From the Editor
Contents in brief
The following is the editor's condensed summary of the articles in the current issue.
Insect attacks on seedlings occur occasionally in forest nurseries. Ketil Kohmann focused on the damage by a little bug, Lygus rugulipennis, which feeds on pine and spruce seedlings. He found that after 4 years attacked seedlings still had multiple leaders or other deteriorations in quality. The attacked seedlings should therefore be sorted out in the nursery.
Is there an overall threshold for the amount of dead wood to be left in the forest below which the survival of wood-living organisms is severely affected? In a review article, Thomas Ranius and Lenore Fahrig argue that no such distinct threshold can be defined, but that survival increases with increasing amount of dead wood.
Scarification disturbs the lichen mat. Reindeer eat lichen and foraging reindeer may trample on and destroy the seedlings. These intricate relationships were analysed by Samuel Roturier and Urban Bergsten. They could not detect that reindeer were eating less in scarified plots, but they found that reindeer damaged about 8% of the seedlings by trampling.
Gunilla Cassing and her colleagues studied moose browsing and demonstrated that observations from a landscape level could also provide valuable information for the stand level. For example, birch is browsed more in pine forests, where little other food is available. Rowan is browsed less when more other deciduous trees are found.
Several articles in previous issues of the journal have described the possibilities of laser scanning for forest mensuration. Matti Maltamo and colleagues show that laser scanning information can estimate crown height as accurately as plot-level information measured from the ground.
A more mathematical application of laser scanning data is presented by Steen Magnussen and his colleagues. They suggest a method called Poisson Voroni tiling for identification of tree clusters. The method can improve the accuracy of inventories.
Plans that depend on people's actions have to consider the preferences and attitudes of such people. Based on a questionnaire, Fredrik Ingemarson and his colleagues grouped Swedish private forest owners into five types with respect to their underlying values. These values influenced their management activities and should be considered by forest policy makers and advisers.
The right product for the right industry is becoming increasingly important in the forestry. However, sorting in the forest involves an extra cost and has effects on transportation logistics. Carl-Gustaf Carlgren and his colleagues developed a planning model for this issue. The model was applied to three forest companies in southern Sweden, and showed that log sorting increased costs, but that considerable reductions in transportation costs could be achieved by backhauling.
Many studies have estimated large, unused quantities of forest-based biomass in Sweden. However, there may not be as much fuel available if economic constraints are also considered. Robert Lundmark analysed the supply and found that another 12 TWh could be utilized from harvest residues; however, after this has been used it is more profitable to use roundwood for fuel. The competition between energy and forest industries is likely to increase as the demand for fuel increases.
M. Hannerz
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