Economic analysis of timber management practices promoting preservation of biological diversity

The effects, in terms of economic value and harvest potential, of adopting restricted timber management practices promoting the preservation of biodiversity are analysed in a 5620 ha boreal forest landscape in southeast Norway. A forest management model based on ecological principles aiming at preservation of biodiversity, e.g. by adopting restricted silvicultural treatments imitating the effects of natural processes, such as forest fires, is applied. The forest area is divided into four separate classes reflecting the probabilities of forest fires, and different treatment options are assigned to each of the classes. These options comprise extended rotation periods and treatments such as clear‐cutting with retention of seed trees and shelterwood cutting. A management problem specified as maximization of net present value subject to a requirement to preserve (medium term) about 10% of the forest area for a period of 70 yrs is solved by means of linear programming. Compared with current timber management practices, the net present value of the restricted management problem is reduced by 14% (15%) for a real rate of discount of 3% (4%) pro anno. The annual harvest flow is reduced by 11–33%. For a management problem comprising even‐flow harvesting constraints in addition to biodiversity constraints, the net present value is reduced by 16% (19%).