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
Norway spruce (Picea abies) is widely used not only in Norway but in many other European countries. Due to its refractory behavior after drying it is difficult to impregnate with wood protecting agents that makes it suitable for outside applications. In this research spruce wood samples are exposed to microwave radiation in order to improve the impregnability. The strength properties are evaluated after both microwave and impregnation treatment. The results show, that microwave treatment on spruce wood samples improves the uptake of impregnation agents. With increasing energy absorption due to microwave radiation the impregnability is improved. No differences could be found between the microwave treatments in radial or tangential direction, neither in uptake of wood preservative nor in strength properties. The uptake of impregnation agents in spruce wood is increased by using a pre-treatment with microwave radiation. However, some microwave treatments lead to cracks and a reduction in tangential strength. Most of the values of the process parameters used were obviously too high, which resulted in a distinct crack development.
Authors
Gert-Jan Nabuurs Esther Thürig Nanny Heidema Kestutis Armolaitis Peter Biber Emil Cienciala Edgar Kaufmann Raisa Mäkipää Petter Nilsen Richard Petritsch T. Pristova Joachim Rock Mart-Jan Schelhaas Risto Sievänen Zoltan Somogyi Patrick ValletAbstract
This paper is the outcome of a group discussion held at the Savonlinna meeting ‘Management of forest ecosystems and its impact on the GHG budget’. The aim of this break-out group discussion was to ‘Characterize forest management impacts on the GHG budget of forest ecosystems in different European regions’. In this paper we briefly characterize different options that a forest owner has in order to maintain or maximize forest carbon pools and carbon sequestration. These hectare scale descriptions of measures are then regarded in connection to the current state of European forests and how they can be combined with ongoing management trends and local issues. We point out the various possibilities that exist in European forests, where they are located, and where they could possibly be combined with adaptation. We identify these hotspots for largest growing stocks, largest peat areas, and, e.g. largest risks for loss of carbon due to fire or urban sprawl. We conclude that one common strategy cannot be designed. Within each region, local solutions have to be found that optimize goals and aim at integrated and sustainable land use.
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
Øyvind Nordli Frans-Emil Wielgolaski Anne Kjersti Bakken Stein Harald Hjeltnes Finn Måge Anders Sivle Oddvar SkreAbstract
Data series for bud burst, beginning of flowering and petal fall for 20 species of deciduous trees and conifers at four sites in different regions of southern Norway have been analysed and related to temperature series. On average, the spring phenophases occurred 7 days earlier during the period 1971–2005. The most significant linear trends were observed for the earliest phases. The trends in this period were compared with trends in other periods, the longest one starting in 1927. Those starting in cold decades and ending in 2005 were in most instances statistically significant, whereas hardly any significant trend appeared for series starting in warm decades. This fact showed that the results of trend studies are very sensitive to the choice of starting year. There were significant decadal variations in 40% of the series. The dates of occurrence of the phenophases, varying from the first days of May to the first days of June, correlated with seasonal temperature series, in most cases strongest to mean temperatures for the seasons March–May and April–May. The North Atlantic Oscillation Index (NAOI) for January and February appeared to have some predictive power for the date of occurrence of the recorded phases. The basis for this may be that the oscillations described by the index are of importance for the fulfilment of physiological chilling requirements needed to break bud dormancy. The same genotypes of the trees were grown in region West Norway and in Central Norwegian region; during the period 1965– 2005 the trends towards earlier bud burst were more pronounced and steeper at the western site.
Authors
Anna Martha Elgersma Shivcharn S. Dhillion Arnold Arnoldussen Josef Fanta Eva BoucníkováAbstract
No abstract has been registered
Authors
S. Craig DeLong Glenn D. Sutherland Lori D. Daniels Ben H. Heemskerk Ken Olaf StoraunetAbstract
Patterns of tree mortality, rates and type of tree and snag fall, and relationships between snag characteristics and potential wildlife habitat value were estimated for hybrid spruce (Picea glauca (Moench) Voss x engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in eastcentral British Columbia in order to provide important parameters for deadwood modelling. We sampled 172 snags (52 spruce and 120 fir) for species, size, morphological, and habitat attributes, and used dendroecological techniques on a subsample of these (n = 158) to estimate year of death. Input of snags appeared to occur at a nearly constant rate in these stands. Estimated annual tree fall, including live trees and snags, was 5.3% for hybrid spruce and 6.1% for subalpine fir and stem breakage was more frequent than uprooting. Long-term annual snag fall rates were 4.6% for hybrid spruce and 2.9% for subalpine fir. Discriminant analysis based on time since death correctly classified snags into three decay classes for 85% and 72% of spruce and fir, respectively. Snags that potentially could provide important functions for wildlife habitat were more prevalent in fresh and intermediate classes for hybrid spruce and in intermediate and old classes for subalpine fir. The results provide valuable parameters for further development of deadwood models, which are an important tool for development of best practices for deadwood management.
Authors
Daniel Kwaku A. Asante Anne-Katrine Ree Rosnes Anna Holefors Ragnhild Nestestog Stein E. Lid Jørgen A. Mølmann Jorunn Elisabeth Olsen Øystein Johnsen Olavi Junttila Carl Gunnar FossdalAbstract
Studies have implicated the involvement of the phytochrome light receptors in adaptation of trees to light climate, but the molecular basis of this in gymnosperms is less understood. The promoter regions of plant genes are modular and contain a number of cis-acting elements, each of which may contribute to one or more aspects of a complex expression profile. As a step towards characterization of Norway spruce phytochromes at the transcript level, we isolated fragments (between 700-1500 bp upstream of their putative ATG translational start) of phytochrome N, O and P promoters...
Authors
Daniel Kwaku A. Asante Igor A. Yakovlev Carl Gunnar Fossdal Anna Holefors Lars Opseth Jorunn Elisabeth Olsen Olavi Junttila Øystein JohnsenAbstract
Short days (SD) trigger cessation of elongation growth and transition from an actively growing apex to a terminal bud in woody plants of the temperate and boreal zones. The molecular basis behind this is not well understood in gymnosperm forest trees such as Norway spruce. By combining suppression subtractive hybridization (SSH) libraries and monitoring of gene expression using quantitative RT-PCR analysis, we aimed to identify genes involved in photoperiodic control of growth cessation and dormancy induction in Norway spruce. The gene expression patterns described here will be useful for future detailed functionalanalyses.
Authors
Jørund Aasetre Vegard GundersenAbstract
Almost 80 % of Norwegians live in urban areas, making urban forests highly valuable. The multitude of values assigned to those forests creates conceptual challenges, especially incorporating humanistic and existentialistic views of man. The aim of this presentation is to propose a value taxonomy for urban forests that takes such views of man into consideration, and to suggest how this can be useful to managers. Methodologically the taxonomy is developed through a literature review of environmental philosophical and recreation management literature, and then tested through qualitative interviews with selected stakeholder groups in urban forests near Trondheim, Bergen and Oslo. Through the literature review demand values, instrumental values and constitutive values were identified as key categories. Demand values are utilitarian values appreciated for their own sake, while instrumental values are valued as means to get other values. Such concepts are used in philosophy by Ariansen (1997) and psychology by Rokeach (1973). Constitutive values are genuine non-utility values contributing to our deep felt self understanding, often subdivided into ethical, cultural identity and religious – spiritual values. Introducing constitutive values may help avoiding the trap of the `commodity metaphor` in the often utilitarian oriented management literature...
Authors
Mari Mette Tollefsrud Roy Kissling Felix Gugerli Øystein Johnsen Tore Skrøppa Rachid Cheddadi W.O. van der Knaap Magorzata Lataowa Ruth Terhürne-Berson Thomas Litt Thomas Geburek Christian Brochmann Christoph SperisenAbstract
Norway spruce (Picea abies [L.] Karst.) is a broadly distributed European conifer tree whose history has been intensively studied by means of fossil records to infer the location of full-glacial refugia and the main routes of postglacial colonization. Here we use recently compiled fossil pollen data as a template to examine how past demographic events have influenced its modern genetic diversity...