Published Date
Forest Ecology and Management 30 March 2007, Vol.241(1):243–257,doi:10.1016/j.foreco.2007.01.008
Author
Jordi Garcia-Gonzalo,
Heli Peltola
Ane Zubizarreta Gerendiain
Seppo Kellomäki
University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland
Received 26 May 2006. Revised 7 November 2006. Accepted 11 January 2007. Available online 15 February 2007.
Abstract
A process-based model was used to assess the sensitivity of timber production and carbon (C) sequestration to the structure (in terms of age class distribution) of a boreal forest landscape and to the management under changing climatic conditions. Moreover, an approach to calculate the cost of C sequestration, through C sink enhancement, was used by computing the potential loss in the net present value (NPV) of timber when management with maximum C stock is chosen.
Regardless of the climate scenario and initial age class distribution used, management had a clear effect on the mean C stock in the forest ecosystem. Any management regime allowing a higher tree stocking than business-as-usual management increased the timber production and simultaneously maintained or increased the C stock in the forest ecosystem. On the other hand, the maximum C stock in the forest and the lowest NPV were observed when no thinning was applied before the final cut. The changing climate increased forest productivity and also C stock. When using the same management for the entire management unit, the initial age class distribution had a large influence on the results of timber production (up to 20% difference) but not on C stock in the forest ecosystem (3%).
Published Date
Forest Policy and Economics January 2005, Vol.7(1):39–52,doi:10.1016/S1389-9341(03)00010-8 Author
Wenchao Zhou,
Peichen Gong
Department of Forest Economics, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
Received 15 March 2002. Revised 18 November 2002. Accepted 3 February 2003. Available online 18 April 2003.
Abstract This paper examines the tradeoffs between different uses of forests in three communes in the mountain region in northern Sweden. The most important uses of the forests include timber production, preservation of biodiversity, reindeer grazing and recreation. Management outcomes with respect to the different uses are measured in terms of the net present value (NPV) of timber production profits, the sum of deadwood volume over time, the minimum periodic lichen production, and a minimum periodic recreation index (RI). The analysis shows that the forests can be managed to achieve dramatically different mixes of NPV, deadwood volume, and lichen production, whereas the RI varies only within a narrow range. To maximize the NPV, lichen production would reduce by 40% from its maximum level, and the volume of deadwood would be close to 0 in period 2 and thereafter. Maximization of deadwood volume would lead to the maximum lichen production, while the NPV would fall below 0. Maximization of lichen production reduces the NPV by at least 20%, and could reduce the amount of deadwood by up to 75%. When lichen production is restricted to its maximum, there is a wide range of possible choices with respect to the mix of the NPV and deadwood volume. The marginal cost of increasing the deadwood volume ranges from 1.12 to 20 SEK/m3. The choice between lichen production and deadwood volume is most flexible when the NPV is fixed at approximately 93% of its maximum. Keywords
Published Date
Information Sciences 1 February 2005, Vol.169(3):329–364,doi:10.1016/j.ins.2004.05.007 Author J.N. Sheen, Department of Electrical Engineering, Cheng-Shiu University, No. 840, Chengcing Rd., Niaosong Township, Kaohsiung County, Taiwan Received 24 July 2003. Revised 13 May 2004. Accepted 17 May 2004. Available online 12 January 2005. Abstract This paper derives fuzzy profitability models for the financial evaluation of different demand side management (DSM) alternatives. The present value of cost (PVC) and equivalent uniform annual cost (EUAC) models are selected to determine the least-cost solution, while the net present value (NPV), pay back year (PBY) and benefit/cost ratio (BCR) models are proposed for the execution of cost–benefit analysis. Since fuzzy results are in the form of a complex non-linear representation, and do not always provide a totally ordered set in the same way that crisp numbers do, the current paper approximates the resulting fuzzy profitability indexes by a triangular fuzzy number initially, and then uses the Mellin transform to obtain the means and variances of the approximated fuzzy numbers in order to determine their relative ranking in a decision-making process. The performance of the proposed models is verified through the simulation of a numerical example and by considering their application to two practical DSM programs in Taiwan. In the first case study, the fuzzy least-cost solution is used to decide upon the installation of either a conventional air conditioning system or a cooling energy storage (CES) air conditioning system. In the second case study relating to cogeneration, a fuzzy cost–benefit analysis is applied to compare the relative profitabilities of an Extracted Condensing Steam Turbine Generator system and a Backpressure Steam Turbine Generator system. These investigations confirm not only that the results of the proposed fuzzy economic models are consistent with those of the conventional crisp models, but also demonstrate that the proposed methods represent readily implemented possibility analysis tools for use in the arena of uncertain financial decision-making. Keywords
