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.
2008
Abstract
No abstract has been registered
Abstract
New restrictions draw governments, industry and research towards new and environmental benign wood protective agents. These agents often come from a natural source, and are also a waste product. One of these is chitosan. Chitosan is a derivative from chitin, mainly found in the exoskeleton of crustacean. Some research has been conducted on chitosan and wood. Chitosan has earlier proven good antifungal effectiveness, but to achieve a good protection, a 5 % concentration is needed, which makes the end product quite expensive. In recent research, a way to make chitosan treated wood hydrophobic has been invented. The objective of the research presented in this paper, is to describe the effectiveness of the following compounds: Chitosan, chitosan/copper, chitosan/boron and chitosan/Scanimp (a commercial wood preservative). Results show that chitosan works well alone, but has a fixation problem. Chitosan and boron give good fixation, and reduced amounts of chitosan and together give good protection against wood destroying fungi. The fire protection agents are promising, but needs higher concentration and/or better fixation to give a sufficient protection against wood destroying fungi
Authors
Erik ChristiansenAbstract
Hylobius abietis L. feed on the stem bark of conifer seedlings. In the absence of appropriate control measures, the damage may reach a level that rules out planting as a means of conifer regeneration. It is distributed throughout the coniferous forests of northern Eurasia, including the British Isles and Japan. Other Hylobius species cause damage of a similar type, both within this area, and in North America. Soon after the introduction of clear felling systems in Central Europe, damage by H. abietis became wide-spread.
Authors
Erik ChristiansenAbstract
Among thousands of bark beetle species worldwide, only a handful is able to attack and kill trees on a large scale. One of these is the 8-toothed spruce bark beetle, Ips typographus L., indigenous to the Palaearctic forests and recently introduced into North America. In Europe, the main host is the Norway spruce, Picea abies (Linnaeus) Karsten; in Eastern Asia, including Japan, the main hosts are spruces of the P. jezoensis group. In unmanaged forests, these beetles play an important ecological role by killing old trees and stands, thus promoting biomass recycling and ecosystem rejuvenation. Foresters who are faced with extensive tree mortality do not, however, welcome this activity: managed forests of Europe have lost hundreds of millions of trees in recurring outbreaks
Authors
Peder Gjerdrum Anna BarszczAbstract
The present research concerned selected characteristics of knottiness of large-dimensioned spruce timber (of trees with the minimum breast-height diameter of 40 cm over bark) from three stands, over one hundred years old, located in south-eastern Norway. Fourteen sample trees were felled and measured, and knots which occurred in them were classified into three categories of healthiness and three categories of tightness with the surrounding wood. Sound and tight knots were dominant in the timber under analysis. All categories varied significantly in relation to average diameters, relative diameters (related to stem thickness at the points where the knots occurred) and the relative height of location along merchantable boles. The researches analysed the significance of relations of diameters or relative diameters of knots with the relative height of their location along merchantable boles...
Authors
Nicola La Porta Paolo Capretti Iben Margarethe Thomsen Risto Kasanen Ari M. Hietala Kim von WeissenbergAbstract
Most atmospheric scientists agree that climate changes are going to increase the mean temperature in Europe with increased frequency of climatic extremes, such as drought, floods, and storms. Under such conditions, there is high probability that forests will be subject to increased frequency and intensity of stress due to climatic extremes. Therefore, impacts of climate change on forest health should be carefully evaluated...
Authors
Clemens Reimann Belinda Flem Arnold Arnoldussen Peter Englmaier Tor Erik Finne Friedrich Koller Øystein NordgulenAbstract
Le Roux et al. consider the approach that led to the above article as trend-setting. However, according to Le Roux et al. the data are unfortunately ‘‘inappropriately interpreted”. It is appreciated that le Roux et al. took the effort to study the original data and attempted a re-interpretation along the lines of an impressive list of publications which they claim have been ignored by Reimann et al. (2008). Here the achievements and shortcomings of their alternative interpretation will be discussed in view of the facts substantiating the conclusions of the original article......
Abstract
The inhibitory effect of methanol bark extracts from six deciduous and three coniferous European tree species were bioassayed against eight fungi from the different damage categories, brown rot, white rot, canker and blue-stain. This is the first report providing data on the antifungal activity of several Europaen tree species against fungi within these damage categories. Generally the decay fungi were more inhibited by the bark extracts than the blue-stain fungi, while the lowest inhibition was found among the cancer fungi. The main pattern found between the fungal groups in relation to the bark extracts in this study is believed to be caused by the route of ingress. Acer platanoides bark extract proved to be the most effcient bark extract tested, significantly reducing the growth rate of all tested fungi. Betula pubescens bark extract generally gave the weakest reduction in growth rate. In this study, the conifer bark extracts were in general more active against the canker and blue stain ascomycete fungi than the deciduous trees extracts.
Authors
Clemens Reimann Belinda Flem Arnold Arnoldussen Peter Englmaier Tor Erik Finne Øystein NordgulenAbstract
The recent article entitled ‘‘The biosphere: A homogenizer of Pb-isotope signals` has attracted considerable interest from other researchers in this area. According to the critical comments by Bindler and Shotyk, the authors have supposedly neglected a substantial body of the literature and especially the reported temporal changes in Pb-isotope ratios in a variety of sample materials. They conclude that the urban transect is not appropriate for defining natural variation, and state that a substantial body of research indicates a limited uptake of Pb in plants.......
Authors
Tove Maria Østensvik Kaj Bo Veiersted Emmanuel Cuchet Petter Nilsen Jan Johansson Hanse Caisa Carlzon Jørgen WinkelAbstract
The present cross-sectional study was performed to analyze potential risk factors for upper extremity disorders in two groups of forest machine operators driving harvesting vehicles and performing equal tasks in France (n=18) and Norway (n=19). This comparative design implied similar work tasks, but potentially different external work demands. Previous studies have suggested higher levels of neck and shoulder complaints among Norwegian operators compared to those of the French. This may be related to different external work demands and/or individual motor performance. Surface electromyography (EMG) of the right upper trapezius (RUT) and extensor digitorum (RED) muscles were measured continuously during 1 working day (7.5–8 h per operator) and video of body postures was recorded inside the cabin (1 h per operator). A questionnaire on external work demand factors and psychosocial stressors was used together with the collection of symptom data. A physical examination was performed on all workers. Borg's CR-10 scale of intensity of discomfort/pain was rated four times throughout the test day. The French operators reported less complaint (p<0.01) in the right neck compared to their Norwegian colleagues. Furthermore, the French had on average two to three times longer lunch breaks during 5 work days, less continuous hand intensive use of the control lever with more frequent short breaks during the test day compared to the Norwegian operators. However, the average static load level on the RUT muscle for the whole working day was significantly higher among the French (0.7% EMGmax) in comparison with the Norwegian operators (0.3% EMGmax). No difference was found in number of periods with sustained low-level muscle activity neither in the RUT nor the RED muscle. In conclusion, our results support that the higher prevalence of discomfort/pain among the Norwegian forest machine operators may be related to organizational factors.