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.
2007
Authors
Clemens Reimann Arnold Arnoldussen Tor Erik Finne Friedrich Koller Øystein Nordgulen Peter EnglmaierAbstract
Forty samples each of leaves, bark and wood of mountain birch (Betula pubescens EHRH.) were collected along a 120 km long south-north transect running through Norway\"s largest city, Oslo. Concentrations of 26 chemical elements (Ag, As, Au, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sr, Ti and Zn) as well as loss on ignition for the three sample materials are reported. By far the highest concentrations of most elements appear in the leaves. Prominent exceptions are Au and Pb, both of which are enriched in wood, indicating the importance of root-uptake, and As which is enriched in bark. Bedrock lithology, ore occurrences, soil pH and urban contamination all have a visible influence on the element concentrations in mountain birch leaves, bark and wood. It is often impossible to differentiate between all the factors that can influence element concentrations in the three sample materials. Mountain birch bark shows the strongest anthropogenic impact of the city of Oslo for dust-related elements (Fe, La, Ti) and Sb. Even in mountain birch bark the influence of the city on element concentrations is no longer discernible from the background variation at a distance of less than 20 km from Oslo centre. Compared to terrestrial moss, mountain birch appears to be of little value as a biomonitor for urban contamination.
Authors
Peder GjerdrumAbstract
Predicting the yield and quality of sawn timber continues to be a challenging task, influenced by several stochastic processes: Log dimension and shape under bark varies, accuracy of sawing is not perfect, etc. This work presents an annotated model based on an approach successfully applied in the industry through a couple of decades. A number of important timber yield predictors are identified, and the following models give unbiased yield estimates. Being in need of adjustment before transferring to new locations, the approach might be considered a powerful tool to analyse and improve the operation, rather than a complete model in itself. Nevertheless, the notional, purely geometric, models might be superior for analysing unfamiliar sawing patterns, even if they tend to overestimate the yield. Thus, the two methods should preferably be used in combination, rather than one replacing the other. Finally, the everyday use of such models is illustrated and a procedure for associating sawn timber with suitable logs is outlined.
Authors
Clemens Reimann Arnold Arnoldussen Rognvald Boyd Tor Erik Finne Friedrich Koller Øystein Nordgulen Peter EnglmaierAbstract
Forty samples each of leaves of birch (Betula pubescens Ehrh.), European mountain ash (Sorbus aucuparia (L.)) and bracken fern (Pteridium aquilinum (L.) Kuhn) as well as spruce needles (Picea abies (L.) Karsten) were collected along a 120 km south–north transect running through Norway\"s largest city, Oslo. Concentrations of 25 chemical elements (Ag, Au, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sr, Ti, and Zn) as well as loss on ignition for the 4 sample materials are reported. The decline of input of sea spray with distance from the coast, geology, pH and anthropogenic contamination all played a role for the observed element concentrations in the leaves. Although growing under exactly the same natural conditions each plant species displayed quite unique uptake characteristics. Plant-species dependency and individual differences in the reaction of the plant leaves to different element sources make the investigated species of very limited value as bioindicators of anthropogenic activities. Anthropogenic contamination influences plant-leaf element content within a limited distance ( 20 km) from the source.
Authors
Peder Gjerdrum Mauro BernabeiAbstract
Resin pockets, being an important natural characteristic for wood quality and tree physiology, were observed on the surfaces of boards sawn from four large Norway spruce (Picea abies (L.) Karst.) trees and analysed for size and distribution. Axial length varied between trees and increased from pith to surface and from butt to top; however, three quarters of the variation were random and normally distributed. Also resin pocket frequency varied between trees. Within the stem, the resin pockets remained independent and randomly distributed following the exponential distribution in all three directions: radial, angular and axial, corresponding to a constant probability during the lifespan of the tree. No association between size and frequency was identified. The initiation and the expansion of a resin pocket appear to be controlled by two different physiological processes. The findings should add to the understanding of resin pocket formation in spruce and should be applicable to wood quality
Authors
Anna Arneberg Per Holm Nygaard Odd Egil Stabbetorp Bjarni D. Sigurdsson Edda Sigurdis OddsdóttirAbstract
The aim of this study was to investigate variation in decomposition and vegetation due to afforestation. The ICEWOODS sites containing stands of different tree species and age in the western (Skorradalur) and eastern (Hallormsstaður) parts of Iceland were investigated during the summer of 2004. These stands were compared with treeless pastures. The planted stands represent chronosequences, i.e., different age classes within each tree species were studied. Decomposition was studied by a cotton strip assay. Cotton strip decomposition increased with incubation time and decreased with soil depth. The tree species can be ranked according to increasing decomposition in the following series: lodgepole pine < Sitka spruce< Siberian larch < mountain birch. In general, decomposition decreased with increasing age of the stands...
Authors
Clemens Reimann Arnold Arnoldussen Peter Englmaier Peter Filzmoser Tor Erik Finne Robert G. Garrett Friedrich Koller Øystein NordgulenAbstract
Rock samples and the C-, B- and O-horizons of soils developed on these rocks were collected in forested areas along a 120-km south–north transect in southern Norway, passing through the city of Oslo. Forty samples (1 site/3 km) were analysed for 37 chemical elements (Ag, Al, As, Au, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sc, Se, Sr, Te, Th, Ti, Tl, U, V, W and Zn) following an aqua regia digestion; pH (water extract) and loss on ignition were also determined. The O-horizon soils were additionally analysed for Pt. Gold is the only element that shows a clear anthropogenic peak in the O-horizon soils collected from the city of Oslo. Silver, Au, Bi, Cd, Hg, Pb, S, Sb, Se and Sr all show a strong enrichment in the O-horizon when compared to the underlying C-horizon or the bedrock along the full length of the transect. Neither geology nor anthropogenic input of elements dominate the observed patterns. The most important factors for the observed element concentrations in the O-horizon are weathering, uptake (or rejection) of elements by plants and the kinetics of decay of the organic material in the O-horizon. Climate, especially temperature and precipitation, has an important influence on the formation and decay rates of the organic soil layer. Acid precipitation will delay the decomposition of the organic layer and lead to a natural enrichment of several metals in the O-horizon. Land use change, deforestation and liming can all increase the decay kinetics of organic matter and thus result in a release of the stored element pool.
Abstract
The aim of this study was to use Energy-Dispersive X-ray Spectroscopy (EDS) to localize chitosan in the cell wall of chitosan impregnated Scots pine. It is of both general and specific interest to investigate the concentration of chitosan in the wood matrix to gain further knowledge and understanding of chitosan as a wood protective system.After deacetylation, chitosan was re-acetylated with chloroacetic anhydride to achieve a covalent bonding of chloride to the chitosan polymer. Chloride labeled chitosan was measured by EDS using a Scanning Electron Microscope (SEM) and described in apparent concentration of chloride. Analysis for free chloride anions was tested by dialysis and ion chromatography.There was a significant correlation between the molecular weight of chitosan and the apparent concentration of covalent bonded chloride to the chitosan polymer. High molecular weight chitosan showed a better interaction with the cell wall structure than low molecular chitosan.
Authors
Arne Fjellberg Per Holm Nygaard Odd Egil StabbetorpAbstract
No abstract has been registered
Authors
Lone Ross Gobakken Kolbjørn Mohn JenssenAbstract
No abstract has been registered
Authors
Wim de Vries G.W.W. Wamelink Gert Jan Reinds H.J.J. Wieggers J.P. Mol-Dijkstra J. Kros Gert-Jan Nabuurs A. Pussinen Svein Solberg Matthias Dobbertin Daniel Laubhann Hubert Sterba M. van OijenAbstract
No abstract has been registered