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.
2011
Authors
Arnold ArnoldussenAbstract
Publiced earlier in English in 2006. In 2011 revised and translated into Chinese.
Abstract
No abstract has been registered
Abstract
Current risk assessment procedures for contaminated land and for pesticides often fail to properly characterize the risk of chemicals for environment or human health and provide only a rough estimate of the potential risk of chemicals. Chemicals often occur in mixtures in the environment, while regulatory agencies often use a chemical-by-chemical approach, focusing on a single media, a single source, and a single toxic endpoint. Further, the importance of soil microbes and their activity in the functioning of soils impose a need to include microorganisms in soil quality assessments including terrestrial ecotoxicological studies. Numerous papers have been published on the effects of different contaminants on soil microbes, establishing changes in soil microbial diversity as an indicator of soil pollution. However, only a limited number of molecular studies focus on changes in fungal species when investigating soil microbial diversity. The main objective of the study presented here, is to assess the applicability of changes in soil microbial diversity and activity levels as indicators of ecologically relevant effects of chemicals contamination. We will achieve this through studies of effects of the fungicide picoxystrobin and the chemical 4-n-nonylphenol on the microbial biodiversity in a Norwegian sandy loam, with focus both on prokaryotes and the fungal species. Laboratory incubation experiments at 20°C with soil samples treated with the single chemicals or mixtures, with continuous monitoring of respiration activity as well as occasional destructive sampling for extraction of soil DNA, RNA, and chemical residues, was performed through a 70 d period. Results from amplification of soil bacterial and fungal DNA followed by T-RFLP (terminal restriction fragment length) analyses to assess chemicals effects on soil microbial diversity, indicate significant effects of the studied chemicals on soil microbial community structure. To identify specific bacterial or fungal groups that are affected, an assessment of the effects of the chemicals on the soil microbial metagenome by high throughput shot-gun sequencing (454 sequencing) is in progress This work is part of the research project ‘Bioavailability and biological effects of chemicals - Novel tools in risk assessment of mixtures in agricultural and contaminated soils’ funded by the Norwegian research council.
Abstract
Wood as a hygroscopic material gains or loses moisture with changes in climate of the surrounding air. The moisture content influences strength properties, hardness, durability and machinability. Therefore the hygroscopicity is a very important property, last but not least for economic factors. Below fibre saturation, a change in moisture content causes shrinkage or swelling and anisotropic behaviour can be seen in the different growth directions. For a better understanding of the sorption behaviour of Scots pine (Pinus sylvestris L.) the variation between different adsorption and desorption curves has been investigated. Trees from 25 different sites in Northern Europe were collected and 3651 samples (1510 heartwood- and 2141 sapwood-samples) measuring 5 (T) x 10 (R) x 30 (L) mm were obtained. The sorption isotherms for all specimens were measured at 25 °C at relative humidities of 15, 35, 55, 75 and 95 % for both desorption and adsorption. The aim of this study is to investigate the influence of raw material variability on the sorption behaviour of Scots pine. Due to the different growing conditions, densities and wooden material (heart or sapwood) variations within the sample groups have been found. Correlations between moisture and density respectively latitude were investigated.
Authors
Amy M P Oen Barbara Beckingham Upal Gosh Marie Elmquist Kruså RG Luthy Thomas Hartnik Thomas Henriksen Gerard CornelissenAbstract
No abstract has been registered
Authors
Fride Høistad ScheiAbstract
No abstract has been registered
Authors
Dawit Solomon Johannes Lehmann Katrin Knoth Julia Dathe James Kinyangi Biqing Liang Stephen MachadoAbstract
No abstract has been registered
Authors
May Bente Brurberg Abdelhameed Elameen Vinh Hong Le Ragnhild Nærstad Arne Hermansen Ari Lehtinen Asko Hannukkala Bent Nielsen Jens Hansen Björn Andersson Jonathan YuenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Introduction: Windstorm is one of the most destructive environmental disturbance factors on forests, but its influence on conifer defense chemistry and susceptibility to insects and diseases is not well understood. Materials and methods: We selected groups of 10 Norway spruce trees with short leaders, leaning stems, or no apparent damage 17 months after the largest storm ever recorded in Sweden. Trees were mass-inoculated with Ceratocystis polonica, a virulent blue stain fungus associated with the spruce bark beetle (Ips typographus) to estimate tree resistance. Terpene and phenolic composition in the bark was analyzed by gas chromatography–mass spectrometry, two-dimensional gas chromatography, and liquid chromatography. Results: In contrast to our hypothesis, the results showed that trees with no apparent damage were more susceptible to C. polonica inoculation than short-leader and leaningstem trees. Chemical composition also differed between trees in different damage classes. (+)-3-carene and two unidentified stilbenes were higher, and taxifolin glycoside was lower in trees without apparent damage than in the others. The relative amount of (−)-α-pinene was negatively correlated, whereas (+)-3-carene, sabinene, (−)-germacrene D, thunbergol and two unidentified stilbenes were positively correlated with fungal performance. Conclusions: These results suggested that wind damage had increased resistance level of short-leader and leaning trees to C. polonica inoculation, and that change in terpene and phenolic composition in the bark could be at least partly responsible for the induced resistance. Different possible explanations for this unexpected finding are discussed.