A theory of red pine (Pinus koraiensis) management for both timber and commercial seeds

Red pine (Pinus koraiensis), is a commonly distributed species of tree in n ortheastern China, The wood is used for manufacturing purposes as usual, an d the seeds are used as a source of delicious food and for medical applicat ions. If the top of the tree is removed at a mature age, seed production is much enhanced. In this article, we derive optimal harvesting rules for suc h multiple use management of red pine trees. We give optimality conditions for cutting off the top of the tree, the intensity of removal, and the opti mal date for the final felling, The two harvesting dates will indirectly de termine the optimal length of commercial seed production. We also derive co mparative static results on how the rotation periods and the intensity of r emoval changes, as a function of prices and the interest rate. The theory i s also applicable to the economic management of seed orchards, where the pr actice of cutting off the top of the tree is used, all over the world, to i nduce seed production.