Optimum juvenile density, harvesting, and stand structure in even-aged Scots pine stands

The economics of timber production is studied using empirical data for various juvenile densities and a distance-independent individual-tree growth model specified for Finnish Scots pine (Pinus sylvestris [L.]) stands. Our results imply that explicit inclusion of quality effects on prices increases optimum juvenile density. In addition, quality effects make economic surplus of forestry more sensitive to variations in juvenile density. Optimum thinnings remove trees that have no prospects for high relative value growth. Optimum thinnings are selective thinnings that remove inferior-quality trees, some of the smallest trees and, contrary to conventions, those of the largest trees that fulfill the sawlog dimensions. Thinnings removing trees strictly above and/or below certain tree diameters homogenize the remaining growing stock by narrowing the diameter distribution. Homogeneous stand structure is economically favorable at final clearcutting because the stand can be clearcut promptly after the majority of trees have reached sawlog dimensions and have experienced the last high peak in value growth.