Economics of Douglas fir management revisited

Abstract

A recent Douglas fir management investigation is repeated in terms of accounting measures. The rotation times become much shorter than in earlier results. Thinnings do not become feasible, provided the thinning effects on the volumetric yield function do not evolve in time. Evolving prices and expenses break the periodic boundary condition in monetary quantities: profit rates and capitalizations evolve with prices. The periodic boundary condition is, however, retained in time derivatives of dimensionless quantities, as well as in physical characteristics of rotations optimized for the rate of return. Then, optimal rotations do not depend on the evolution of prices and expenses. Relatively high timber prices shorten rotations, as relatively high expenses extend them.