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
Authors
Anne Kristine Søvik Nina SyversenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Janneche Utne Skåre Christiane Kruse Fæste Helle Katrine Knutsen Jan Alexander Augustine Arukwe Trine Eggen Gunnar Sundstøl Eriksen Kari Grave Amund Måge Anders RuusAbstract
No abstract has been registered
Authors
Gert Andersson Patrik Flisberg Bertil Lidén Mikael RönnqvistAbstract
We describe the decision support system RuttOpt, which is developed for scheduling logging trucks in the forest industry. The system is made up of a number of modules. One module is the Swedish road database NVDB, which consists of detailed information of all of the roads in Sweden. This also includes a tool to compute distances between locations. A second module is an optimization routine that finds a schedule, i.e., set of routes for all trucks. This is based on a two-phase algorithm where linear programming and a standard tabu search method are used. A third module is a database storing all relevant information. At the center of the system is a user interface where information and results can be viewed on maps, Gantt schedules, and result reports. The RuttOpt system has been used in a number of case studies and we describe four of these. The case studies have been made in both forest companies and hauling companies. The cases range from 10 to 110 trucks and with a planning horizon ranging between 1 and 5 days. The results show that the system can be used to solve large case studies and that the potential savings are in the range 5%¿30%. Nous décrivons le système d¿aide à la décision RuttOpt, qui a été développé pour planifier le déplacement des grumiers dans l¿industrie forestière. Le système est composé de plusieurs modules. La base de données des routes suédoises (NVDB), qui contient des informations détaillées sur toutes les routes de la Suède, est l¿un de ces modules. Ce module contient également un outil qui permet de calculer la distance entre deux endroits. Un deuxième module est constitué d¿un sous-programme d¿optimisation qui permet de générer un calendrier de transport, c.-à-d. un ensemble de trajets pour tous les camions. Cette opération est réalisée à l¿aide d¿un algorithme à deux phases dans lequel la programmation linéaire et une méthode de recherche tabou standard sont utilisées. Le troisième module est une base de données qui permet d¿emmagasiner toutes les informations pertinentes. Au c@our du système se trouve u interface utilisateur qui permet de visualiser les informations et les résultats par le biais de cartes, de graphiques de Gantt et de rapports des résultats. Le système RuttOpt a été utilisé dans le cadre de plusieurs études de cas et nous décrivons quatre de ces études. Les études de cas ont été réalisées chez des compagnies forestières et des entreprises de transport. Selon le cas, le nombre de camions varie de 10 à 110 et l¿horizon de planification d¿un à 5 jours. Les résultats montrent que le système peut être utilisé pour résoudre des études de cas de grande taille et que les économies potentielles sont de l¿ordre de 5 % à 30 %.
Authors
Jim Treasurer Oddvar Ottesen Richard Fitzgerald Julie Maguire Nonna Zhuravleva Celine ReboursAbstract
No abstract has been registered
Abstract
Arthropods were collected by fogging the canopy of Scots pine Pinus sylvestris selected from a 2 km2 boreal forest area in Sigdal, Norway with the overall purpose to examine whether there were faunal differences in the representation of arthropods among mature and old trees, and specifically for this paper, the biting midges (Ceratopogonidae). Target trees were chosen as pairs, one mature (70-110 years) and one old (250 years or older) tree from six different stands. All knock-down treatments were performed in June and July 1999, before dawn and after a dry and windless night. Knocked-down arthropods were collected in plastic funnels placed systematically on the ground. Funnels remained in place for circa one hour after treatment. Among the 61 species records new to Norway, the most frequently encountered taxon of invertebrates was Diptera, and the family of biting midges, Ceratopogonidae, comprised 30 of 61 (49%) of all new records, compared with the overall species numbers showing 40 biting midges of 193 recorded species (21%). Among the Ceratopogonidae new to Norway, two species new to science and two first records from Europe were found. Coleman rarefaction curves were constructed by running 500 iterations without replacements using EstimateS and showed that there were significantly more new records of Diptera in old trees in comparison with mature trees. A similar pattern of significance (by comparing standard deviations estimated by EstimateS) was found for Diptera when Ceratopogonidae was excluded. New species records of Ceratopogonidae were more common in old trees than in mature trees, although not significantly so. No predominance of new records in old trees was found for arthropods other than Diptera. Old trees are rare and may provide a variety of resources (e.g. resting sites, places to over-winter, hiding places, sites for oviposition, larval habitat, etc.) that are rarely found in younger trees. Thus, the high number of new species records probably result from studying a whole arthropod taxon (Diptera) in a part of a forest ecosystem (canopies) with a suite of microhabitats (old pine trees) that in combination has been poorly investigated earlier.
Authors
Espen Govasmark Bal Ram Singh John A. MacLeod Mark G GrimmettAbstract
Selenium (Se) deficiency in Scandinavian soils is a common problem, and crops generally contain inadequate amounts to meet human need. This study shows a relationship of the Se concentration in spring wheat (Triticum aestivum L., c.v. 'Helena') and leaching water with timing of nitrogen (N) [as ammonium nitrate (NH4NO3)] and Se [as sodium selenate (Na2SeO4)] application. Ammonium-nitrate was applied by two methods (i) whole amount at sowing and (ii) in split application as 75% at sowing and 25% at stem elongation. Selenate was applied at cereal growth stages after sowing, e.g., tillering, stem elongation, head emergence, and milking. Split N application in comparison to one N application increased the grain protein content from 12.1 to 13.7 mg g(-1), and grain Se was increased from 0.8 to 1.1 mg kg(-1) when Se was applied at stem elongation and from 0.6 to 0.9 mg kg(-1) when applied at heading. The highest Se concentration in plant was achieved with the split N application and Se application at stem elongation or heading. Selenium leaching losses increased with increasing selenium concentration in the wheat grains. No differences in Se leaching losses were obtained with split N application. Applying selenate and ammonium-nitrate together after tillering increased the grain Se concentration, but did not affect the potential leaching of Se, and thus could be considered as an appropriate time of application of these elements.
Authors
Peder GjerdrumAbstract
Pine (Pinus sylvestris) heartwood and pine sapwood can, in several respects, be considered two different timber products. Sapwood demonstrates open structures that easily adsorb moisture and is vulnerable to bio-chemical disintegration, but also more easily painted, glued or impregnated. Heartwood, on the other hand, is less disposed to moisture fluctuations, hence, more dimensionally stable, and durable. Heartwood content is closely related to cambial age and to the progress of annual ring width. It is also the nature of pine is to grow timber of quite varying quality along the stem. Resins are more abundant near the base, and the knottiness is shifting, following certain patterns from the base upwards. Several of those traits can be identified prior to breakdown, applying specific wood technology knowledge, recent research and standard log scanner equipment. Even with this potential for producing more homogeneous board quality by including heartwood in the breakdown decision basis, one should not forget the practical implications for the sawmill. The cost of keeping separate heartwood quality classes and the risk of mistakes might easily exceed the price gain.
Abstract
No abstract has been registered
Authors
Jan Stenlid Åke Olson Kerstin Dalman Magnus Karlsson Mikael Brandström Karl Lundén Carl Gunnar Fossdal Matteo Garbelotto Frederick AsiegbuAbstract
Heterobasidion annosum s.l. causes a devastating root rot in conifer plantations and natural forests throughout the northern hemisphere. The genome sequencing of H. annosum will provide the first comprehensive genetic information on a plant pathogenic homobasidiomycete allowing for new insights into plant-microbe interactions with trees, in particular conifers. It is important to broaden the taxonomic base for understanding the mechanisms of plant-microbe interactions, studying genes and proteins involved, and identifying pathogenicity determinants. Comparative genomics of plant pathogens with a gradient of taxonomic relatedness to H. annosum will help to understand the evolution of such factors. The project involves resequencing of several species in the H. annosum species complex including pathogenic and non-pathogenic species. Comparisons can also be made with fungi with different nutritional relations to plants; necrotrophic, biotrophic and mycorrhizal mutualist. The project integrates genetic approaches e.g QTL mapping with comparative genomics. Data bases generated on genes under positive selection in the sequenced genomes will be compared with candidate genes derived from published QTL mapping and EST-projects but also known pathogenicity factors in other pathosystems.