Applying the MOTTI simulator to analyse the effects of alternative management schedules on timber and non-timber production

Abstract

The effects of three forest management alternatives on stand development were simulated using the MOTTI stand simulator, a stand-level analysis tool developed for multiple-purpose forestry planning. The simulation results were used to analyse the effects of different management schedules on wood production, profitability, carbon sequestration and biodiversity. Stand data from a 35-year-old Norway spruce ( Picea abies (L.) Karst.) dominated stand with a deciduous admixture were used as the starting point. Stand development was simulated for a period of 35 years, and additionally for 65 years for biodiversity analyses. The three management alternatives were—(1) pure spruce stand: two commercial thinnings with removal of deciduous admixture, regeneration at 70 years, goal to maximize wood production; (2) mixed stand: as the previous one, but the deciduous admixture was maintained throughout the rotation, goal to enhance biodiversity; (3) unmanaged: no treatments. The pure and mixed alternatives including commercial thinnings outperformed the unmanaged one both in the production of merchantable wood and in profitability (value of standing stock for the unmanaged alternative), but did not notably differ from each other. Carbon sequestration was directly proportional to biomass production and thus highest in the unmanaged alternative. The mixed stand had a 50%, and unmanaged stand 88% higher species richness than the pure stand at the age of 70 years. Prolonging the rotation to 100 years also considerably increased the species richness. The applicability of the results and use of the MOTTI simulator in forestry planning are discussed.