Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2012
Sammendrag
The objective of the project Winfur (within WoodWisdomNet) was the industrial application of furfurylated wood in the window market. Because of promising results concerning the wood species European beech, common ash, radiata pine and Southern yellow pine it was decided to evaluate material from these species.The material exhibits promising wood water related behaviour. Coating tests showed the coatability with selected commercial products. Additionally, outdoor weathering tests were performed. It is also possible to produce 3-layer scantlings with common gluing systems like PVAc. The resistance against wood destroying fungi increased in a way that the material is suitable for the window application. Different investigations were performed to test the furfurylated material and the results are satisfying.The last step in the project was the production of prototypes for different investigations. The window companies reported no differences between using furfurylated wood compared to untreated wood within the production of the windows. The tests of full scale window prototypes according to seven test standards, e.g. repeated opening and closing and water tightness against driving rain were performed.The production and standardised testing of full-scale window prototypes indicates that the use of furfurylated wood will not cause any problems with fulfilling the criteria for the Scandinavian P-mark and the German RAL certificate. The overall conclusion is that furfurylated wood material is suitable for the window production.
Sammendrag
Brown-rot fungi such as Postia placenta are common inhabitants of forest ecosystems and brown rot fungi are also largely responsible for the destructive decay of wooden structures. The aim of this study was to compare two commonly used strains of Postia placenta MAD-698-R and FPRL 280. Scots pine sapwood samples were exposed for two and eight weeks to both fungal strains. The following was investigated: mass loss, fungal gDNA content and gene expression.A significant difference was found in mass loss after eight weeks between the P. placenta strains MAD-698-R and FPRL 280. MAD-698-R gave higher mass loss than FPRL 280. However, MAD-698-R seems to have a slightly slower growth rate than FPRL 280, reflected in lower gDNA content after two weeks.After eight weeks of exposure the gDNA content dropped and no significant difference was found between MAD-698-R and FPRL 280. We observed differences in mass loss, colonization-rate and gene expression between the two Postia strains. Results suggest significant differences in the regulation of key lignocellulose degrading enzymes between MAD-698-R and FPRL 280.
Forfattere
Christian Brischke Christian Welzbacher Antje Gellerich Susanne Bollmus Katharina Plaschkies Wolfram Scheiding Gry Alfredsen Joris Van Acker Imke De WindtSammendrag
Die Dauerhaftigkeit von Holz gegenber Basidiomyceten wird in Europa nach CEN/TS 15083-1 (2005) bestimmt. Die bisherigen Erfahrungen mit diesem Standard sind sehr heterogen, und Ergebnisse frherer Ringversuche teilweise nicht oder nur unvollstndig verffentlicht. Insbesondere die Notwendigkeit einer natrlichen Vorbewitterung der Prfkrper, u.a. mit dem Ziel einer Detoxifizierung des Materials, wird kontrovers diskutiert. Fnf europische Forschungseinrichtungen haben sich deshalb zu einem neuen Ringversuch zusammengeschlossen, in dem die Dauerhaftigkeit gegen holzzerstrende Pilze von fnf Holzarten mit und ohne Auswaschbeanspruchung bzw. 6-monatiger natrlicher Vorbewitterung gegen Coniophora puteana und Trametes versicolor geprft wurden. Es ergaben sich Unterschiede in der Dauerhaftigkeitsklassifizierung zwischen den Prfinstituten (bis zu vier Klassen) sowie in Abhngigkeit von der Vorbeanspruchung und den statistischen Auswertungsgren. Die natrliche Vorbewitterung der Prfkrper hatte teilweise eine Angleichung der Dauerhaftigkeitsklassifizierung zwischen den Prfinstituten zur Folge. In allen Fllen wurde eine Homogenisierung der Dauerhaftigkeitseinschtzung durch Vorbewitterung jedoch nicht erreicht. Generelle Aussagen zum Einfluss der Vorbeanspruchung auf die Klassifizierung der Dauerhaftigkeiten lieen sich somit nicht ableiten, weshalb diese weder zwingend zu empfehlen noch abzulehnen ist.
Sammendrag
I en kronikk i Nationen 20. mars kommer Rune Aanderaa i Sabima med kritikk av en nylig publisert rapport om miljøhensyn i norsk skog. Aanderaa behandler i sin kronikk vår rapport som et politisk innspill i den pågående debatten om skogvern og beskyttelse av biologisk mangfold. Dette er feil. Rapporten tar ikke standpunkt til spørsmål relatert til økt eller redusert behov for miljørestriksjoner og vern i norsk skogbruk, og er ikke et politisk innspill. Rapporten presenterer et tallgrunnlag som bør ligge til grunn for en nødvendig debatt om fremtidig forvaltning av norske skogressurser.
Sammendrag
Med politiske målsettinger om økt avvirkning og økt trebruk er det viktig at en har kjennskap til hvor stor del av ressursene som reelt danner grunnlaget for virkestilgangen. Nye beregninger viser at om lag 30 prosent av det produktive skogarealet i Norge er underlagt moderate eller sterke restriksjoner grunnet miljøhensyn. Per i dag representerer dette en båndlegging av om lag 15 % av stående volum.
Sammendrag
Phytosociological studies can be an important tool to detect temporal vegetation changes in response to global climate change. In this study, we present the results of a resurvey of a plot-based phytosociological study from Sikkilsdalen, central Norway, originally executed between 1922 and 1932. By using a detailed phytosociological study we are able to investigate several aspects of elevational shifts in species ranges. Here we tested for upward and downward shifts in observed upper and lower distribution limits of species, as well as changes in species optima along an elevational gradient, and related the observed range shifts to species traits that could explain the observed trends. More species shifted upwards than downwards, independently of whether we were investigating shifts in species\" upper or lower distribution ranges or in species optima. However, shifts in species upper range margins changed independently of their lower range margins. Linking different species traits to the magnitude of shifts we found that species with a higher preference for prolonged snow cover shifted upwards more in their upper elevational limits and in their optima than species that prefer a shorter snow cover, whereas no species traits were correlated with the magnitude of changes in lower limits. The observed change in species ranges concord both with studies on other mountains in the region and with studies from other alpine areas. Furthermore, our study indicates that different factors are influencing species ranges at the upper and lower range limits. Increased precipitation rates and increased temperatures are considered the most important factors for the observed changes, probably mainly through altering the pattern in snow cover dynamics in the area.
Sammendrag
Wood for outdoor decking has a high market share in the Nordic and Baltic countries among private house owners. Important issues for the consumer are maintenance intervals and aesthetic appearance as well as decay resistance. Knowledge and consumer information about these aspects are required to ensure that wood can compete with alternative decking materials. In this paper an accelerated testing of decking, “stapelbädds metoden”, was evaluated after ten years of exposure at Ås, Norway. The test method covers different hazard situations within use class 3. Different preservatives and wood modification treatments were used in addition to untreated Scots pine (sapwood and heartwood) and larch (heartwood). The samples were treated with two different surface treatments. In addition there was one set without any surface treatment. Fungal discoloration and decay was evaluated. This provided new information about performance both on and above ground for a range of different combinations of preservative/modified systems and surface treatments of wood in decking for outdoor use. Generally, there were no significant differences in performance between the surface treatments, both with regard to surface discolouring fungi and decay fungi. For all surface treatments, the samples with rating 3 (heavy attack) in bottom layer in one or several stacks was: Tanalith M, Tanalith M (c), Gori Pres 10, Scanimp, styren, furfurylation, thermal modification, Ultrawood, larch heartwood, pine heartwood and pine sapwood. For all surface treatments, the samples with mean rating ≤ 2 (evident attack) in top and middle layer in one or several stacks was: ACQ 1900, Wolmanit CX 8, Tanalith E7, Gori SC 100, Royal, Royal with pigment, Scanimp, styrene and larch heartwood
Forfattere
Holger LangeSammendrag
We calculate entropy and complexity of runoff time series and artificially generated series with long-range correlations. Entropy and complexity of data series may be represented against each other in a two-dimensional diagram which we will refer to as Complexity-Entropy Causality Plane, or CECP. We use a recently developed framework for these two indicators based on order statistics. It is well-known that runoff, as all other environmental time series actually measured, is a mixture of deterministic (signal) and stochastic (noise) parts, the latter due to noise inherent in the measurement process and externally induced by natural processes. The distinction between signal and noise is notoriously difficult and subject to much debate. In our approach, the observed series are compared to purely stochastic but long-range correlated processes, the k noise, where k is a parameter determining the strength of the correlations. Although these processes resemble runoff series in their correlation behavior and may be even tuned to any runoff series by changing the value of k, the CECP locations and in particular the order pattern statistics reveals qualitative differences between runoff and k noise. We use these differences to conclude on the deterministic nature of the (short-term) dynamics of the runoff time series. The proposed methodology also represents a stringent test bed for hydrological models.
Sammendrag
Genomic sequencing gives us a tool to systematically and rapidly discover novel genes, how their products function in the cell, and explore their interactions. When the DNA sequences are known, primers can be designed to detect transcripts of genes with gene products related to basic cellular processes and hyphal growth. The characteristic gene products induced in different fungi by different wood protection systems during decay can be identified. This knowledge will give us a better understanding of the fungal degradation of wood and we can optimize wood protection systems. Hence, no single technique will give us the answer to all questions about the decay of wood we need to gather small pieces of the puzzle using different approaches. The aim of the present study was to investigate the effects of acetylation level on the growth of Postia placenta with regard to amount of total DNA and gene expression targeting six different genes. This paper presents preliminary results after 36 weeks of incubation. We found no mass loss in the acetylated samples treated to a high treatment level after 36 weeks of incubation in a modified monoculture soil-block test. The presence of P. placenta DNA and the absence of mass loss could indicate on an inability of the mycelia to establish a wood exploitation phase. The results also showed that P. placenta increased the expression of AlO (involved in production of H2O2), cytochrome P450 (related to breakdown of toxic compounds), and QRD (involved in generating biodegradative hydroxyl radicals via redox cycling) along the incubation time, growing on acetylated wood treated to a high treatment level.
Sammendrag
Groundwater pollution by agrochemicals, degradation of soil quality and pollution of aquatic ecosystems by agricultural drainage waters have become an issue in the last decades. Flow processes in the vadose zone are closely related to these problems. In general, water flow in soils can be classified into two major categories: uniform and non-uniform (preferential) flow (In: U.S. National Committee for Rock Mechanics, Conceptual Models of Flow and Transport in the Fractured Vadose Zone, 2001, pp.149-187). The former describes a relatively slow movement of water through the porous soil matrix and can be modelled by Richard”s equation. The latter comprises all flow types where water bypasses a portion of the soil matrix and flows through localised (i.e. preferential) paths. Unlike uniform flow, preferential flow is hardly predictable because the assumptions of Richard”s equation of a homogeneous representative elementary volume characterised by a single value of water potential, water content and hydraulic conductivity are frequently violated (Eur J Soil Sci, 2007; 58:523-546)....