近藤 洋史 森林総合研究所, 九州支所・育林経営部, 主任研究官
寺岡 行雄 鹿児島大学, 農学部, 講師 (40264105)
YOSHIMOTO Atsushi Inst.of Statistical Mathematics, Dept.of Stat.Methodology, Associate Professor, 調査実験解析研究系, 助教授 (10264350)
KOBAE Shoitchiro Miyazaki Univ., Dept.of Ag.& For.Econ. Professor, 農学部, 教授 (10038276)
KONDO Hiroshi Forest and Forest Product Research Inst., Kyushu Branch, Senior Researcher
|Budget Amount *help
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 2000 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1999 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1998 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1997 : ¥1,300,000 (Direct Cost : ¥1,300,000)
The objective of the project was to conduct quantitative analysis on forest resource management along with environmental conservation and economic development in mountainous areas. Our results are :
1. Cost analysis : Under the current level of timber price level, silvicultural and harvesting practices may not be carried out. With use of subsidies there still remains difficulty for replantation. As a result, it will be necessary to renew and modify the subsidy policy in order to achieve our sustainable forest resorce management.
2. Optimal thinning regime : With use of the proposed dynamic programming model, management effect of subsidy on thinning was revealed. The more the subsidy, optimal rotation age tends to be longer, ending up to 40 years. Changing discount rate from 1 to 3%, large effect was observed for 1 and 2% as compared to almost no effect for 3%.
3. Timber demand/supply modeling : In Miyazaki as one of the largest sugi producing states, relative price elasticity of domestic lumber demand was -4.6, very elastic. In Iwate, relative price elasticity of log demand was -0.29. Shizuoka, which is close to the major timber consuming states, showed better results on timber supply.
4 Forest resource management : Based on the current forest stocking level, we analyzed how much of timber supply could be expected on the sustainable fashion over time by use of the LP based harvesting model. In Miyazaki, allowing 10% change in harvest flow period by period, periodical (5 years) harvest level became 9490,000 m^3, which that was 2095,000 m^3 for Hiroshima under 30% allowance. This is because in Hiroshima infrastructure for production is not well developed as opposed to the major timber producing states, e.g., Miyazaki, and also because a large amount of US logs is imported, implying no necessity of improvement for domestic timber producing environments.