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.
2009
Forfattere
Aldo Marchetto Rosario Mosello Gabriele A. Tartari John Derome Kirsti Derome Nils König Nicholas Clarke Anna KowalskaSammendrag
A Working Ring Test (WRT) was organised within the framework of the EU/Life+ FutMon Project (`Further Development and Implementation of an EU-level Forest Monitoring System`, LIFE07 ENV/D/000218), to evaluate the overall performance of the laboratories responsible for analysing atmospheric deposition and soil solution samples in European forests, and to verify improvements in the analytical quality resulting from the QA/QC work carried out in the laboratories which participated in previous WRTs organized in the framework of the UN/ECE ICP Forests Monitoring Programme. The WRT was carried out in accordance with International ISO and ILAG guide proficiency test both for sample preparation and numerical elaboration of the results. Four natural atmospheric deposition and soil solution samples and 4 synthetic solutions were distributed to 44 laboratories for analysis using their routine methods for the following variables: pH, conductivity, calcium, magnesium, sodium, potassium, ammonium, sulphate, nitrate, chloride, total alkalinity, total dissolved nitrogen (TDN), dissolved organic carbon (DOC). Two tolerable limits were defined for each variable on the basis of the measured value, the results of previous WRTs, a comparison with the Data Quality Objectives of other international networks, and the importance of the variable in deposition and soil solution monitoring. In the ring test 16% of the results from all the laboratories did not fall within the tolerable limits. This enabled us to identify those variables and laboratories for which improvements in analytical performance are required. The results of the exercise clearly show that the use of data check procedures, as described in the ICP Forests manual for sampling and analysis of atmospheric deposition, makes it possible to detect the presence of inaccurate or outlying results, and would therefore greatly improve the overall performance of the laboratories. Some of the analytical methods used by individual laboratories were found to be unsuitable for the samples included in this WRT, and therefore also for the routine analysis of atmospheric deposition and soil solution samples in European forests. These methods included outdated methods, such as turbidimetry or nephelometry for the determination of sulphate, silver nitrate titration and ion selective electrode for chloride, Kjeldahl digestion for the determination of ammonium and organic nitrogen, and colorimetric titrations for alkalinity. A detailed discussion of the determination of total alkalinity is also given in the report because this variable was associated with the most analytical problems.
Forfattere
Martin Lorenz Richard Fischer Georg Becher Volker Mues Oliver Granke Tatyana Braslavskaya Alexey Bobrinsky Natalia Lukina Nicholas Clarke Zora Lachmanová Claus SchimmingSammendrag
Of the 41 countries participating in ICP Forests, 27 countries reported national results of crown condition surveys in the year 2008 for 210 964 trees on 14 786 plots. The transnational result on the European-wide scale relied on 111 560 trees on 5 002 plots of the 16 x 16 km grid in 25 out of 35 participating countries. Mean defoliation of all sample trees of the transnational survey was 20.2%. Of the main species, Quercus robur and Q. petraea had by far the highest mean defoliation (24.9%), followed by Fagus sylvatica (19.4%), Picea abies (19.3%) and Pinus sylvestris (18.2%). These figures are not comparable to those of previous reports because of fluctuations in the plot sample, mainly due to changes in the participation of countries. Therefore, the long-term development of defoliation was calculated from the monitoring results of those countries which have been submitting data since 1990 every year without interruption. In the period of observation the species group Quercus ilex and Quercus rotundifolia shows the severest increase in defoliation, with 10.3% in 1990 and 21.2% in 2008. A similar increase in defoliation, namely from 11.1% to 20.4%, was experienced by Pinus pinaster. Defoliation of these Mediterranean species is largely attributed to several summer drought events. Defoliation of Fagus sylvatica increased from 17.9% to 19.7%. In contrast, Picea abies, Quercus robur and Quercus petraea and in particular Pinus sylvestris recuperated from peaks in defoliation in the mid 1990s. The spatial and temporal variation of bulk deposition and throughfall of sulphate, nitrate, ammonium, calcium, sodium and chlorine was analysed as a basis of ongoing and future studies. Between 174 and 302 intensive monitoring plots were involved in the study. Mean deposition of the years 2004 - 2006 shows spatial patterns reflecting partly regional emission situations. The temporal variation was calculated for the period 2001 - 2006. Sulphur throughfall decreased from 6.0 kg ha-1 yr-1 in 2001 to 4.5 kg ha-1 yr-1 in 2006. Bulk deposition of sulphur shows a similar decrease at a lower level, namely from 4.9 kg ha-1 yr-1 in 2001 to 3.6 kg ha-1 yr-1 in 2006 (corrected for sea salt input). Nitrogen deposition shows a less pronounced rate of decrease.
Forfattere
Lone Ross GobakkenSammendrag
Mould growth on exterior coated cladding façades is an undesirable element; it is considered to be major maintenance concern and will often shorten the aesthetical service life of the façade. On the other hand, rapid colonisation and colour change of unpainted wooden claddings is often anticipated and used as a design element. Wood is a biological building product, and individual components in a building will vary in appearance, properties and performance. Life expectancy of wood and wood-based products is related to a number of factors. Mould growth on painted surfaces is influenced by type and concentration of film fungicides, the paint formulation and the wood material, and wooden cladding may experience exponential fungal deterioration caused by variation in the climatic factors, often within a small limited area. The overall objective of this thesis was to gain in-depth knowledge about which factors influence surface mould growth on coated and uncoated wooden cladding in an outdoor environment, with a special attention to modified wood substrates. The work included identification of fungal species on the surface of coated substrates, studies of modified wood substrates\" susceptibility to mould growth, investigation of paints with different physical surface structures and their influence on surface mould growth, identification and quantification of factors that contribute to variation in surface mould growth and prediction of future performance of combinations of wood substrates and coating systems.....
Sammendrag
One of the main challenges for modified wood and modified wood based WPCs (Wood Plastic Composites) is to predict accurate service life time in UC3 (Use class 3, above ground) and UC4 (in soil or fresh water contact). So far, data from in-service conditions are rare, while several studies have evaluated the durability in lab or field test exposure. However, there is still a lack of studies comparing replicate modified wood products in both field and lab exposure. This study evaluates the efficacy of modified wood and modified wood based WPCs in AWPA E10, three different types of soil in lab (ENV 807), three test fields in-ground (EN 252) and two test sites close to ground (horizontal double layer test)......
Sammendrag
Wood is a traditional building material but in general it underlies restrictions in outdoor applications due to its respective durability against microbiological decay. To face this problem, different impregnation systems are applied to enhance the materials\" servicelife. Scots pine (Pinus sylvestris) is the most widely distributed pine in Eurasia and hence easily available. Despite of the previously defined good treatability of Scots pine sapwood, large differences in treatment performance are reported from industry. As process parameters are always adjusted to the material most difficult to treat, permeability variations in wood material are an economical problem. Therefore, it is important to understand the material in order to make a more reasonable material selection possible.....
Sammendrag
The durability of wood in exterior use is limited by to climatic factors and wood deteriorating organisms. The natural durability of the Nordic wood species is generally regarded as low, and for e.g. decking and use in soil contact wood protection is needed. Within the last years, new non-biocidal treatments, like wood modification systems, have been developed to improve the biological resistance of wood. For information about the decay resistance of untreated and modified wood, natural outside exposure is necessary. European standard EN 252 is the main field test method for use class 4. In use class 3 the need of new or improved test setups has been put forward. Traditionally evaluation of field trials has mainly been based on visual evaluation and pick-test. However, to get in depth knowledge about: 1) different field trial methods and 2) fungal colonization of new wood protection systems, additional assessment methods can be used. Hence, comparative studies are needed.....
Sammendrag
New environmental benign wood protection agents often come from natural resources, and are sometimes a waste product. Chitosan, a derivative from chitin which is among other sources a by-product from the shellfish industry, is tested as well as known wood protection agents and their synergetic effect with chitosan. The objective of the research presented in this paper, is to describe the leaching properties of the following compounds: Chitosan, chitosan/copper, chitosan/boron and chitosan/ScanImp (a commercial wood preservative). A leaching procedure was performed on treated Scots pine sapwood samples. The four solutions have also been tested with and without post treatment. A new effective fire preservative has been included in the test. Common wood preservatives have been tested as references. The combination with chitosan did improve the fixation of the wood protection agent ScanImp. Furthermore, the post treatment of the chitosan treated samples did significantly reduce the leaching of glucosamine and to some extend also the leaching of boron.
Forfattere
Peder GjerdrumSammendrag
Wood products are typically produced in ‘break-down and sorting’ processes: stems are cross-cut and sorted into saw-, pulp- and energy-logs; sawlogs are sawn to boards and sorted according to quality, then split again and applied in various ways. Through the sorting processes, the ‘group traits’ become increasingly more homogeneous, but any individual identity or origin is lost after each process. ‘Group identity’ is even the method for the popular and much applied timber certification systems. ‘Individual identity’ should be an option, however, if the industry wants e.g. to send some specific information together with the wood pieces to subsequent processes, or the answer to questions like ‘what was the outcome of products and profitability of a given lot of raw material?’
Forfattere
Øystein Johnsen Igor A. Yakovlev Carl Gunnar FossdalSammendrag
Temperature during zygotic and somatic embryogenesis regulates an epigenetic memory in Picea abies. Conditions colder than normal advance the timing of bud burst and bud set, whilst temperatures above normal delay the onset of these processes. The long-lasting memory affects growth and hardiness in the field. We made a search of candidate genes and micro RNAs that could regulate the memory, using specialized library sequencing approaches. Two subtracted cDNA libraries, representing genes that are mainly expressed in plants from a cold (CE) or a warm (WE) embryogenesis, revealed considerable differences in the transcriptomes. Many contigs were unknown. We used qRT-PCR to demonstrate that five genes with no matching in the database were differentially expressed in close correlation with the memory-induced differences in bud set. Partial sequencing of two concatemerized small RNA libraries revealed 199 different small RNAs, with predominant length of 21-nt. We found 24 novel candidate miRNAs among them, and 4 described earlier. Most of the predicted miRNA targets were related to unknown and “no-hit” genes, 5 target different disease-related genes, and 4 contigs were homologous to described functional genes. Using qRT-PCR we confirmed that three selected genes regulated by miRNAs pab-miR100, 175 and 176, could to be involved in the memory regulation. Additionally, several novel miRNAs; pab-miR080, 105, 119, 122, 132, 144a,b and 157 were differentially expressed between epigenetically distinct plants. Our data illustrates that micro RNAs will guide us to candidate genes that are putative elements in the epigenetic machinery, regulating the long-lasting memory that affects adaptive traits in this species.
Sammendrag
In recent years the market share for wooden window products has continuously decreased in Europe. Plastics and aluminum have partly replaced wooden window constructions. Service life and maintenance costs lead the customer to a preferable use of other materials than wood. Additionally the use of tropical hardwoods is decreasing because the market demands sustainable alternatives. A transnational research project is initiated to evaluate the use of an alternative wood material for the production of wooden windows. This project involves both, industry and research institutes from Germany, Sweden and Norway. The objective is to establish Kebony furfurylated wood within the window market of the involved countries. Furfurylation of wood using European timbers has been a research topic for many years and is already commercially produced for different applications. The treatment improves dimensional stability, durability and some mechanical properties. This paper presents the first part of the project, where wood properties such as dimensional stability, water sorption, ecotoxicity, capillary water uptake and water vapor diffusion are evaluated.