizu town. Among the forest owners who had plantation forests, 41% of the owners had plantation forests less than 1 ha and 67% had less than 3 ha. The ownership scale of natural forests was smaller. Most of respondents were 60 years old and over, were not engaged in agriculture and forestry and had small farmland. This implied that it was difficult for them to increase efficiency of labor and capital by combining forestry and agriculture. The average management level of the owners over 3 ha were better than the others. However, there were more owners among the owners under 3 ha than among the others whose forest management condition was relatively better. The owners over 3 ha were more likely to have successors than the others.