Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2000
Authors
Bernt-Håvard ØyenAbstract
No abstract has been registered
Authors
Erlend Ystrøm Haartveit Dag FjeldAbstract
Structural changes in the sawmilling industry imply more wood transport as distance between sawmills is increasing. One of the factors that determines the potential for economies of scale is the trade-off between reduced production costs and increased transport costs. The methods used in this study are based on geometric properties of wood procurement areas.The effects of the distribution of forest (area coefficient) and the road net (winding coefficient) upon average transport distance was explored, and considerable regional variation was found.The transport net factor (t) is the product of the area coefficient (a) and the winding coefficient (w) and gives a relative measure of the potential for efficient procurement logistics with respect to the distribution of productive forest area and the road net. The transport net factor is estimated for two wood procurement areas in each of four regions.When studying the sawlogs procurement in regions with different density of sawlogs buyers, average transport distance increases relatively more in areas where several buyers are competing for a limited timber supply than in areas with few competitors.
Authors
Bjørn ØklandAbstract
No abstract has been registered
Abstract
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Authors
Peder GjerdrumAbstract
Manuskriptet beskriver en metode og et eksempel for å beregne kostnader ved trelasttørking, presentert for Cost E15 Workshop
Authors
Tor MykingAbstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Bjørn ØklandAbstract
No abstract has been registered
Authors
Per Holm Nygaard Heleen A. de WitAbstract
Elevated concentrations of aluminium (Al) which have been hypothesized to limit root growth of forest trees as well as nutrient uptake, are believed to be a major threat to forest vitality. Direct toxicity of Al, causing decreased root growth has been observed in several nutrient solut ion studies and in some pot experiments using seedlings.However, direct support for the occurrence of decreased root growth in mature forest stands is scarce. Despite the uncertainty concerning effects of ambient concentrations of Al in soil water on fine roots, the concentrations of dissolved Al in forest soils has been assigned a key role in models used to calculate critical loads.Here we present results of three years of artificial additions of Al on fine root growth in a mature stand of Norway spruce (Piece abies). During the growing season the average concentrations of dissolved inorganic in soil water at 10-cm soil depth ranged from about 1 mol L-1 (control) to 120 mol L-1 (highest Al treatment).According to nutrient solution studies the established concentrations of dissolved inorganic Al reached levels that may be toxic. In addition, the Ca/Al ratios were well below 1.0, a value, which is regarded as a lower limit below which negative effects on vegetation may be expected.So far, no effects on fine root growth, root mortality and root distribution has been observed. Chemical analysis of the fine roots indicate a lower molar Ca/Al ratio in living fine roots of 0-20 cm depth and dead fine roots 0-40cm in the Al treatments compared to controls.Our study does not support the critical load assumption that Ca/Al 1 in soil solution is critical to fineroots, as shown by some culture solution experiments. The molar Ca/Al ratio of fine roots mainly reflect the soil chemical composition, which has a steep depth gradient So far, three years of Al additions has shown that the soilmatrix is an extremely robust growth medium, which can sustain high inorganic Al concentration and low Ca/Al ratios.The results show clearly that the value of Ca/Al or BC/Al as used in critical load calculation and plant soil modeling, may have to be reconsidered.
Authors
P.C. Evensen Halvor Solheim Klaus Høiland J. StenersenAbstract
Three clones of Norway spruce (Picea abies) were studied for their response to mass-inoculation with the blue-stain fungus Ceratocystis polonica. The effect of different pretreatments (fungal inoculation and wounding) before mass-inoculation was investigated for their possible role in an acquired resistance reaction.Pretreated trees showed enhanced resistance to the subsequent mass-inoculation relative to control trees that received no pretreatment. Furthermore, the fungal colonization of inoculated trees was less than that of wounded trees. The phenolic content of the bark, analysed by RP-HPLC, was compared in trees receiving different treatments.Trees inoculated with C. polonica had higher average concentration of ()-catechin, taxifolin and trans-resveratrol than wounded trees. Both inoculated and wounded trees had higher average concentrations of these compounds than control trees.The effect of the phenolic extract of Norway spruce bark on the growth of the root rot fungus Heterobasidion annosum and the blue-stain fungi C. polonica and Ophiostoma penicillatum were investigated in vitro. Heterobasidion annosum was not negatively affected, and the extracts had fungistatic effects on the blue-stain fungi. The growth of O. penicillatum was more inhibited than the growth of the more aggressive C. polonica.