Abstract:

Based on the growth yield model system of masson pine plantation established already the productivities of various site indexes (14 ~ 20) were analysed, suitable cultivation objectives of various site indices was determined.According to the differences in cultivation objectives, sites and cultivation measures, a lot of cultivation types for building timber were given.The stand quantitative, technical and economic mature ages of various cultivation types were calculated, then rational cutting ages of various site indexes were determined.The results showed that the cutting age determined in this paper was shorter 4 ~ 12 years than that being used, and that IRR was raised 3%~ 9%.The relations between cutting age and site, cultivation objectives, silvicultural condition (planting density, thinning), economic condition were studied.The quantitative, technical and economic mature ages reduced with the raising of site index, with thinning times increase, the quantitative mature age of the lower planting density stand increase, but technical mature age reduce.The economic mature age reduce with the discount rate increasing, while discount rate raise 1 %~ 2 %, the economic mature age reduce for 1 year, otherwise, the economic mature age put off about 1 year.

Key words: Masson pine, Forest plantation, Building timber, Cutting age, Model system