Abstract:

Different tree species have different sensitivities to damages from different kinds of fungi, insects, and vertebrates. Prices of forest products from different tree species also change over time. Mixed forests provide valuable options for sequential adaptive management. An adaptive optimization model under the risk of moose damage and prices variation has been developed to determine the initial proportion of Norway Spruce and Scots Pine in a mixed-species stand that would maximize the expected net present value. The results showed that the mixed stand was superior to the pure pine stand even no risk was considered, due to the biological mixture effect. However, when the risk of moose damage was considered, the superiority of the mixed stand was increased by 5% and 24% with or without incorporating the minimum stem number requirement of the Forest Act, respectively. The superiority of the mixed stand over a pure pine stand could be further increased by 6% when the price risk and selective thinning were included, compared to that the price was fixed

Key words: forest management decisions, uncertainty, risk, adaptive optimization