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Research article2005Peer reviewed

Reducing forest fragmentation in long-term forest planning by using the shape index

Ohman K, Lamas T


The fragmentation of old forests is an aspect of forest development that has to be considered in long-term forest planning. Although several measures of the spatial structure of forests have been reported in the literature, very few have been evaluated with respect to their usefulness in long-term forest planning. The objective of this study was, therefore, to investigate if it is possible to use of one of these measures, the shape index, as a criterion in the optimization model for decreasing the fragmentation of old forest in the landscape The shape index is evaluated by solving a two-objective problem with simulated annealing, which aims at maximizing the net present value and minimizing the shape index for a landscape consisting of 924 stands. In a case study, the stated problem was converted to a one-objective problem by weighting the two objectives together. The study showed clear differences in the spatial patterns of old forest between the different weight combinations. With a higher weight on the shape index, the old forests become more clustered and the number of small and isolated patches of old forest decrease compared with a low weight on the shape index. The results also indicate that it is possible to considerably improve the shape index with only a small sacrifice in net present value. It is also clear from the case study that the shape index is a computationally well-behaved measure to use in optimization. The solution times for the different cases were generally very short. (c) 2005 Elsevier B.V. All rights reserved

Published in

Forest Ecology and Management
2005, Volume: 212, number: 1-3, pages: 346-357