The following is the editor's condensed summary of the articles in issue 24.2.
Siberian larch from the north-western part of Russia is less sensitive to spring frost damage than larches originating from the far-east. The north-western larch provenances would therefore be better adapted to the more maritime climate in the Nordic countries. Thröstur Eysteinsson and colleagues measured frost tolerance of a large set of larch provenances planted in a Swedish field trial.
Jacob Boateng and colleagues evaluated one of the few long-term trials with site preparation in North America. Twenty-year data from the white spruce trials showed the importance of reducing competition from tall shrubs. This reduction could be obtained by mechanical site preparation or other controls of the vegetation. With site preparation or post-planting vegetation control, rotation length of the white spruce stands can be shortened by 12–16 years.
The growth and regeneration of Siberian larch and Siberian pine has responded positively to climate warming in southern Siberia. Regeneration of these species has already surpassed their historical upper elevation limits by 10–80 meters, according to a study by Viacheslav Kharuk and colleagues. The species are migrating into the former tree-less tundra, but their presence may increase the warming, since albedo decreases with a tree cover.
The forests on the Finnish side of the Finnish-Russian southern border are more fragmented with smaller forest patches and longer distance between similar forest types. On the Russian side of the border, forests have a higher share of broadleaved and mixed stands, according to a study by Petteri Muukkonen and colleagues. Their data was based on satellite images and field inventories.
Timo Möykkynen and Timo Pukkala modelled the optimal management of Norway spruce stands with respect to damage by root rot. A heavily infected stand should be thinned once, and late. The economically optimal management is dependent on the discounting rate.
Life-cycle assessments give a hint of the environmental impact from different processes. A case study on Eucalyptus plantations in Spain by Sara Gonzalez-Garcia and colleagues showed that logging operations had the highest impact on global warming, acidification and photochemical oxidant formation. Second most important was the transportation to the industry.
Logging residue for bioenergy purposes is costly to collect and transport. Raffaele Spinelli and Natascia Magagnotti showed that the recovery of logging residue could be effectively processed with a truck-mounted bundler, which bundles the residue into pieces to be handled as logs.
With prior knowledge of the interior of a log, sawmills can sort and utilize the logs more efficiently. Three-dimensional scanning and X-ray techniques are common in Swedish sawmills. In this study, Johan Skog and Johan Oja showed that a combination of the techniques could improve the prediction of heartwood content in Scots pine logs.
Mats Hannerz