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
Tore SkrøppaAbstract
No abstract has been registered
Authors
Vegard Gundersen Lars Helge FrivoldAbstract
We reviewed 53 studies of forest landscape preferences carried out as quantitative surveys in Finland, Sweden and Norway and published between 1972 and 2006. Most of them were related to boreal coniferous forests in which even-aged forestry had been the rule. There was a great diversity in survey designs, ranging from nation-wide or regional surveys where target populations and sampling frames were clearly defined, to studies where neither a target population nor a sampling frame could be identified. The latter type of surveys, however, often had a high validity, with measurements made either in the forest or indoors by use of colour slides or advanced digital imaging. A common feature was that people¿s preferences for a forest stand increased with increasing tree size and advancing stage of stand development. Some surveys indicated that the public tended to give high scores to irregular stands with a mixture of trees of different sizes, but on the other hand, a feeling of accessibility and provision of a view was also very important. Large clear-cuts and obvious traces from forest operations were little appreciated. Trained foresters were more positive to clear-cuts than the general population. Few studies included virgin stands, and those that did mostly found low scores for unmanaged forests. Preferences appeared to be fairly stable over time. Elderly or handicapped people, and children and young adolescents, were strongly underrepresented in the surveys.
Authors
Nicholas Clarke Nathalie Cools John Derome Kirsti Derome Bruno De Vos Alfred Fuerst Anna Kowalska Rosario Mosello Gabriele A. Tartari Erwin Ulrich Nils KönigAbstract
Over the past years considerable efforts have been made to improve the quality of laboratory analyses in the various monitoring programmes within the framework of the ICP Forests programme. The Soil and Soil Solution, Deposition and Foliage and Litterfall expert panels have carried out a number of ring tests and held discussions on quality control. The expert panels’ subgroup, \"Working Group on QA/QC in Laboratories\", has extended its activities from the quality control of water analyses to encompass all forms of laboratory analysis, and now also includes experts in the fields of soil, foliage and litterfall. This paper presents all the quality control methods that have been devised for the relevant fields of analytical chemistry. The aim is to provide those laboratories carrying out analyses within the ICP Forests programme with a complete overview of the possibilities of applying quality control in their laboratories.
Authors
Hui Liu Sarah J. Coulthurst Leighton Pritchard Peter E. Hedley Michael Ravensdale Sonia Humphris Tom Burr Gunnhild Takle May Bente Brurberg Paul R.J. Birch George P.C. Salmond Ian K. TothAbstract
No abstract has been registered
Authors
Svein Ole Borgen Onno van BekkumAbstract
No abstract has been registered
Authors
Carl Jonas Jorge SpetzAbstract
No abstract has been registered
Abstract
The difficulty in subculturing biotrophic fungi complicates etiological studies related to the associated plant diseases. By employing internal transcribed spacer rDNA-targeted quantitative real-time polymerase chain reaction, we now show that the heteroecious rust Thekopsora areolata, commonly associated in natural conditions to sapling shoots and cones of Norway spruce and leaves of wild bird cherry, frequently infects nurserygrown seedlings of the conifer. A spatial sampling scheme was used to investigate seedlings and saplings of Norway spruce showing phloem necrosis: the highest concentration of DNA of T. areolata was recorded in the area with necrotic phloem. The separate analysis of bark and wood tissues suggested that the initial spread of the rust to healthy tissues neighboring the infection site takes place in the bark. A Phomopsis species found to coexist with T. areolata in several seedlings showed very high DNA levels in the upper part of the lesion, and even in the visually healthy proximal tissues above the lesions, which indicates that the ascomycete, most probably a secondary invader following primary infection by T. areolata, has a latent stage during early host colonization. We hypothesize that this hemibiotrophic mode of infection contributes to the successful coexistence of Phomopsis with a biotrophic rust.
Authors
Anders BrynAbstract
The forest limits of south-east Norway have expanded to higher altitudes. Two main processes are believed to cause these changes; re-growth after abandonment of human utilisation and recent climate changes. This article aim at separating the effects of these two processes on the upper forest limits and recent forest expansion. The results show that raised forest limits and forest range expansion often attributed to recent climate change is rather the product of re-growth, a process that was climatically retarded from 1959 to 1995. From 1995 to 2006, the data indicate a preliminary effect of climate change escalating the re-growth and probably pushing the future forest limits to higher altitudes.
Authors
David Bredström Patrik Flisberg Linda Rud Mikael Rönnqvist Mikael RönnqvistAbstract
This is a manual for the Refinery Optimization Platform ROP which is a flexible platform for studying refinery production planning. The user can model the overall refining process in a multiperiodic setting, with linear and nonlinear representation of the refinery processes. All input and output is communicated via Excel sheet, where the user can define a general refining process together with required output reports. ROP enables the user to study the planning problem by experimenting with alternative modeling approaches and restrictions. A case study with input data and results is presented.
Authors
David Bredström Patrik Flisberg Mikael Rönnqvist Mikael RönnqvistAbstract
In this paper we present a general model and solution approach for refinery process planning. The model is nonlinear and has a flexible description to account for different configurations at a refinery. The solution approach is based on solving the nonlinear model directly with a commercial solver. Since the model is highly nonlinear we apply a special procedure to find a good starting solution. We test standard commercial nonlinear solvers on a set of standard test examples.