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.
2000
Authors
Knut FinstadAbstract
No abstract has been registered
Authors
Erik Christiansen Alan A. Berryman Vincent R. Franceschi Trygve Krekling Paal Krokene Nina Elisabeth Nagy Halvor SolheimAbstract
No abstract has been registered
Abstract
A rapid and sensitive method was developed to discriminate between Seiridium cardinale and Seiridium cupressi, the fungi causing severe cankers on common cypress in the Mediterranean area. The method amplified sequence variants in the ITS2 region of ribosomal DNA using the polymerase chain reaction (PCR), followed by polyacrylamide gel electrophoresis, to reveal single-strand conformation polymorphism (SSCP) between the two species. The greatest separation pattern was obtained with a gel matrix containing 7-10% formamide and 3-5% glycerol under optimized running conditions, which were found to be 30-40 V at 4-5 degrees C for 4-8 h. Sequence homology among isolates within each of the two species caused no mobility shifts, with all isolates displaying the same migration pattern. A few base differences between S. cardinale and S. cupressi caused markedly different migration patterns, allowing differentiation of the two pathogens. Differences between these fungi at the genetic level are consistent with known data on morphological, physiological and pathogenic characteristics. SSCP analysis constitutes a rapid and easy-to-perform method by which to recognize and distinguish closely related organisms, and has considerable potential for use in diagnosis and taxonomy.
Authors
Anne Moxnes Jervell Svein Ole BorgenAbstract
No abstract has been registered
Abstract
The beetle fauna of 299 sporocarps of the bracket fungus Fomitopsis pinicola in a 200 ha spruce forest in southeastern Norway was investigated in relation to sporocarp, tree and forest variables. The sporocarps contained 36 species of beetles, of which six species are on the Norwegian Red List. Of 12,373 individual beetles collected, 91 % were Cis glabratus. Plots of species accumulation curves suggested that there may be more than 60 beetle species present in F. pinicola in the area, but that probably all the specialist Ciidae were found. The major factor influencing beetle diversity turned out to be the level of dead wood at and in the vicinity of the sampling site, with a higher number of species per unit volume of sporocarps in areas with high levels of dead wood. There were also significantly more red-listed species in those areas. Analysing the species occurrence with stepwise logistic regression, we show preferential habitat selection of the six most abundant species of Ciidae. Conservation of beetles associated with bracket fungi using amount of dead wood as a surrogate measurement is discussed.
Authors
Jenny Fäldt Halvor Solheim Bo Långström Anna-Karin Borg-KarlsonAbstract
No abstract has been registered
Abstract
Agriculture in Latvia has been going through major reforms since 1991. State farm ownership exists only in a negligible quantity only for research and training purposes and most of the land has been returned to its previous owners, or their descendants, from the times before collectivization. During the Soviet period a number of collective farms were established. Most of these still exist, but the legal form has been changed and they operate on private owned land. Also new ones have been formed. As a result of the agricultural reforms, the accounting, tax and statistical systems that had been established in the old structure were no longer applicable. An urgent need thus arose for the development of new systems for the large number of new family farms. NILF became involved in this work on initiative of the Agricultural University of Norway (NLH), which at that point was cooperating with the Latvian Agricultural University, and was already planning several projects in Latvia in 1993. In cooperation with the Latvian State Institute of Agrarian Economics (LVAEI), NILF was to assist in the development of systems for collecting and making use of financial data for individual farm management and the development of Latvian agricultural policy. The project received financial support from the Ministry of Foreign Affairs' Program for Cooperation with Central and Eastern Europe, and got under way in the summer of 1996. A project unit was established within LVAEI, which was responsible for all work regarding farm statistics. This included the establishment of farm statistics, adaptation to the European Union's Farm Accountancy Data Network (FADN), as well as systems for farm planning. The adaptation to FADN received some support and training assistance from a Danish project. NILF's project constituted the major part of the LVAEI project unit, both with regard to work load and funding. From the Norwegian point of view, the cooperation with the Latvian project unit functioned extremely well, and the unit has continued following the completion of the project. [...]
Authors
Per Holm Nygaard Heleen A. de WitAbstract
Elevated concentrations of aluminium (Al) which have been hypothesized to limit root growth of forest trees as well as nutrient uptake, are believed to be a major threat to forest vitality. Direct toxicity of Al, causing decreased root growth has been observed in several nutrient solut ion studies and in some pot experiments using seedlings.However, direct support for the occurrence of decreased root growth in mature forest stands is scarce. Despite the uncertainty concerning effects of ambient concentrations of Al in soil water on fine roots, the concentrations of dissolved Al in forest soils has been assigned a key role in models used to calculate critical loads.Here we present results of three years of artificial additions of Al on fine root growth in a mature stand of Norway spruce (Piece abies). During the growing season the average concentrations of dissolved inorganic in soil water at 10-cm soil depth ranged from about 1 mol L-1 (control) to 120 mol L-1 (highest Al treatment).According to nutrient solution studies the established concentrations of dissolved inorganic Al reached levels that may be toxic. In addition, the Ca/Al ratios were well below 1.0, a value, which is regarded as a lower limit below which negative effects on vegetation may be expected.So far, no effects on fine root growth, root mortality and root distribution has been observed. Chemical analysis of the fine roots indicate a lower molar Ca/Al ratio in living fine roots of 0-20 cm depth and dead fine roots 0-40cm in the Al treatments compared to controls.Our study does not support the critical load assumption that Ca/Al 1 in soil solution is critical to fineroots, as shown by some culture solution experiments. The molar Ca/Al ratio of fine roots mainly reflect the soil chemical composition, which has a steep depth gradient So far, three years of Al additions has shown that the soilmatrix is an extremely robust growth medium, which can sustain high inorganic Al concentration and low Ca/Al ratios.The results show clearly that the value of Ca/Al or BC/Al as used in critical load calculation and plant soil modeling, may have to be reconsidered.
Authors
Jan Mulder J.F. Gallardo Lancho E. Matzner Edward Tipping Charlotte Bryant Nicholas Clarke S. Lofts B. Michalzik A. Vicente EstebanAbstract
No abstract has been registered
Authors
Halvor TorgersenAbstract
This article describes an investigation of fatigue resistance in different steel wire rope constructions used in Norwegian cable logging operations. Test results indicate the following: A clear difference in fatigue resistance between ropes (approximately 50% decreased endurance for the compacted rope of highest density). Differences in rope wear for varying angles of deflection. A correlation between the number of visible broken wires and remaining strength in the rope.